Happy New Year!


The year of 2018 has come to an end and I would like to wish all of you a happy and healthy new year. I would like to thank the stars of my lab, the students! Thank you for the hard work, enthusiasm and engagement you show in your work. I am very proud of each and every one of you, especially in your willingness to share ideas with your colleagues and help each other. You inspire me every day. Thank you for letting me share your success and join you for a short while on your journey through life.
Thank you clinical colleagues at McGill University Health Centre and Jewish General Hospital and to local, national and international collaborators. Without you very little would have been done.

2018 was a successful year. Three new PhD candidates: Marc Morcos, Yuji Kamio and José Fragoso Negrín, five new MSc candidates: Julien Mégrourèche, Liam Carroll, Joseph DeCunha, Peter Kim and Ximeng Mao, five undergraduate research students: Majd Antaki, Alania Bui, Mira El-Irani, Tristan Shoemaker and Sam Thibodeau and the programming and medical physics loving MD, Harry Glickman joined the lab.

Julien, Joseph, Liam, Tristan and I visited Uppsala University in Sweden for two months during the summer. Thank you professors Anders Ahnesjö, Mark Lubberink and Filip Heijkenskjöld for hosting us.

We have filed several patents and published four peer reviewed articles in Physics in Medicine and Biology, Brachytherapy, Radiotherapy and Oncology as well as International Journal of Radiation Oncology Biology Physics. Two additional manuscripts were tentatively accepted in International Journal of Radiation Oncology Biology Physics and one new manuscript was submitted. One of our published papers was selected as the Issue Highlight by the editor of Radiotherapy and Oncology.

Gabriel Famulari’s project AIM-Brachy was selected as one of the 5 finalists out of 42 projects in McGill Clinical Innovation Competition and Hakim Family Prize. Vincent Turgeon’s abstract was selected as one of the best abstracts to compete in the joint scientific meeting, Young Investigator Symposium at CARO-COMP-CAMRT. Gabriel Famulari’s abstract was selected as one of the five abstracts out of the numerous submitted abstracts to the European Society for Radiotherapy and Oncology (ESTRO) conference to highlight the type of innovative science presented in an area and was published in the conference report. Julien Mégrourèche competed in the Cooperathon open innovation challenge launched by the Desjardins Centre for Advanced Training at the research institute of McGill University Health Centre (RI-MUHC). Of the 104 teams participating, Julien´s team was one of the four that made it to the Finals held on November 1, 2018. Paolo Tulino, defended his MSc thesis at University of Pisa with a highest achievable mark, 110/110! An internship at IAEA in Vienna is hopefully the next step. Vincent Turgeon started his medical physics residency at the Jewish general hospital. Best of luck to Paolo and Vincent.

Together with my co-applicants and collaborators, I was awarded with the CHRP - Collaborative Health Research Program (NSERC+CIHR) grant for the project "Novel Delivery System for High Dose Rate Intensity Modulated Brachytherapy with Yb-169 as a Radiation Source" and 1er appel à projets de coopération Québec-Conseil nordique des ministers, "Innovation dans le domaine de la détection de radiation ionisante". Joseph DeCunha was awarded with a MSc award in ”2019 RI-MUHC Studentship Competition”. Yuji Kamio was awarded with NSERC Postgraduate Scholarship-Doctoral award. Gabriel Famulari was awarded with NSERC - Alexander Graham Bell Canada Graduate Scholarship. In addition, Gabriel received Canadian Cancer Society travel award to present his research results at ESTRO (Barcelona, Spain). José A. Fragoso Negrín was awarded with Emerging Leader of America Scholarship from Global Affairs Canada, Government of Canada.

In collaboration with Dr. Joanne Alfieri I supervised five graduate students (engineers (software, biomedical, electrical) MBA and MD) from McGill and Concordia University in clinical innovations. You will read about their innovation in 2019!


Last Days in Uppsala

It is now the final days of my stay in Uppsala and Sweden. With others from my lab group, we traveled here at the beginning of July as a collaboration between McGill University and Uppsala University. While here, we have been graciously hosted by the medical physics department at Uppsala university and the PET (Positron Emission Therapy) department at the Uppsala University Hospital. Throughout the summer, we benefited from many conversations with the various department members who were able to provide insight into our various projects. We also enjoyed conversations on diverse topics that helped highlight the cultural differences between Canada and Sweden. I will certainly miss the kind but reserved Swedes who I met during my two-month stay here.

Out of everyone that I met here in Sweden, there were two individuals who provided me with a lot of insight and guidance for my project which consists of building a new detector for PET. These were Charles Widström and Mark

Liam Carroll at the Skandionkliniken proton therapy center

Lubberink. They are both clinical physicists who work at the Uppsala University Hospital nuclear medicine and PET centers and met with me many times to discuss my work.  Along with guidance, they gave me access to the resources here at the hospital which allowed me to perform experiments that I would not be able to do in Montreal.

Apart from work at the hospital, we all had ample opportunity to travel around and explore Sweden and the nearby countries. Firstly, we had the chance to visit different academic centers and companies, such as the Skandionkliniken proton therapy center, and the Karolinska Institute in Stockholm.

On weekends, there has been ample time to explore a bit further a further afield. While traveling around Sweden and Scandinavia, I’ve noticed that there is a general love for the outdoors and a respect for the environment. This can be seen in the many protected parks and forests and the absolute abundance of bike paths in the cities. As mentioned in the other blog posts, it is very easy to get around most major cities with a bicycle. Apart from the nature, there is a wealth of historical landmarks and museums dotted across Sweden.

Viking Rune Stone

These range from remnants from the vikings to beautiful Gothic cathedrals. During the summer, I had the chance to visit Copenhagen, Helsinki and Stockholm, so I was able to learn a lot about Scandinavian history.


Unfortunately, all good things must come to an end. Now that summer is coming to a close, the student dorms where we have been living are starting to fill back up with students from around the world. This last week has been a small glimpse into what Uppsala is like during the rest of the year. Plenty of young excited students ready to start a new chapter in their lives. While they are all just arriving, I prepare to leave. It has been a fantastic 2 months in Swede. One day, I hope to return.

Liam Carroll


J’en suis déjà rendu à mes dernières journées en Suède.  Je suis venu ici avec trois étudiants de mon groupe de recherche et notre superviseure  pour une collaboration entre l’Université McGill et l’Université d’Uppsala. Pendant notre visite, nous avions comme hôtes les membres du groupe de physique médicale de l’Université. Durant toute l’été, ils ont travaillé avec nous sur nos projets et nous avons bénéficié de plusieurs conversations avec les membres du département. Nous avons aussi discuté de divers sujets qui ont su souligner les différences culturelles entre la Suède et le Canada.

Dans le sous-sol du laboratoire Ångström

De tout le monde que j’ai rencontré ici en Suède, deux personnes m’ont particulièrement aidé à faire avancer mon projet (qui consiste à construire un nouveau détecteur). Mark Lubberrink et Charles Widström sont tous les deux physiciens médicaux et ils travaillent aux départements de TEP (tomographie par émission de positron) et de médecine nucléaire de l’hôpital universitaire d’Uppsala. Durant l’été, je les ai rencontrés à plusieurs reprises pour discuter de mon projet. Ils m’ont conseillé judicieusement et ils m’ont donné accès aux ressources disponibles à l’hôpital. Avec leur aide, j’ai pu procéder à  des expériences qu’il n’est pas possible de faire à Montréal.

Mis à part notre travail à l’hôpital, nous avions tous beaucoup de temps pour voyager et ex

A l’interieur du Vasamuseet en Stockholm

plorer la Suède et d’autres pays voisins. Nous avons fait plusieurs visites guidées de centres académiques et industriels, comme le  centre de protonthérapie de Skandionkliniken et l’Institut Karolinska à Stockholm. Pendant les fins de semaine, nous pouvions explorer plus loin et c’est en voyageant que j’ai constaté que les Suédois adorent la Nature! Il y a un grand nombre de parcs et forêts protégés et il est souvent plus facile de voyager à bicyclette qu’en voiture dans les grandes villes. Mise à part la nature stupéfiante, j’ai aussi voyagé dans diverses grandes villes et petits villages où j’ai appris sur l’histoire des pays scandinaves. À Stockholm, Helsinki et Copenhague, j’ai vu des monuments qui datent de l’âge des Vikings et des palais qui ont été construits dans les années 1900. L’histoire scandinave est vraiment épatante.

Toute bonne chose a une fin. Maintenant que l’été se termine, les résidences où l’on vivait commencent à se remplir de nouveaux étudiants qui viennent de partout dans le monde. Cette dernière semaine nous a donné un aperçu de la vraie Uppsala, une ville remplie d’étudiants prêts à commencer une nouvelle aventure. Pendant qu’ils arrivent, je me prépare à partir. Ces deux mois en Suède furent fantastiques. Un jour, je reviendrai.

Liam Carroll



Uppsala: sixième semaine | Reflecting on six weeks in Uppsala

Salut! Je m’appelle Joseph DeCunha et je suis un étudiant qui travaille avec Dre Shirin Enger. Je suis récemment diplômé d’un BSc en physique de l’Université McGill. Dès septembre,  j’entamerai ma MSc en physique médicale. Je prévois que Dre Enger supervisera ma thèse MSc. C’est maintenant le troisième été que je travaille avec Dre Enger et mes travaux de recherches précédents portaient sur la curiethérapie intravasculaire. En voici un aperçu. Cet été, j’analyse l’effet de la taille des cellules sur la réponse du cancer à la radiation.

Comme les autres chercheurs qui ont écrit sur le blogue,  je suis arrivé à Uppsala le 2  juillet dernier. Initialement, j’étais incertain quant à la raison de mon voyage en Suède. Contrairement à mes collègues comme Liam qui travaille avec de l’équipement propre à Uppsala, je travaille uniquement à l’aide d’ordinateurs et superordinateurs pour ma recherche. Pourquoi devrais-je me rendre en Suède si ce n’est que pour travailler sur le même ordinateur  dans un différent bureau?. Je ne voyais pas les choses de la bonne façon et voici pourquoi.

Pour ma recherche,  je bénéficie grandement de la présence de Fernanda Villegas Navarro et Anders Ahnesjö qui sont tous les deux chercheurs éminents dans le domaine de la microdosimétrie informatique. J’ai de la chance en tant que jeune chercheur de travailler avec des chercheurs plus établis dans mon domaine.

La semaine dernière,  nous avons eu plusieurs expériences bénéfiques. Nous avons rencontré l’un des fondateurs de ScandiDos, Görgen Nilsson. Il nous a parlé des difficultés souvent rencontrées en créant une entreprise. C’est particulièrement difficile parce que les physiciens n’ont généralement pas les compétences d’un entrepreneur. Les physiciens qui développent de nouvelles technologies doivent souvent démarrer leur propre entreprise, ou sinon abandonner leur idée. Aussi, nous avons rendu visite à Dre Åsa Carlsson Tedgren et son étudiante PhD Vaiva Kaveckyte à Karolinska Sjukhuset. C’est toujours bénéfique rencontrer les chercheurs d’une autre institution, notamment pour la possibilité de collaborations futures et pour obtenir un autre point de vue sur sa propre recherche.

Voici quelques photos prises à Uppsala et en Norvège l’autre fin de semaine!


Hello! I am Joseph DeCunha, a student working with Shirin Enger’s research group. I am a recent graduate of the undergraduate physics program at McGill and will be pursuing a MSc in Medical Physics at McGill this coming September. I anticipate that Dr. Enger will supervise my masters thesis project as well. This is my third summer working with Dr. Enger and my first working on a project related to microdosimetry. My past work in Medical Physics has been in Intravascular Brachytherapy and you can read more about that here and here.

Like the other members of the group I arrived here July 2nd and will be leaving Uppsala at the end of August. Initially I was skeptical about the value of going on the trip, unlike my colleague Liam who will be making use of equipment and facilities in Uppsala all of my work is done on my computer and super-computing clusters. What value could there possibly be in working on my computer, but simply at a new desk in a different city? These doubts were misplaced and I will elaborate on some of the reasons why my time in Uppsala has been valuable.

Primarily, my work here has been helped by being located in the same facility as Fernanda Villegas Navarro and Anders Ahnesjö, two renowned researchers who are amongst the few individuals currently doing work in computational microdosimetry. It has been a blessing to be able to drop by Fernanda’s office at the Akademiska Sjukhuset when I’m stuck on something and could use advice related to my research. This type of collaboration would be inefficient if we were only communicating via email or skype, and the amount of communication would surely be limited. I am lucky as a young researcher working in a reemerging field to have been able to spend some time with some of the most established researchers in microdosimetry.

Other valuable experience has been gained through connections and meetings held with other research groups and companies working in Sweden. Last Tuesday, the group travelled to the offices of ScandiDos, a radiation dosimetry company headquartered in Uppsala. There we met Görgen Nilsson one of the founders and CEO of the company. We spoke with them for many hours and they provided a comprehensive overview of their company and the perils and rewards of starting your own company. Many medical physicists who invent new products find themselves faced with the choice of either not pursuing their invention or of having to create their own independent companies in order to ensure their product comes to market. Creating a company can be a terrifying task for a physicist, especially since we are not equipped with the skills and tools to create our own companies.

We also travelled to the Karolinska Sjukhuset and met with Dr. Åsa Carlsson Tedgren and PhD student Vaiva Kaveckyte. It is always valuable to meet with other research groups, both so that one has colleagues to reach out to for potential collaborations in the future, but I always notice (and I promise Shirin has not asked me to write this) how broad the research done at McGill is compared to other research groups which often focus more particularly on a single research topic.

I have attached some photos taken in Uppsala! Along with a weekend trip taken to Finland and Norway where Tristan and I passed through the arctic circle.







Un mois plus tard – One month later

Ça va bientôt faire un mois que je suis installé dans ma chambre dans les résidences étudiantes de Flogsta et je dois avouer que je n’ai pas vu le temps passer. Pour votre information, Flogsta est le quartier étudiant d’Uppsala, à quelques minutes à l’ouest du centre-ville. Nous sommes entourés par la nature ici et les couchers de soleil sont magnifiques du haut de mon immeuble. Le voisinage est bondé d’étudiants durant l’année scolaire, mais la plupart d’entre eux semblent avoir quitté la ville pour l’été. J’ai tout de même la chance de partager mon appartement avec mon colocataire Jonathan avec qui je passe mes soirées de temps à autre. [The english version follows]

[Quelques photos des résidences de Flogsta]

Je me sens bien ici. Je suis même prêt à dire que je m’y sens chez moi lorsque je rentre après une longue journée de travail. Une chose que j’apprécie particulièrement du quartier: Le fameux cri de Flogsta. À tous les soirs à 22h tapant, les étudiants ouvrent bien grand leurs fenêtres et crient à s’époumoner pendant un bref instant. La rumeur veut que ce soit pour se libérer du stress des études. J’y ai participé à quelques reprises, et je dois avouer que c’est drôlement libérateur !

Une autre chose que j’apprécie ici est que tout est à proximité, en passant par l’épicerie au coin de la rue jusqu’à la piscine où je m’entraîne parfois. En arrivant ici, Shirin m’avait dit que tout est à 15 minutes de vélo à Uppsala. Je confirme qu’elle disait vrai ! Je prends plaisir à me rendre au travail à bicyclette, en passant systématiquement près d’un petit chat noir étendu au soleil tous les matins. J’ai roulé un peu plus rapidement le vendredi 13 dernier.. par simple précaution !

Dans un autre ordre d’idées, je n’aurais jamais cru me baigner aussi fréquemment ici. La Suède étant plus au nord que Montréal, j’imaginais l’eau beaucoup plus froide qu’elle ne l’est en réalité. Par chance j’ai apporté mon maillot de bain ! Je me suis baigné dans la rivière Fyrisån au nord d’Uppsala, dans l’archipel de Göteborg avec ma bonne amie Caroline, et aux abords de la mer Baltique avec le groupe l’autre jour. Qui aurait dit que l’eau en Suède était aussi agréable? Il faut aussi dire qu’il fait très chaud ici depuis plusieurs semaines déjà. Les journaux locaux rapportent que le mois de juillet a été le plus chaud depuis au moins 260 ans. Cette chaleur intense est d’ailleurs à la source des feux qui ravagent les forêts à travers le pays en ce moment.

[Souvenirs de notre escapable au bord de la mer Baltique]

Parlant de ce soleil particulièrement intense, il ne se couche pas très longtemps ici. Au début de l’été, il se couchait aux alentours de minuit pour aussitôt se relever vers 3h30 du matin. Il m’a fallu une bonne semaine pour m’adapter à cette clarté nocturne, les rideaux de ma fenêtre étant très peu opaques. J’ai d’ailleurs ma petite idée là-dessus: les Suédois semblent faire le plein de luminosité durant l’été en prévision de leurs hivers froids et sombres. Comme tout, j’imagine qu’on s’habitue !

Malgré l’abondance du soleil, c’est sous une absurde pluie torrentielle que nous sommes allés pique-niquer à Ulva Kvarn dimanche dernier. En attendant que la pluie cesse, nous avons pris le temps de faire le tour des boutiques artisanales aux alentours. J’étais tout trempé en rentrant, mais j’ai passé un très bel après-midi en bonne compagnie !

[Pique-nique sous la pluie à Ulva Kvarn]


Almost a month has passed since I moved into my room in the Flogsta student residences and I must say: I have not seen time pass. For your information, Flogsta is the student district of Uppsala, a few minutes to the west of the city center. We are surrounded by nature here and sunsets are beautiful from the top of my building. The neighborhood is supposedly crowded with students during the school year, but most of them seem to have left the city for the summer. However, I have the chance of sharing my apartment with my roommate Jonathan with whom I spend my evenings from time to time.

Life is good here. I could even say that I feel at home when I come back after a long day of work. One thing I particularly like about the neighborhood is the infamous Flogsta scream. Every night at exactly 10 pm, the students open wide their windows and shout as loud as they can for a couple of seconds. Rumor has it that it is to free oneself from stress and anxiety. I tried a few times, and I must admit that it’s awfully liberating!

Another thing that I appreciate here is the proximity of everything around, from the grocery store to the pool where I train some days. When I arrived, Shirin said that one is 15 minutes away from anything when biking in Uppsala. I confirm she was right! I especially enjoy riding my bicycle on my way to work, passing by the same black cat lying in the sun at the exact same place every morning. I biked a little faster on Friday the 13.. you never know!

In another vein, I never thought I would swim so frequently here. Sweden being further north than Montreal, I imagined the water being much colder than it actually is. Luckily, I packed my swimsuit in my baggage! I went for a swim in the Fyrisån River in Uppsala, in the Göteborg Archipelago with my good friend Caroline, and even in the Baltic Sea with the group the other day. Who would have thought that the water in Sweden is so pleasant? Also, it has been very warm around here recently. Local newspapers reported that the month of July was the hottest in at least 260 years. This intense heat is also causing big fires at the moment, ravaging forests all across the country.

Speaking of the sun, it does not set for very long at night. When we arrived a month ago, it would go down around midnight to get right back up as early as 3:30 in the morning. I needed a whole week to adapt to these bright Swedish nights, mostly because of the very thin curtains on my window. I have my little idea about this: I believe Swedes get the most out of the sun during summer,  in anticipation of their cold, dark winters. Just like everything else, I believe you get used to it!

Despite the abundance of sun of the past few weeks, it was under an absurd torrential rain that we had a picnic in Ulva Kvarn last Sunday. While waiting for the rain to stop, we took some time to visit the craft shops all around. I was totally soaked when I got home, but I had a great time with great people!


Un accueil chaleureux – A warm welcome

Bonjour, mon nom est Julien Mégrourèche et je suis un candidat à la maîtrise en physique médicale sous la supervision de Dre Shirin Enger. The english version follows.En collaboration avec Lilian Childress et Jack Sankey du département de physique de l’Université McGill, nous développons un dosimètre in-vivo innovant.

Depuis notre arrivée à Uppsala, nous sommes installés dans les bureaux de l’unité de Sjukhusfysik (physique hospitalière) du centre hospitalier Uppsala Akademiska Sjukhuset. Il est peu dire que nous sommes bien accueillis ici, notamment par le professeur Anders Ahnesjö et par le bon café de la machine départementale. Nous avons d’ailleurs eu le privilège de visiter diverses cliniques et laboratoires à travers nos rencontres de la semaine dernière.

Mardi, nous avons tout d’abord visité la clinique de radiothérapie, accompagnés par Eric Grönlund, un sympathique candidat au doctorat et physicien médical à temps partiel ici à l’hôpital. À ma grande surprise, la clinique est plutôt similaire à celles que je connais au Québec. Elle comprend 4 accélérateurs linéaires, une suite de Curiethérapie et une dizaine de physiciens motivés qui ont sensiblement le même rôle que nos physiciens québécois : s’assurer que la bonne dose soit délivrée au bon endroit. Au printemps prochain, il est prévu que la clinique déménage dans un nouveau centre flambant neuf, à la fine pointe de la technologie. Elle sera notamment équipée d’un MR-Linac, ce qui s’annonce particulièrement excitant !

Le lendemain, le généreux Filip Heijkenskjöld, professeur à l’Université d’Uppsala, nous a offert de visiter le laboratoire Ångström. Nous y avons découvert le département de physique en passant notamment par les salles de classe des étudiants. Comme en témoignent les photos ci-dessous, nous avons même eu droit à un tour de centrifugeuse dans un des laboratoires. Cœurs sensibles, s’abstenir!








Le même jour, Dr Erik Peterson nous a accueillis au laboratoire Tandem. On y retrouve de gigantesques accélérateurs de particules desquels émergent divers travaux de recherche allant de la caractérisation de matériaux jusqu’à l’archéologie, en passant par la biomédecine. Parmi leur différents projets, ils étudient notamment la neurogénèse du cerveau humain à l’aide de techniques de datation au C-14, ce qui m’a particulièrement fasciné. Ci-dessous se trouvent quelques photos de notre visite fort instructive.





Pour couronner le tout, nous avons visité la clinique Skandion, soit l’impressionnant centre de proton thérapie sur le campus. Erik Almhagen, lui aussi candidat au doctorat et physicien médical à temps partiel, nous a invités à parcourir la clinique qui n’est d’ailleurs ouverte que depuis quelques années. Elle comprend 2 salles de traitement en fonction et les physiciens du centre ne chôment pas : leur charge de travail est particulièrement importante en raison de la complexité de l’équipement. De toute la visite, c’est la taille surréaliste des appareils qui m’a le plus surpris de par leur hauteur de presque 3 étages. Heureusement, ils ont pensé à tout : la majeure partie de l’appareil n’est pas à la vue des patients afin de ne pas les angoisser inutilement.









Somme toute, c’est un accueil bien chaleureux auquel nous avons eu droit à Uppsala jusqu’à présent. Il ne reste plus qu’à espérer que les prochaines semaines soient toutes aussi formatrices, ponctuées de rencontres enrichissantes. Personnellement, je suis certain qu’elles le seront !


Hi, my name is Julien Mégrourèche and I am a MSc candidate in medical physics under the supervision of Dre Shirin Enger. In close collaboration with Lilian Childress and Jack Sankey from the physics department of McGill University, we are developing an innovative in-vivo dosimeter.

Since our arrival in Uppsala, we are installed in the offices at the Sjukhusfysik unit at the Uppsala Akademiska Sjukhuset. Medical physics is called “hospital physics” in Sweden. We were warmly welcomed here, especially by Professor Anders Ahnesjö and by the coffee machine at the department. Over the last week, we had the chance to visit various clinics and laboratories in Uppsala with interesting people.

On Tuesday, we first visited the radiotherapy clinic with Eric Grönlund, a sympathetic PhD candidate and part-time medical physicist here at the hospital. To my surprise, the clinic was quite similar to the ones I know in Montreal. It comprises 4 linear accelerators, a brachytherapy suite and about 10 motivated medical physicists that have essentially the same role as our Québec physicists: To ensure that the right dose is delivered at the right place. Next spring, the clinic is expected to move into a brand new, state-of-the-art building. It will be equipped with an MR-Linac, which promises to be particularly exciting!

The next day, the generous Filip Heijkenskjöld, professor at Uppsala University, offered to visit the Ångström laboratory. We had a tour of the physics department, including the student classrooms. As you can see on the pictures above, we even had a centrifuge ride which was very dizzying. The centrifuge is used for undergraduate mechanics labs.

On the same day, Dr Erik Peterson welcomed us to the Tandem laboratory where we discovered gigantic particle accelerators used in a broad range of research fields including material characterization, archeology and biomedicine. Among their various projects, they study the neurogenesis of the human brain using C-14 dating techniques, which fascinated me. Have a look at the pictures from our highly informative visit.

Finally, we visited the Skandion clinic, the impressive proton therapy center on the campus. Erik Almhagen, also a PhD candidate and part-time medical physicist, invited us to visit the clinic which has only been open for a few years. It comprises 2 functional treatment rooms and the physicists workload is particularly important because of the complexity of the equipment. Of the entire facility, the surreal size of the gantries surprised me the most by their height of almost 3 floors. Fortunately, they thought of everything: Only a small part of the machine is visible to patients so as not to worry them unnecessarily.

All in all, we had a warm welcome in Uppsala so far. Let’s now hope that the next weeks will all be as enlightening, filled with enriching encounters. Personally, I’m sure it will be!


Arrivée à Uppsala / Arrival In Uppsala

Bonjour à tous, je suis Tristan Shoemaker, un candidat BSc en Majeure Physique et Mineure Informatique travaillant avec Dre. Shirin Enger cet été. The English version follows.

Ça fait seulement quelques jours que nous sommes là à Uppsala, mais déjà un rythme de vie a commencé. Mardi dernier, le 3 juillet, nous sommes arrivés fatigués mais prêts à commencer à travailler. Je continue à améliorer la dosimétrie de curiethérapie pour plusieurs sites tumoraux. Pendant mon séjour à Uppsala, je vais travailler en collaboration avec le professeur Anders Ahnesjö pour améliorer la dosimétrie pour le traitement de curiethérapie du cancer de la prostate. Comme le travail que nous faisons est essentiellement le même, ça contribue à nous transporter en douceur dans ce nouvel endroit. Au cours de ce premier week-end, j’ai presque l’impression d’être déjà là depuis plusieurs semaines. Parfois j’oublie que je suis en Suède jusqu’à je trouve une petite différence. Les pistes cyclables sont sur les trottoirs, pas sur la route. La cuisinière a une minuterie pour éteindre les plaques chauffantes. Les prises électriques sont différentes. Bien sûr, les panneaux et les gens parlent suédois! Je pense que cela représente comment la physique est la physique, peu importe où ça se fait.

L’été à Uppsala semble être plus lent que pendant l’hiver dans la région où j’habite. En entrant dans le centre-ville (Uppsala Centrum) , il y a soudainement une explosion de vie. La ville est soigneusement divisée en différents quartiers qui semblent avoir chacun leur propre texture, style architectural et identité. J’espère pouvoir les explorer tous pendant mon séjour.


Hello all, I am Tristan Shoemaker a BSc candidate in Majors Physics and Minor Computer Science working with Dr. Shirin Enger this summer.

It has only been a handful of days since we have arrived in Uppsala, but already a rhythm of life has begun. Last Tuesday, the 3rd of July, we arrived tired but ready to begin working. I am continuing on an improvement of brachytherapy dosimetry for several tumour sites. While in Uppsala I will work closely with Prof. Anders Ahnesjö to improve the dosimetry for brachytherapy treatment of prostate cancer. As the work we have been doing has been mostly the same it has helped to carry us smoothly into this new place. During this first weekend, I feel almost like I have already been here for a few weeks. Sometimes I forget I am in Sweden until I find a small difference. The bike paths are on the sidewalks, not the road. The stove has a timer to activate the elements. The electrical plugs are different. Of course, the signs and the people speak Swedish! I think this represents how physics is physics, no matter where it is being done.

Summer in Uppsala seems to be sleepier than during the winter when the students are here in the area where I am living. Going into the city center (Uppsala Centrum) however, there is suddenly an explosion of people. The city is neatly divided into different neighbourhoods which seem to each have their own texture, architectural style and identity of people. I hope to be able to explore all of them during my stay.

Tristan Shoemaker

Coopération Québec-Conseil Nordique des Ministres – Collaboration between Quebec-Nordic Countries

Au cours de l’été 2018, moi et quatre de mes étudiants Tristan Shoemaker, Joseph DeCunha, Liam Carroll et Julien Mégrourèche visitent la Suède pour deux mois de collaboration de recherche à l’aide des fonds partiellement fournis par la Coopération Québec-Conseil Nordique des Ministres. Les étudiants effectueront des recherches à l’Université d’Uppsala et effectueront des stages dans des entreprises suédoises dans le domaine de la radiothérapie. Pendant notre séjour en Suède, nous publierons un blog sur notre collaboration et nos expériences de recherche.

During summer of 2018, I and four of my students are visiting Sweden for two months research collaboration through funds partly provided by Coopération Québec-Conseil Nordique des Ministers. The students will conduct research at Uppsala University and internships at Swedish companies in the field of radiation therapy. During our time in Sweden, we will blog about our research collaboration and experiences.

When approximations aren’t enough – Limitations with intravascular brachytherapy

Not only has the time for personalized treatment of cardiovascular disease arrived but patient outcomes have been put in jeopardy when patient specific anatomy is not considered.

The future of medicine is in screening, prediction, early diagnosis and individually tailored treatments including post-treatment follow-up, i.e. in personalised medicine. A recent editorial in Nature Medicine discusses the scarcity of personalized medicine for treatment of cardiovascular disease while it has revolutionized cancer therapy [1]. In radiation therapy specifically, clinical research and technological advances in imaging and radiation delivery systems have enabled the capability to personalize treatments for accurate delivery of radiation dose to the tumours and limiting dose to nearby radiation sensitive healthy tissues based on clinical parameters and patient-specific anatomical information.

Due to recent insights in disease mechanisms and emerging treatment strategies, the time is opportune to develop personalized treatments for cardiovascular disease. Introducing personalized medicine for cardiovascular disease should not only be pursued as a means of improving outcomes and identifying novel treatment strategies, it must be pursued to ensure that existing treatments are appropriate and will be effective. There exists a modality of treatment for cardiovascular disease for which the absence of patient specific information is not only a disadvantage but may actually hinder successful treatment. Intravascular Brachytherapy (IVBT) is a form of radiation therapy used to treat in-stent restenosis (ISR). After the advent of the bare-metal stents in the 1990s, a new difficulty arose when sites initially treated with a stent became re-stenoted in the months following initial treatment. IVBT involves applying a dose of ionizing radiation to the arterial walls immediately after stent implantation to destroy neointimal tissue which may proliferate and lead to ISR.

It is well known that if an inadequate dose of radiation is delivered to the target area, or if the size of the target area is underestimated, the treatments may fail, and patient outcomes will be jeopardized [2]. Early attempts to implement IVBT involved coating stents with beta emitting radioactive isotopes. Treated arteries became re-stenoted on each side of the radioactive stent where the radiation dose fell off due to insufficient coverage of the radioactive isotope at the stent ends. This side effect lead to the development of catheter-based devices, where beta emitting radioactive sources (radioactive seeds) are guided temporarily to the stented site (dwell position) immediately after stent implantation and kept at the site for a certain amount of time (dwell time) until an adequate dose is delivered.

Compared to other forms of radiation therapy, treatment planning in IVBT is archaic. It consists of an estimation of the patient’s artery diameter by visual inspection under fluoroscopy and then referring to a reference sheet which lists the dwell times for different vessel diameters. This method of treatment planning assumes that the patient’s artery is a perfect cylinder, that the radioactive seeds are centered in the cylinder, and that all tissue and materials surrounding the treatment site are water equivalent.

With the advantage of modern software and computing capabilities, we have been able to revisit the underlying assumptions of IVBT. In a tank of water (which serves as a crude approximation for patient tissue), the range of beta particles from the isotopes used in IVBT is about 2 mm, which corresponds to the distance from the surface of the radioactive seed to the target region. In the water-equivalent approximation, the target region receives the prescribed dose of radiation. In a real-world delivery, the beta particles interact and are absorbed by non-water equivalent materials such as the metallic cardiac guide wire, the stent and calcifications as well as patient tissue. Recent work indicates that the cardiac guidewire used to guide the radioactive seeds to the treatment site blocks the ionizing radiation and can cause dose reductions as high as 48% in regions behind the guidewire alone [3] [4]. When the presence of arterial stent struts and calcified plaques are considered, the dose of radiation can be reduced by more than 60% in localized regions. The target volume is behind these heavily attenuating media and will not receive the prescribed dose, i.e. the delivered dose will be much less than the prescribed dose.

This all might seem inconsequential if IVBT weren’t undergoing a small revival. The use of IVBT was reduced due to the advent and adoption of drug-eluting stents (DES) in the early 2000s. However, a need for IVBT still exists. Patients treated with DES require coronary reintervention [5]. The typical modality of treatment for patients whose DES failed is to insert another DES at the initial site of stent failure. For a group of patients with multiple DES implemented at the same site IVBT has been shown to be a safe and effective treatment [6]. A need for IVBT is still being communicated by cardiologists; a 2016 editorial in the Journal of the American College of Cardiology calls for IVBT to be considered for patients with DES failure [7].

The world of medical physics can at times be separated from the world of physicians. There isn’t always adequate knowledge exchange between medical physicists and their colleagues; the concerns of physicists can seem technical and out of touch with the concerns of practitioners. This is one instance where it is important physicians have at least a rudimentary understanding of the physics underlying a treatment modality so that it can inform their practice. Cardiologists should be wary of applying current IVBT technology when they have reason to believe that large calcified plaques exist at the treatment site or multiple stents have been previously implanted, as the dense bulk material serves to block ionizing radiation from reaching the target neointimal tissue; both of these factors may be contraindications for IVBT.

If IVBT is going to see continued use, the medical community owes it to patients to ensure that device manufacturers modernize their devices and seek out solutions to the real and significant problems that have been identified with IVBT products, otherwise manufacturers will continue to produce the same IVBT devices which have been on the market for more than 15 years now. We have suggested solutions to improve current IVBT delivery systems and dosimetry [3] [4] but only if the cardiology community is informed and insists that devices allow for patient specific treatment planning, will manufacturers make meaningful changes to their products. The reluctance and concerns of a small group of informed medical physicists is not enough to prompt any change in the current practice of IVBT.

Written by Joseph DeCunha and Shirin A. Enger

[1] Nature Medicine Editorial Board. Taking personalized medicine to heart. Nature Medicine 2018; 24:113.

[2] van der Giessen WJ, Regar E, Harteveld MS, et al. “Edge Effect” of 32-P Radioactive Stents is Caused by the Combination of Chronic Stent Injury and Radioactive Dose Falloff. Circulation 2001; 104:2236-2214.

[3] DeCunha J, Janicki C, Enger S.A. A retrospective analysis of catheter-based sources in intravascular brachytherapy. Brachytherapy 2017; 16:586-596.

[4] DeCunha J, Enger S.A. A new delivery system to resolve dosimetric issues in intravascular brachytherapy. Brachyherapy 2018; article in press.

[5] Ohri N, Sharma S, Kini A, et al. Intracoronary brachytherapy for in-stent restenosis of drug-eluting stents. Adv

Overcoming Nobel Prejudice: Story of Lise Meitner and Nuclear Fission


Nuclear fission is one of the most important discoveries of the 20th century. Yet not many know that it was Lise Meitner who was behind the discovery, just after her escape from Nazi Germany to Sweden in 1938. In 1944 Otto Hahn, Lise Meitner’s laboratory partner of thirty years, who remained in Berlin throughout the Third Reich, was awarded the Nobel Prize for Chemistry. The separation of the former collaborators and Meitner’s exile in Sweden led to the Nobel committee’s failure to understand her part in the work. The Nobel committee’s mistake was never acknowledged, but was partly rectified in 1966, when Hahn, Meitner, and Strassmann were awarded the United States Fermi Prize. She was also awarded numerous prizes and honorary doctorates by universities in the United States and Europe.

Who was Lise Meitner?

Lise Meitner was born in 1878 as the third of eight children of a Viennese Jewish family. She showed an early talent for mathematics and was privately tutored. Her father insisted that each of his daughters should receive the same education as his sons. Due to Austrian restrictions on female education, she entered the University of Vienna in 1901, at an age of 23. She was the first woman admitted to the university’s physics lectures and laboratories. With Ludwig Boltzmann as her teacher, she came to the conclusion that physics was her calling and earned a doctoral degree in physics in 1905. Three of her sisters also earned Ph.D. degrees later.

Meitner was invited to Berlin by Max Planck to continue with her post-doctoral studies. From 1907–1912 Meitner worked as an unpaid research scientist at the Berlin Institute for Chemistry but was not permitted access to the laboratories since women were prohibited entry to the institute. During this time she met the radio-chemist Otto Hahn, who became a thirty-year research partner in experimental work discovering new radioactive elements and unraveling their complex physical properties.

After World War I Otto Hahn was named the administrative director of the Kaiser Wilhelm Institute for Chemistry, while Meitner supervised the Physics Section, which she led successfully for over twenty years until forced to flee Berlin under the Third Reich. Meitner became an official University Lecturer in 1922, but even in liberalizing Berlin the press jokingly reported the topic of her inaugural speech as “Cosmetic Physics” instead of cosmic physics. In 1926 she was given the title of Professor.

From 1924 to 1934, the Meitner-Hahn team gained international prestige and were competing with the Paris team of the Irene Joliot-Curies and Rome’s Enrico Fermi to unravel the complexities of the mysterious “transuranic” elements. They were nominated for the Nobel Prize in Chemistry for ten consecutive years. They were also nominated for the Nobel Prize in Physics by Max Planck, Werner Heisenberg, Bohr and von Laue in 1936. Meitner was nominated for the Physics Prize three times by Niels Bohr after the World War II.

In 1938 when the National Socialists issued an order forbidding famous scientists to travel abroad, the international physics community under lead of Danish physicist Niels Bohr orchestrated Meitner’s escape route from Berlin. Her final destination was Stockholm, Sweden. Niels Bohr arranged work for Meitner at the new Nobel Research Institute of Physics under the leadership of Professor Manne Siegbahn, who won the Nobel Prize in Physics in 1924 for his discoveries in the field of X-ray spectroscopy. In Stockholm, Meitner lived on a meagre research assistant’s salary. She was neither asked to join Siegbahn’s group nor given the resources to form her own, she had laboratory space but no collaborators, equipment, or technical support, not even her own set of keys to the laboratory.According to some authors Siegbahn blocked Meitner’s research career in Sweden since he distrusted female scientists and he feared that Meitner, who was a brilliant physicist would outshine him with her ground-breaking research. Some physicist also later accused Sigebahn of having hindered her from receiving the Nobel price due to his extraordinary strong position in Swedish scientific community and membership of the Nobel committee.2

Meitner continued to exchange letters almost daily with Hahn. They met in Copenhagen in 1938 and planned new experiments. She urged him and their assistant Fritz Strassman in Berlin to continue research she had instigated on uranium. On December 24, she received a letter from Hahn recounting a strange “bursting” he described as occurring to uranium, forming barium. Hahn asked his trusted colleague to interpret this process: “What would physics say about such bursting?” He had written up their findings and submitted them to Die Naturwissenschaften on December 21 without crediting her contributions, and this act would literally eclipse Lise Meitner’s contributions to the discovery of nuclear fission in 1938.

Meitner and her nephew Otto Frisch, while hiking in the snowy Swedish woods, realized Bohr’s “liquid-drop” model of the atomic nucleus could explain the result mathematically. They scribbled formulas on a scrap of paper in the woods: A uranium atom could elongate when bombarded by neutrons, and occasionally some of the uranium atoms could split apart into two “smaller drops.” Frisch later dubbed this process “fission”, a term used by biologists to describe the elongated splitting of a cell. In fact, the uranium atoms in Hahn’s experiments had split to form the much lighter atoms barium and krypton, and ejected neutrons and a very large amount of energy, with a loss of some mass. Meitner was the first to realize Einstein’s famous equation E=mc2 was at play here, converting mass into energy. In January–March 1939, she wrote a series of articles to be published in Nature with Frisch on the nuclear fission of uranium.

In Sweden Meitner encountered concentration camp victims, which convinced her to never return to Germany, although in 1947 Hahn and Strassmann invited her to re-join them at the rebuilt Institute for Chemistry. She declined their invitation to form a new Max Planck Institute for Chemistry named after their mentor, and instead retired in Sweden on a small pension. Meitner spent most of her 70s and 80s traveling, encouraging female students to “remember that science can bring both joy and satisfaction to your life.” During her final years she lived close to her nephew Otto Frisch, in Cambridge, England, where she died on October 27, 1968.

  1. Lise Meitner: A Life in Physics, Ruth Lewin Sime, California Studies in the History of Science (11), 1997
  2. The Key to Nuclear Restraint: The Swedish Plans to Acquire Nuclear Weapons During the Cold War, Thomas Jonter, Palgrave Macmillan, 2016

Patient preferences and treatment choices for localized prostate cancer

After receiving cancer diagnosis, follows a chaotic time full of anxiety, fear and endless grief for the patients. Prostate cancer is the most common cancer amongst men in Canada and in the most cases it is diagnosed when it is still curable, nevertheless these men are faced with a long journey with many decision points along the road where they must manage their personal fear of a cancer death with the overwhelming thought of leaving their loved ones behind. In this state of mind, it is expected of the patients to get involved in the decision making process regarding their treatment.

Treatment options for localized prostate cancer are many, vary widely, and there is no consensus regarding the optimal treatment strategy. Ongoing research in the area of patients decision making and post intervention regret, reveals some insight in the patient’s choice of treatment option. Surgery is often preferred by patients seeking a cure, while brachytherapy is more often chosen by patients professing a desire for “the least invasive” treatment. Although patients stated that side effects are important, few patients report that side effect factors ultimately influence their treatment choice. However, there are several studies pointing out that men with prostate cancer often base treatment decisions on scientific misconceptions and anecdotal experiences of friends or family. Race/ethnicity and socioeconomic status plays a role as well.

Some studies show that the actual treatment choices bear little relation to the patient preferences, and instead show a strong association with clinician specialty. Physician’s advice depends heavily on the their specialty (radiation oncology vs. urology), as well as geographic region. In a recent study published in nature , researchers investigated the importance of physician’s attitudes about different treatments and the quality of life in prostate cancer, by performing a survey of specialists to assess treatment recommendations and perceptions of treatment related survival and quality of life. The conclusions from the study were that the radiation oncologists and urologists both prefer the treatment modalities they offer, perceive them to be more effective and to lead to a better quality of life. Patients receive biased information, and a truly informed consent process with shared decision making may be possible only if they are evaluated by both specialties before deciding upon a treatment course. In the absence of relevant randomized trials no decision regarding the superiority of any of the treatment modality can be made and the potential impacts of treatment side effects on quality of life for patients and their partners have to be considered in the informed decision making process.