Second day - doesn't count

Ok - I sit down in the waiting area and two minutes later a maybe 25-30 year old operator sits down next to me and explains that the system crashed. "Unfortunately we can't do any radiation today. The technicians are on their way. We've spoken to Prof. Glanzmann and he proposed to do two sessions in one day next week.."

Wait a second. This isn't enough information - it might be routine for you but I need more details to feel comfortable. After making my point and asking to speak to Prof. Glanzmann it takes them a few minutes. Finally I have the chance to get more details.

How many times do these systems fail? Turns out a few times a year at least. Usually it's the mechanical part that controls the radiation field. This is done with many little lead pins (picture). Each of them supposedly has it's own motor and.. ..  well you get the picture one of the motors had an issue.

What happens if you can't do a session - do you just continue the next day and add one at the end? Not really - it seems to be important that the entire therapy is completed within a given timeframe. Instead of adding another day at the end they want to do two sessions in one day. The sessions need to be at least 6 hours apart. In rare cases 4 hours would work too. 

I've been told, that they are using 2.12 units per session for my therapy. This is a slight acceleration over the standard of 2 units per session and I've also learned that I'll do 33 sessions. Initially I was told 30 sessions. 

Why is it important to not have bigger breaks between radiation sessions? It looks like healthy cells don't really benefit from longer recovery time but tumor cells benefit from longer breaks. They seem to become more active during longer breaks. This doesn't make too much sense to me and my doctor couldn't really give me much more details. He said the phenomena isn't understood well. He also says it's only proven in a microscopic environment. 

Can you control the effectiveness of the therapy in the middle by doing a CT to see if the tumor shrinks?  This isn't really to relevant for me since we have removed the primary tumor prior to this therapy with surgery. While doing the planning CT they have discovered suspicious lymph nodes. So I was thinking when we are half way through the therapy we could take a look if the lymph nodes are still suspicious. The issue is that you can't assume the tumor shrinks linear while doing radiation. The radiation changes the DNA of the tumor cells but as long the cells are not splitting nothing visible will change. Whether the radiation is having a positive impact or not can only be seen when the tumor cells are splitting. More active tumors split cells faster. Overall it means, that even if the tumor isn't shrinking while you are half way through with your therapy, radiation still might be effective. Obviously if the tumor is shrinking, you know that your therapy is working (at least a bit).

Even at the end of the therapy there might still be tumor cells around but they could go away again once they are splitting. 

I don't know if there is a way to enforce the splitting or if it can be made faster. I also don't know if DNA samples are being taken from time to time for research purpose. Would be interesting to know. 

I wasn't very happy how the radio-ontology department was communicating so far but they are more than willing to answer any questions that I have. The issue is just  that without some background details my questions are dull. I depend on an active communication - more like a push so I can start to pull information. 

After all the talk I've managed to squeeze the lost day into a Saturday session - usually they don't do Saturdays.