Final Week of Radiation Oncology

The month on radiation oncology was excellent. 

Week 1: Dr. Tripuraneni – Learned about skin and prostate cancer treatment with radiation

Week 2: Dr. Lin – Learned about gynecologic and GI cancer treatment with radiation

Week 3: Dr. Chen – Learned about lung and CNS cancer treatment with radiation

Week 4: Dr. MacEwan and California Protons – learned about the benefits and downsides of radiation therapy

I have a much better sense now of what goes into planning radiation treatment for patients. Step 1 is a clinic evaluation to determine if the patient would benefit from radiation and to discuss the benefits and risks of treatment. Step 2 is a simulation visit where the patient comes for a CT scan that will be used by the radiation oncologist for contouring and treatment planning. Step 3 is contouring/planning and happens behind the scenes. The physician first draws in the targets based on the simulation scan. This can be fused with other imaging. Then the preliminary plan is sent to the dosimetrist and physicist to decide upon the best way to deliver the radiation to get to the treatment dose prescribed by the doctor while minimizing toxicity to surrounding tissues. This can take anywhere from a few days to two weeks depending on the complexity. Step 4 is when the physician reviews the final plan and submits it to the treatment machines. Step 5 is when the staff calls the patient to schedule him/her for treatment sessions. Step 6 is ultimately treatment which can be anywhere from a few days (in the case of palliative SBRT) to several weeks for fractionated photon therapy. In the past, I only saw the treatment phase and did not realize how much went into the evaluation and planning phase for each patient.

Last week I was at California Protons to learn about the benefits of proton therapy. The treatment facility was impressively large because it takes a lot more machinery to manipulate a particle beam. The benefits of protons are that they do not have an exit radiation dose. Instead, the energy deposits in the tumor and doesn't go beyond it, sometimes referred to as the Bragg-Peak. This allows the radiation oncologist to minimize off target radiation exposure. The downside is that the beam can be more intense for areas that are exposed, which can lead to weakening of bones and skin reactions. I think the experience broadened my appreciation of this technology and I can see it being of benefit to certain patients.

All-in-all I am very grateful for my experience in radiation oncology. Tomorrow I’ll head back to the oncology clinics. Mondays I’ll see gynecologic cancers in the morning, heme malignancies in the afternoon. Tuesday I’ll have fellow clinic. Wednesday I’ll be in breast clinic. Thursday I’ll be in breast/GU clinic in the morning and then GI/lung cancer clinic in the afternoon. This block has nearly two days for research time, which will give me time to get caught up on a few projects. I’ll also have my ASCO and ASH ITE exams this month to see how my knowledge base has improved since this time a year ago.