Radiation-Oncology: Day 1

I began my elective clerkship in Radiation-Oncology last week. This is definitely an area of medicine which we aren't taught much about while in medical school. I'll admit that I felt quite overwhelmed the first day; there are so many aspects of this branch of medicine which are simply overlooked during medical school. Honestly, I haven't had any sort of physics class since my Junior Year of Undergrad; at least we were required to have taken physics during our undergraduate years, before going to medical school, so that I do have some background in physics! I also have taken a lot of math courses through the years (and I'm actually fairly good at math considering I went into biology/chemistry/physiology and medicine!), which definitely helps to better understand physics...

Day 1: The morning was spent learning what the Radiation Technologists do, which includes friendly conversation with patients while they are properly positioned prior to the radiation treatment. On the patient's first day in the clinic, the techs and the physician select a position in which the patient will be during each following radiation treatment. They create a mold of the patient's legs so that the position of the legs is the same during each treatment. They place a small dot tattoo where the cross-hairs of different stationary lasers in the room meet, which allows them to ensure that the patient is in the proper position during each treatment (so that the radiation goes precisely where it is intended to go). For prostate cancer patients (and for a vaginal cancer patient), we also monitor the bowel and bladder positions prior to treatment. This is done by using an ultrasound machine to examine the expansion of the bladder and bowel. It's an important consideration because the prostate and vagina are quite mobile relative to the size of the bowel and bladder. Also, since the bowel and bladder cannot really tolerate the doses of radiation that we prescribe for the prostate, we need to ensure that the radiation beams are reaching their target (prostate) and not instead hitting another structure (such as the bowel or bladder). The techs are quite fast when it comes to placing the patients in the proper positions, and they are so good with the patients; they really bond with each patient, which makes the job so much more enjoyable. 

The afternoon was spent learning the basics about the medical physics behind radiation. I learned a bit about how using different sources as energy for radiation affects the penetration and preciseness of the beams (examples include photons versus protons versus electrons as a source). One of the PhD students went through the computer analyzing software that is used to determine the radiation fields and movement of the leaflets to obscure or enhance radiation to different areas, and how the Medical Physicists double-check to ensure that the algorithms produce the best treatment plan possible for each patient. 

There are different ways to go about administrating radiation, and there is a highly effective way to ensure that a vital structure which cannot tolerate much radiation (such as the spinal cord) does not get much of a dose while a near-by structure can still be treated with an optimal dose of radiation. This is accomplished by using what is called IMRT (Intensity Modulated Radiation Therapy). IMRT is really, really cool. It's nothing short of amazing to me, to be able to be so precise in administration of radiation so that the morbidity associated with radiation can be lessened. Other forms of external beam radiotherapy include: Conventional External Beam Radiation Therapy, and Stereotactic Radiation. Another form of radiation therapy, which is a targeted therapy, is called Brachytherapy. This involves the placement of a source of radiation inside of the body so that radiation can be administered to the desired area through the brachytherapy device. I have seen this technique used often in breast cancer and prostate cancer, but I have also seen it used to treat vaginal cancer. Another form of targeted radiation therapy is Radio-isotope therapy. This therapy involves administration of a radio-isotope through either infusion or ingestion, and the chemical properties allow the material to be taken up by selected cells. This therapy is most often used in the treatment of thyroid cancer and bone metastases. 

The guys (and one girl!) in the medical physics program are incredibly smart. They greatly enhance patient-care by acting as another safety guard against morbidity and mortality associated with high-dose radiation. I'm also quite impressed by their knowledge of anatomy. They are yet another example of the importance of integrated teamwork to ensure the best outcomes for our patients.

I went home after my first day on Radiation-Oncology and read for hours about different radiation techniques and the physics behind radiation, feeling quite overwhelmed by the physics and mechanisms of treatment which correspond with radiation therapy. This clerkship will be quite useful for me as a future oncologist, so that I will better understand what my patients will be going through while in the care of a referred Radiation-Oncologist.