Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
How would you treat an early-stage gastric adenocarcinoma in a patient who is medically inoperable and not fit enough for chemotherapy?
In my n=1 experience, I treated a medically inoperable patient with a T1N0M0 gastric body adenocarcinoma with "definitive" RT with mild Xeloda. I had the gastroenterologist place clips around the tumor. I treated the whole empty stomach and lymphatics to 45Gy and the gross disease to 54Gy. The patie...
How do you define close and negative margins for soft tissue sarcoma?
The paper by Gundel et al, “Analysis of margin classification systems for assessing the risk of local recurrence after soft tissue sarcoma resectionâ€, J Clin Oncol, 2018 provides useful data regarding the predictive power of different margin classification systems for extremity and truncal soft ...
How do you manage unresctable thoracic esophageal cancer invading the trachea?
I treat these cancers with chemoradiation therapy. That is, I don't forego treatment for fear of creating a fistula where there wasn't one before. Stabilization of the airway is important and should be established before starting treatment and reassessed throughout. If there is a pre-existing fistul...
What dose fractionation schedule do you use to treat head and neck cancer in a patient with Fanconi's Anemia?
If p16 positive oropharynx, 1.2 Gy bid to 64.8 Gy. Otherwise 74.4. Probably no chemo.
What is the best test to determine HPV status for SCC?
Good question. According to the new (8th) edition of the AJCC staging manual, and ACP, they recommend that you initially test for p16 only, for it is a good surrogate marker for HPV involvement. Further, as I recall, HPV testing maybe done if you suspect it is a negative p16 result, for example. Tha...
What constraints do you use for the normal brain when treating large CNS tumors with standard fractionation?
With photon therapy, we use guidance (not absolute), using the following principles, when using 1.8 to 2 Gy per fraction: Lenses max dose 7-10Gy Optic Chiasm and optic nerves max dose < 60Gy without chemotherapy and 56Gy with chemotherapy. Retina max dose < 50Gy without chemotherapy and 45Gy...
Do you routinely use PRVs for CNS planning?
We do not use PRVs specifically for primary CNS planning or for brain mets treated with Gamma Knife. We have PRV constraints for Spine SRS specifically for the spine.
Do you routinely use any type of motion management or breathing techniques when treating a lower esophageal cancer?
I obtain a 4DCT scan at simulation with free breathing. I do not use abdominal compression, gating, or other motion management techniques. There is certainly room for more data here to fully evaluate the potential value of these techniques. But for now, I don't use them in this situation. In my expe...
Is there any upper limit of volume or shape of a prostate gland which would be a red flag to cytoreduce prior to treatment?
Astro/aua consensus guidelines based on published data limits to 100cc or less
How would you manage an elderly patient with metastatic breast cancer with locally advanced bilateral primaries?
It depends on symptoms. If no impeding skin breakdown, ulceration or pain/lymphedema, I will see how they respond on endocrine therapy. If symptomatic, I will consider 30 Gy/10 fx using opposed tangents or in some cases with rapidly progressive disease 20 Gy/5 fx