Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
What elective lymph node areas do you cover for T4a rectal adenocarcinoma?
Here's my take: I think the spirit of this convention is really that involvement of more anterior organs raises the risk of external lymph node chain involvement. Visceral peritoneal involvement is certainly a marker for a more aggressive disease and certainly may also mean that the cancer involves ...
Would the presence of diverticulosis change your dose constraint for large bowel?
I have not changed the dose constraint for large bowel with or without diverticulosis. I use 0.5 cc to 33 Gy as my dose constraint, and I would make sure the 'tics are included in the colon volume.
Do you offer consolidation RT to the prostate in patients with extensive stage small cell carcinoma of the prostate after PR to chemotherapy?
Generally, no, unless there is a compelling case for local control to avoid symptoms.I suppose the rationale in favor would be extrapolating from thoracic RT for extensive stage SCLC, but that is probably a stretch. The dose in that argument would be relatively low (30 Gy / 10 fractions, as in CREST...
How do you approach treatment of an IDH wild-type low-grade astrocytoma in an elderly patient?
Inherent in this good question are really two separate issues: 1) how to approach IDH-wt LGG and 2) how to treat glioma in the elderly (and/or frail).The first issue is addressed by the recent cIMPACT-NOW update #3 which states that in the presence of an IDH-wt gr 2-3 glioma, the presence of one of ...
What dose-fractionation would you utilize to palliate a symptomatic distal rectal cancer in an inoperable elderly gentleman with previous prostate bed radiation therapy 30 years prior?
First, I think we should all remember that the incidence of rectal cancer is about doubled after prostate RT. That would generally not influence my decisions about using RT for prostate cancer, but we should keep this in mind (and inform the patient). The decision about palliative RT is heavily depe...
What is your preferred regimen for HDR monotherapy in the treatment of low and favorable intermediate prostate cancers?
At UCLA, we now use 13.5 Gy x 2 fractions for most cases. The two implants are done 4-7 days apart (some cases are Monday and Friday). We also use this program for some favorable high-risk-group patients.@Dr. First Last (brachytherapy division director) uses slightly different dose constraints. Salv...
Would you treat a localized radiographic prostate failure after EBRT with HDR brachytherapy?
I agree that a biopsy is needed and that you can't just rely on suspicious imaging findings. mp-MRI can underestimate the true extent of disease and is not 100% specific. Also if one is considering focal salvage, tt is critical to understand the full extent of recurrent disease. There are multiple s...
Do you omit seminal vesicle radiation if MRI is negative for SVI?
No. MRI has excellent specificity (>95%) for seminal vesicle invasion, but much less impressive sensitivity (<60%). See de Rooij et al. European Urology 2016 (PMID: 26215604) for a meta-analysis and a nice study by Soylu et al. Radiology 2013 (PMID: 23440325 PMCID: PMC6940014). So, MRI can be very u...
How would you manage locally advanced head and neck patients getting definitive chemoradiation who show progression halfway through treatment?
I have seen this twice within the last year. Here is what we did: 1) First patient had high risk cutaneous SCC s/p WLE and neck dissection. He progressed in the skin after surgery when seen for sim, and continued to progress during first week of RT. We stopped RT, started cemiplimab. He had a remark...
How would you manage initially unresectable node-negative pancreatic adenocarcinoma that after upfront chemotherapy achieves a complete radiographic response on interval MRI and CT?
This is an interesting question and, in my experience, something that is not commonly encountered clinically. I will assume here that the patient has no visible sites of disease elsewhere. Still, given that scans are a poor predictor for pathologic response and complete response in pancreatic cancer...