Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
What GTV to CTV expansion do you use for limited stage small cell lung cancer with IMRT?
It seems to me that in stage III NSCLC cases, the CTV of the primary tumor in the lung and the CTV of the nodal volumes would be drawn differently for maximum efficiency: Primary: GTVp --> iGTVp --> + 5-7 mm = CTVp --> + 5 mm = PTVp Nodal: GTVn --> + 5-7 mm + entire nodal station (if desired) + el...
How you approach treatment of a glioblastoma in the setting of prior WBRT for a metastatic non-CNS malignancy?
I think treatment to 25 Gy in 5 fractions or 40 Gy in 15 fractions to areas of enhancement and/or post-op bed can be safely delivered after whole brain (assuming the patient was treated to 30 Gy in 10 fractions). We commonly treat with SRS after whole brain RT. Just be cognizant of cumulative dose t...
What dose should you treat the anal canal after excision of a T1 anal cancer with positive margins?
I would, under no circumstance, treat this patient to a dose of 50 Gy. For a T1 tumor (even unresected) that is likely an excessive dose. Keep in mind that the initial reports of RT and chemo used a dose of about 30 Gy with complete pathological response. There are data to suggest that doses of abou...
What is the best treatment for a squamous cell carcinoma of the palpebral conjunctiva with persistently positive margins after resection?
Ideally, would be managed by an Oncologist Ophthalmologist with high experience in ocular plaque brachytherapy. A "boomerang" plaque loaded with I-125 seeds calculated to the deepest margin (1, 2 mm deep, and 2-3 mm around the tumor or tumor bed). Total dose at the deepest point, 3,000 cGy. Jorge E....
How would you approach early stage unfavorable classical Hodgkin lymphoma with metabolic CR apart from a single residual positive node after 6 cycles of ABVD?
If a patient with early-stage, unfavorable HL had an excellent response to 6 cycles of ABVD, but had a single lymph node that only achieved a PR (Deauville 4), then there are two primary options.1. If you judge that the patient has achieved a reasonable response to chemotherapy, suggesting that syst...
What adjuvant therapy would you recommend for a T3N0, grade 3, undifferentiated sarcoma of the mandible with positive margins that is not amenable to re-resection?
From a radiation standpoint, I would offer adjuvant radiation therapy. Given positive margin, would image to make sure no gross disease. If microscopic positive margin, I would go to 66-70 Gy.
Do you consider adjuvant chemoradiation for resected pancreatic cancer with anterior surface “margin” positivity?
Whipple specimens are very difficult to process and evaluate. It requires collaboration between the surgeon and the pathologist to identify the relevant margins. I can't recall ever seeing this situation but it does not seem to me that the anterior peritoneal surface of the pancreas is a "true" marg...
In what circumstances would you recommend using DIBH in patients with breast cancer during an electron boost?
Sometimes use for breast boost for lower quadrant disease if exit beam is close to the heart to decrease heart dose.
What dose constraints for lung would you use in a patient with breast cancer requiring regional nodal irradiation who had significant pneumonitis during systemic therapy?
I would look into the absolute benefit of RNI in someone with significant pneumonitis as the downside may outweigh the benefit.
How do you manage severe fibrosis/contracture and breast/axilla pain in a patient with a history of breast radiation who cannot tolerate trental?
I have seen some patients with dramatic responses to pentoxifylline (Trental) and vitamin E, but the regimen needs to be continued for at least one year to prevent relapse (Delanian et al., PMID 12829674). However, this patient cannot tolerate Trental, so that is not feasible. Hyperbaric oxygen has ...