Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
What constraints do you use for SBRT near the renal vessels?
The FASTRACK II protocol (NCT02613819) prescribes 42 Gy in 3 fractions and does not have dose constraints for renal hilum/vascular trunk. I used Timmerman's constraint of 19.5 Gy for 15 cc and got away with a handful of patients.This QUANTEC paper in the red journal has a good discussion and data on...
How do you approach the adjuvant treatment of glioblastoma following up-front laser interstitial thermal therapy (LITT)?
This is an emerging area with very limited information; there are no large prospective trials to adequately answer the question. The issues faced by a Radiation Oncologist include: 1. Interpretation of the post-op scan: what is the true GTV? This remains unclear; we include all enhancing abnormality...
What is current practice for sparing a tissue strip in extremity radiation?
So far as I am aware, RTOG 0630 is the only source for a "skin strip" constraint, and as @Dr. First Last mentions, the protocol does not fully specify how this was defined. ("No more than 50% of a longitudinal stripe of skin and subcutaneous tissue of an extremity should receive 2000 cGy. This strip...
How do you treat elective neck regions in a patient with a second primary HN cancer and prior neck dissection and radiation?
Almost all re-irradiation trials and retrospective series have targeted the gross disease alone, without electively treating nodal basins. Even with this limited target volume, grade 4 toxicity is 20-30%, and treatment related deaths occur in 5-10% of patients. Locoregional control is only about 50%...
In what situations would you place a prophylactic trach prior to radiation for head and neck cancers?
In my practice, the decision on a prophylactic trach is made in a multidisciplinary setting in close coordination with my ENT colleagues. Generally speaking, we will consider placing a trach prior to treatment if there is a high concern for potential airway deterioration during radiotherapy. Clinica...
How would you manage a high grade primary mediastinal leiomyosarcoma status-post excision with negative margins?
There are scant data describing the role of adjuvant radiotherapy for mediastinal soft tissue sarcomas. The principles of managing sarcomas in other sites support post-operative radiotherapy following removal of a high grade lesion from a restricted anatomic space such as the mediastinum despite app...
Would you offer PMRT to a perimenopausal female with a single positive LN with microscopic ENE who has otherwise low risk features?
In this case, I would discuss the role of PMRT given her nodal involvement with microscopic ENE and being perimenopausal, despite having other low risk features. I would counsel the patient that the data suggests reductions in LRR with improvements in DFS, and DDFS though no clear survival advantage...
When using hypofractionated whole breast radiotherapy with a simultaneous integrated boost to the lumpectomy cavity, what IGRT strategy do you use?
My preference is CBCT daily and matched to clips/cavity. Our practice also does SGRT for all patients (tattoo-less clinic); however, that is not routinely reimbursed. If treating like RTOG 1005 (48/40 in 15 Fx) and approved for IMRT, will get approved for IGRT.
When treating with SBRT and immunotherapy for unresectable HCC, how do you sequence the treatment?
Great question. No great data in this space regarding optimal sequencing. In general, I would sequence SBRT first, followed by initiation of immunotherapy. Some data suggest that SBRT may best prime IO if administered prior to IO. Additionally, if the IO regimen preferred is atezolizumab/bevacizumab...
How would you evaluate the role for adjuvant radiation in a very young female (20s) with a localized vulvar SCC, HPV independent, status post hemivulvectomy?
Either re-excision or observation provided no dVin at margin and at least a 3 mm negative margin for invasive disease.