Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
What is the optimal dose and fractionation of RT for a T2N0 laryngeal SCC?
Great question. The data for accelerated fractionation (AFX) vs. hyperfractionation (HFX) vs. standard fractionation for T2 is a bit difficult to parse.At a basic level, we all recognize that T2 larynx spans a range from pts just a bit larger than T1 TVC cases, who could expect >90% survival with RT...
How much subglottic extension from a primary glottic tumor would make you treat the regional lymph nodes?
This is a question that may be more complicated than it looks, though I recognize that Dr. @Dr. First Last has a wealth of experience in this area. The first issue is that the definition of the cranial extent of the subglottic region is not standardized. It can vary from just under the cord to 5 mm ...
Is there a role for a post-operative boost in a patient with rectal cancer who has a positive margin after total neoadjuvant chemo and chemoradiation therapy?
As is usually the case with questions of this sort there is not just a yes or no answer. First, we rarely use a postop boost as if we have concerns about the circumferential margin on our initial evaluation, we set up the patient for intraoperative RT. IORT has big advantages in giving a very high l...
Do you recommend a waiting period to conceive after prostate radiation?
Yes, I typically advise that men and their partner use contraception for at least 3-4 months after the last fraction of radiotherapy based on the fact that the maturation cycle of sperm is estimated at approximately 2- 2.5 months. I typically counsel men prior to treatment that there is a chance (bu...
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...
How do you sequence hypofractionated radiation and systemic therapy for patients with unresectable cholangiocarcinoma?
I have generally cared for patients analogously to that done in the initial NRG GI001 or ABC07 trial designs with the use of initial systemic therapy for 3-6 months followed by consolidative RT targeting a BED > 80.5, assuming a/b ratio of 10 Gy. Tao et al., PMID 26503201 In my practice, it’s most c...
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...