Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
What dose of radiation would you give for an orbital psuedotumor?
20 Gy/10 fractions.
What dose-fractionation would you utilize for an unresectable localized cutaneous melanoma that has progressed on immunotherapy?
If the concern is to minimize the chance of radiation-induced brachial plexopathy, then it is advisable to keep the equivalent total dose below the tolerance of the brachial plexus. The preceding immunotherapy is not known to change the risk of radiation-induced brachial plexopathy. Contrary to popu...
What is the risk that primary prostate radiotherapy will exacerbate levator syndrome or other chronic pelvic pain syndromes?
Presumably, dose to the levator ani would matter in this situation. One paper from U. of Groningen showed that V40 for levator ani was associated with increased stool frequency. There was no metric associated with rectal pain. However, it's an entirely different question for patients with preexistin...
How do you clearly communicate to parents that the main purpose of a phase I trial is to find the best dose of a new drug with the fewest side effects rather than treating the patient's cancer?
Just with any communication, check first to see what their understanding is. Then, see if they are ready to hear what you have to say. Say it and then have them repeat it. When discussing trials, this conversation occurs over more than once. At the first conversation, one may be trying to lay out op...
Which modality of RT is most appropriate for a patient with pT3N0(sn) endometrial cancer?
For T3b, I favor EBRT plus brachy as to target disease extending to parametria or vagina. For T3a with isolated adnexal involvement and favorable intrauterine factor, she would get chemotherapy for stage IIIA disease. In the past I used to offer EBRT after chemotherapy but now, if the patient is su...
What dose would you use for re-irradiation of metastatic melanoma to an inguinal node?
For melanoma, I have used 27 Gy in 3 fractions of 9 Gy, one week apart, for an unresectable tumor near the eye in an elderly patient. The patient was on concurrent nivolumab and remains NED 3 yrs out. I think that the inguinal area could tolerate this dose if it has been 6 months since prior course,...
In which clinical situations is there a good rationale for the use of proton therapy for GI cancers?
The biology of smaller fraction size is dominant with re-RT. Unless everything in the high dose volume (includes margin) can take that dose with low risk, smaller fraction sizes are preferred. IMRT allows more control of where the dose goes and better sparing of nearby sensitive organs than protons ...
Would you offer adjuvant RT for a small merkel cell carcinoma of the lateral canthus with a close margin?
Yes. The low rates of local recurrence after excision that I am familiar with are all after a "wide" excision is performed. In our institutional analyses that demonstrated a low rate of local recurrence after surgery without adjuvant radiotherapy to the site of the resected primary tumor, the median...
What is the role for adjuvant monoclonal antibody therapy with radiation for diffuse intrinsic pontine glioma?
There are several publications showing a small synergy when combining RT with immunotherapies—thought to be effective largely by the induction of a pro-inflammatory response.There are actually several different aspects to note for use of mAbs in the brain. The biggest argument you'll hear is likely ...
Would you recommend prophylactic cranial irradiation (PCI) for a teenager with a T cell acute lymphoblastic leukemia in remission?
No—modern systemic and CNS directed therapy is sufficient to mitigate the historic higher risk of CNS relapse (Vora et al., JCO 2016). While there is still a small risk of cranial relapse with modern systemic therapy, the improved success of response and risk adapted strategies utilizing varying deg...