Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
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...
How would you manage a treatment interruption during SBRT to the liver?
The answer to this question is "it depends". Given that the original delivery of SBRT was two fractions per week over a period of 2.5-3 weeks for 3-5 fractions, if the patient completes SBRT within this time frame, it would still not truly qualify as a treatment interruption.Further, if you deliver ...
Do you adjust PSA for finasteride use when determining prostate cancer stage and risk category?
We generally use the rule of 50% (real PSA is twice the lab value when on Finasteride).
Do you offer radiation therapy for locally advanced, node positive rectal adenocarcinoma in patients with Li-Fraumeni syndrome?
The only thing that is clear is that patients with LFS have an increased risk of secondary malignancies secondary to ionizing radiation. The risk is as high or higher than the absolute risk reduction of local tumor recurrence. For this reason, elective radiation is a relative contradiction. In LARC,...
What margins do you use for hypofractionated treatment of glioblastoma?
Since I am generally using hypofractionated treatment in elderly, unresectable, or poor performance status patients, I tend to favor smaller margins to minimize the risk of toxicity. The largest I would use is edema +1cm for a small tumor with minimal edema. For a large tumor with extensive edema, I...
Will you be recommending relugolix due to rapid suppression of testosterone and lower risk of cardiovascular events?
Once FDA approved, it will be an option; but I'm not sure what the cost to the patient will be, as it is an oral drug and that may be a limiting factor.