Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
When re-irradiating the spinal cord, what do you use as a guideline for the interval between treatment and the amount of tolerance theoretically "regained"?
Perhaps the most commonly used estimate is that the spinal cord “heals” 25% of the previously delivered dose six months after completing radiation. While this statement didn’t originate with the QUANTEC paper by Kirkpatrick et al. on the subject, it is explicitly stated there, and the paper is a goo...
What is the treatment volume for primary breast lymphoma?
This is a rare presentation for DLBCL. In most instances tumor fairly small and lumpectomy can be performed and usually has been before dx is established. Post chemo I usually rx whole breast to 30gy. One could argue against RT theoretically if lumpectomy with neg margins has been performed but it i...
When do you recommend consolidative XRT for patients with advanced stage (III-IV) DLBCL who achieve CR to chemoimmunotherapy?
The cornerstone of therapy for advanced DLBCL is chemoimmunotherapy (R-CHOP). Efforts to improve upon this with systemic therapy have been largely unsuccessful (dose-dense chemotherapy, maintenance R, more intensive chemotherapy, high-dose chemotherapy and autologous SCT, etc.). There are increasing...
What role does external beam radiotherapy play in the treatment of well differentiated papillary thyroid cancer when a total thyroidectomy and lymph node dissection cannot be performed?
Following a partial thyroidectomy (meaning less than a near-total extirpation and gross residual disease), the role of RAI is unproven and the likelihood of morbidity is real. In terms of XRT, and in a patient with reasonable co-morbidities, I would offer XRT to 60-66 Gy. Keep an eye on spinal cord ...
For a GE junction tumor with a lymph node distant from the primary site, would the treatment volume be contiguous?
In general, a LN metastasis more cephalad to the primary GEJ tumor should be included as one contiguous volume with the primary tumor CTV. The rationale for this approach is that the lymphatic system of the esophagus is directly within the wall of the esophagus, so a LN metastases can skip up the es...
When do you consider it too late after lumpectomy to offer adjuvant whole breast radiotherapy?
I don't know if there are studies which have looked at this - to say there is no benefit at a certain time frame. Retrospective studies have shown higher local recurrence with delay of RT with variable time period in those studies (8 weeks to 20 weeks) . The most recent one from British Columbia loo...
What is your advice to patients who ask if dental X-rays correlate with oral/oropharyngeal cancer?
No good data to support positive correlation between dental X-ray and oral/oropharyngeal cancer Bharat
Do you use breath hold techniques to minimize heart dose in whole breast radiation?
We do 2 CT scans (free breathing and deep breath hold) for every patient with left sided breast cancer treated in the supine position. We then create volumes and blocks for both scans and select the DIBH plan if it offers a clear advantage. Our approach is to attempt to keep mean heart dose under 1 ...
Is it acceptable to use SBRT for prostate bed RT?
In my opinion, this should not be done outside of an IRB-approved research study. We are beginning to see some published experience with moderate hypofractionation in post-prostatectomy patients, which would indicate, at least preliminarily, that this approach may be safe, although the optimal dose ...
Would you hypofractionate breast cancer patients with >25 cm separation?
According to the most recent ASTRO whole breast fractionation guideline, the decision to offer HF-WBI should be independent of breast size (including central axis separation) provided that dose-homogeneity goals can be achieved. The guidelines recommend that the volume of breast tissue receiving gre...