Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
What is the best fractionation for head and neck patients who cannot receive systemic therapy due to KPS or medical comorbidities?
In my experience, using the DAHANCA regimen (once daily 4 days a week, twice daily once a week), but treating only PTV1 in the second daily fraction, is quite well tolerated. The original DAHANCA treated all targets twice daily. However, using IMRT it is possible to avoid prophylactically irradiated...
When would you use PSMA PET over conventional imaging for prostate cancer?
So far, most (but not all) prospective data for molecular imaging has been obtained in the setting of biochemical recurrence and that is where I have used it most outside of trials.In the primary disease setting, some trials examined the utility to detect nodal and distant disease (like OSPREY publi...
How would you manage a patient with a subcentimeter stage I vaginal squamous cell carcinoma after a positive deep margin post local excision?
I would get MRI with vaginal gel done along with PET/CT (assuming negative) If there is no LVSI on pathology, disease is not high grade and based on MRI, I would cover vaginal wall apical residual thickness with intracavitary brachytherapy then I would treat with 7Gy x5 prescribed to volume and lim...
Can pre-op chemoRT be used to potentially downstage an early stage rectal cancer (i.e. T2 N0) for a sphincter sparing operation?
It is certainly appropriate to consider pre-operative chemoRT in an early stage rectal cancer that would not otherwise require neoadjuvant chemoradiation.The goal here would be to convert the operation from one resulting in a permanent ostomy (APR) to one allowing sphincter sparing (LAR). Good data ...
What is your typical target/field when treating a patient with 5 Gy x 5 fractions pre-operatively for rectal cancer?
The European experience with short course preoperative radiotherapy uses treatment portals that are somewhat smaller than what many of us utilize in the US. At Washington University we have a long experience (that pre-dates the Swedish trials) with 4Gy X 5fx for readily resectable tumors. The cases ...
Would you offer additional radiation therapy in a medically inoperable patient with rectal adenocarcinoma who has a persistently palpable tumor after definitive chemoradiation therapy?
I recently was writing up some data about pCR after SBRT for lung and it still seems a bit of a surprise to folks that pCR rates increase over time after XRT. The velocity of this change over time is almost certainly related to histology and other factors like tumor doubling time. It's all about the...
Is there a role for unilateral hippocampal sparing?
There is some lateralization of hippocampus function which may impact decision making.The left hippocampus seems to play more of a role in episodic verbal memory, while the right plays more of a role in spatial processing. Our neurosurgeon has told me before that a left hippocampectomy is much worse...
Do you give post-operative radiation to Ewing sarcoma if there is poor histologic response to neoadjuvant therapy in a completely resected tumor?
US Ewing studies conducted through COG have used histologic response in more recent protocols to play a key role in how margins are assessed, such that patients with >90% necrosis and inflammatory or coagulative necrosis at the margin require RT, while those with bland scar or fibrous tissue do not....
What is your follow up schedule after completion of RT for pediatric rhabdomyosarcoma?
Imaging surveillance is an interesting and yet complicated issue. If a child is enrolled upon a prospective randomized trial for which informed consent has been given, then every effort should be made to follow the protocol guidelines, which are designed to answer a protocol question. However, patie...
What is your approach to treat metastatic poorly differentiated thyroid cancer with papillary features?
The easy answer is that there is a role for I-131 if the remnant disease (tumor bed or mets) is iodine avid. Harder and perhaps more realistic is that the test dose of 2-3 mCi is too low and you have to overwhelm the iodine receptor with at least 30 mCi to activate a radiologic response. If you are ...