Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
In what circumstances would you offer adjuvant radiation after resection of vulvar mucosal melanoma?
If immunotherapy is indicated, I would start that right away. I would treat for positive margins or melanoma in situ at the margins using 30/5-6 fx twice a week. Would treat the tumor bed with a 10-15mm margin. I wouldn't treat the groins. Would also recommend a thorough GYN exam in the OR if not d...
Is it appropriate to use photon energies above 15 MV for prostate SBRT?
We have abandoned energies of 15MV or greater in our entire clinical enterprise. We do so much IMRT that the risk of neutron production with higher energies is not worth it. Furthermore, multi field IMRT or SBRT eliminate the need for the high energies. Our standard machine configuration is 6MV & 10...
How would you treat a patient who has an inguinal p16+ SCC lymph node of unknown origin?
We have published a 60% 5yr OS for SCCa of unknown primary. The two most likely primary sites are anal cancer and vulvar cancer. Please see my previous posts for anal cancer doses. I would treat this patient to the ipislateral inguinal external and common iliac nodes. Once could consider treatment o...
Given results of SAKK 09/10 in which dose escalation for salvage prostate radiotherapy to 70 Gy was not superior to 64 Gy, would you ever consider a higher dose?
For years, the dogma was that you needed at least 66 Gy to control disease in the prostate bed in patients with a biochemical failure. The SAKK 09/10 trial seemed to challenge that notion. Even in this population of patients who were relatively favorable in the sense that they were node negative, an...
Is there a risk of increased skin toxicity with combined radiation and doxycycline?
No reports that I am aware of. Tetracyclines have an absorption wavelength of ~300-350 nm and can be pushed into an excited energy state by primarily UVA (320-400 nm) waves. Relaxation back to base state leads to chemical reactions that generate photoproducts that serve as antigens in a cutaneous al...
Do you take any special precautions when treating cervical spine metastases?
For each spine met case, it's important to determine whether it's a surgical or radiotherapy case. Spinal instability neoplastic score (SINS) and Bilsky grade (epidural cord compression) are two important parameters to consider. If SINS is 6 or below and if Bilsky grade is 1c or below, surgical inte...
Do you refer all patients with new findings of CNS or epidural mets/tumor to ED for evaluation or are there some that can be managed completely outpatient?
Interesting question: Sending patients to the ED for non-emergent conditions is not advised. Our EDs around the country are struggling for a variety of reasons (e.g., they are often holding patients awaiting placement or admission), thus our society will benefit by us avoiding sending patients to t...
How would you manage asymptomatic radiation necrosis seen on MRI after SRS of a benign tumor?
About half the time, the MRI findings resolve or stabalize over time. We repeat the MRI every 6-12 weeks depending on how concerning the MRI findings are, stability, degree of edema, location of radionecrosis, etc.. If the patient becomes symptomatic, we start steroids and refer to a neurosurgeon ex...
How would you manage the contralateral neck and adjacent structures for a glossotonsillar or glossopharyngeal sulcus primary cancer if well lateralized?
The glossopharyngeal and glossotonsilar sulci are the grooves between the lateral oropharyngeal wall or the tonsil and the base of the tongue, representing a very lateral OPC location that does not require contralateral neck RT. The main neck nodes at risk are II and III. In the absence of significa...
How long should patients wait before undergoing reconstruction following PMRT?
Our approach is to wait for 6 months, which is based on the preference of plastic surgeons. There is published data showing a higher risk of complications if done sooner than 6 months and this forms the rationale for that wait.