Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
Would you offer local radiotherapy to prostate in a patient with small cell neuroendocrine carcinoma who had a complete response to chemotherapy?
Thank you for this great question. Yes, I would strongly consider radiation therapy to the prostate and pelvic LNs for small cell carcinoma of the prostate. Small cell carcinomas of the prostate are rare and comprise <1% of all prostate cancers and are known to be more aggressive. They are often unr...
When treating bladder cancer with 55 Gy in 20 fractions, what small bowel dose constraints do people use?
Yes, it is hard to tell what happened on that trial because we don't know how often small bowel might have been excluded from the PTV. It would be nice to hear from others, like @Dr. First Last. And maybe theMednet can get Dr. James to join? For what it is worth, when this is an issue, I treat with...
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...