Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
How do you respond to a patient who asks "Why do I still need breast radiation after chemotherapy if chemotherapy treats the whole body?"
Perhaps one of the best arguments supporting RT in breast cancer is the not-that-often cited Scottish Trial that randomized women to postoperative RT or chemotherapy following breast conservation; the breast failure rate following adjuvant chemotherapy alone approximated 30% with short follow-up. Ob...
What adjuvant treatment would you offer a patient who underwent cystoprostatectomy for a muscle invasive bladder cancer and discovered to also have prostate cancer?
Complex case. If they have an indication for prostate RT (major: positive LN, persistent PSA, +SVI, minor: + margins, +ECE), I would consider treating the prostate fossa +/- LNs. As far as the bladder, we don't have the answer yet, but high-risk patients are being studied on the BART study from Tata...
What methods do you use to prophylactically reduce radiation dermatitis for head and neck irradiation?
My approach has been: Start Remedy (less greasy but less effective) and/or Aquaphor (more greasy but more effective) 3-4x daily at beginning of RT. Try to use Aquaphor at least at night when the greasiness is less bothersome. If patients have some other alcohol-free/non-anti-oxidant product they re...
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...