Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
In a patient with pancreatic cancer who is heterozygous for the ATM c.875C>T (Pro292Leu) mutation with functional impairment in the gene product, is there any data or recommendation to support using SBRT vs. chemo-RT?
Ablative-dose radiation (100 Gy BED) is a curative option, with LC and OS similar to surgery. Everything else is palliative. 50 Gy in 5 fx with MRgRT is an evolving standard. The patient should be informed that this option is available at many centers. Otherwise, any palliative dose is fine. With th...
Would you consider RNI in a patient with axillary recurrence after lumpectomy, whole breast RT and cavity boost 10 years ago?
This patient has residual nodal disease after neoadjuvant chemotherapy and has a high risk of recurrence. I have typically treated the supraclavicular fossa and at risk axilla using a VMAT technique to limit skin dose in the area of overlap. You have 10 years of repair and the patient should tolerat...
When should surgical tumor resection be considered in patients with a low-grade glioma?
In adults with low-grade gliomas, there is substantial evidence suggesting that aggressive, early surgical resection improves outcomes and survival (Jakola et al., PMID 23099483). Historically, this has been particularly true for tumors that carry an IDH mutation or 1p/19q codeletion. This survival ...
Do you obtain MRI for cutaneous SCC with microscopic PNI to assess for gross perineural tumor spread?
I would recommend both an MRI as well as consulting the pathologist regarding the exact nature of the PNI. We had an experience with more than 100 patients (Sapir et al., PMID 27475277). Those with gross PNI (evidenced by MRI, with or without cranial nerve deficit) and microscopic extensive PNI (>2 ...
What do you use for IGRT for definitive H&N IMRT treatments?
"IGRT" for head and neck can encompass a lot of concepts, so matching the application to the technology is useful. Briefly, for head and neck, IMHO:A) Non-adaptive bony isocentric alignment with stable anatomy (e.g. most-post-op) - KVX>= CBCTB) Patients with multiple CTVs/OARs who are at risk for we...
How would you approach an isolated prostate recurrence of high-risk prostate cancer following definitive EBRT?
It is important to know: 1) time from cessation of hormones and time to recurrence. Better to also have T levels. 2) velocity of PSA rise. 3) absolute PSA value Longer disease free interval, slow PSA kinetics and low PSA suggests prostate only recurrences. I have also begun to incorporate Aximun s...
When treating adenocarinoma of the pancreas to 75 Gy in 25 fractions, what dose constraints do you use for small bowel, large bowel, and stomach?
Planning Volumes Definition Doses by Fractionation Scheme 15-Fraction 25-Fraction Microscopic Extension PTV CTV + 5mm (CTV = GTV + 1cm + CA, SMA, +/- porta hepatis, +/- splenic hilum basins) 37.5Gy/15 45Gy/25 High Dose PTV GTV + 5mm margin excluding GI PRV expan...
Would you recommend completing prostate SBRT without fiducials?
In the era of 3D imaging with CBCT, I don’t see we need fiducial marker routinely.
How do you approach re-treatment if a patient still has pain from spine metastasis after 30 Gy in 10 fractions?
There is a myth in radiation oncology that 30 Gy in 10 fractions (MF) is more durable than single fraction (SF) regimens. On average, patients treated with SF or MF regimens have pain relief that lasts about 4 months. On average, 50% of patients experience recurrence of pain, regardless of the initi...
How do you manage significant gas in patients undergoing pelvic radiotherapy?
This is tough, especially once the simulation is completed, the patient comes in for treatments and now you see very different anatomy. The one thing that I have changed in practice - and I'm aware this is not always possible at higher volume centers - is to have the simulation at about the same tim...