Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
Would you consider omission of radiotherapy in patients 70 years and older with invasive ductal carcinoma who had initially positive lumpectomy margins, but had no residual disease upon re-excision?
The only data I know of on this specific subject comes from the subgroup analysis of the PRIME II trial, which randomly assigned patients to endocrine therapy alone or with radiation therapy. Its eligibility criteria included age 65 or older, tumor size 3 cm or smaller, grade 1 or 2, either grade 3 ...
When giving total neoadjuvant therapy for rectal cancer, do you sequence radiation and chemotherapy differently depending on the tumor distance from the anal verge?
With all of the emerging data in rectal cancer and, particularly, if considering non-operative management, I think it is crucial to discuss these patients as part of a multidisciplinary team now more than ever. Prior to starting any therapy, we try to ensure that all of our newly diagnosed rectal ca...
For a glioblastoma patient who had an MRI immediately postoperatively and you are able to repeat one closer to the time of CT simulation, do you use the more recent scan or the immediate postoperative scan for contouring (T2/FLAIR and T1 post)?
We usually obtain a repeat MRI closer to the time of CT sim, ideally on the day of sim, for several reasons. First, surgical cavities have a tendency to collapse which may impact target volume delineation. Secondly, peritumoral edema T2FLAIR signal infrequently subsides, which may also affect target...
In what situations would immunotherapy alone be appropriate for non-metastatic NSCLC?
Based on our current SOC treatment paradigms for patients who don't have contraindications to definitive treatment options, my short answer would be no. However, few caveats to that no as always. Few examples where I think this would be an appropriate approach based on currently available data. Poor...
Would you recommend XRT treatment fields of a locally recurrent prostate cancer s/p RP similar to salvage vs intact prostate treatment?
I will generally approach the treatment fields similarly to any other post-prostatectomy recurrence. Unless the anatomy is unfavorable, I will try to treat the full CTV per guidelines (the Francophone guidelines were published in 2021 and provide updated guidance). The toxicity rates to treating the...
Is there a volume or size criteria where you feel that standard doses for palliative radiation (8Gy/1fx-30Gy/10fx) are not effective?
At the risk of running off the mathematical rails, I thought about this question from a completely non-clinical viewpoint (from a clinical viewpoint, yes, I would probably use a bit more than 30/10 for a big 10 cm mass). Here are a few assumptions. First, the D-sub-zero (D0) for many tumor systems h...
What maximum volume (in cc's) of small bowel would you allow to receive 45 Gy in a patient with node positive squamous cell carcinoma of the anal canal receiving concurrent chemoradiation with 5-FU/MMC being treated with IMRT?
This is a very good question because this comes up very commonly in female patients. The first thing to recognize is that the 45Gy microscopic dose is overtreatment for anal cancer. Your V35 is probably an effective microscopic dose. From the to 2D and 3D Era, 30.6 Gy in 17 fractions is an effective...
What are your top takeaways in Breast Cancer from ASCO 2023?
SONIA: A notable trial comparing CDK4/6 inhibitors as 1st line vs. 2nd line treatment. AI+CDKi combination therapy as 1st line does not improve OS, 2nd PFS, or QOL compared to combination therapy as 2nd line. Factors such as the site of metastasis, tumor burden, symptoms, cost, and side effects sho...
What is the role of a simultaneous integrated boost in vulvar cancer to the primary and nodes?
We typically do a SIB at 2 Gy per fraction to the vulvar GTV and nodes and then do a sequential boost to follow (CTV is treated at 1.8 to CTV in 25 fractions). Presumably, the nodes could be safely treated at a higher dose per fraction since there is typically not a critical structure in close proxi...
In a patient diagnosed with prostate cancer based on a biopsy many years ago placed on surveillance now with rising PSA, do you require repeat biopsy prior to definitive radiation treatment?
This question raises multiple important points that I will discuss, but given that the question doesnt have patient age or numerous other important factors I will speak generally with multiple assumptions being made that he is ~65yo with >10 years life expectancy, etc:1. The question is in fact wron...