Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
In patients with low metastatic burden receiving prostate directed therapy with MRI confirmed invasion of the seminal vesicles, would you include the SV in your field?
Yes, as one of principals of local treatment helping with survival in stage IV disease is eliminating it's source of future metastatic clones not sensitive to ongoing treatment. Thus, makes sense to treat all visible local disease with RT.
How would you manage a patient with T3N0 rectal cancer status post transanal excision, who is not a surgical candidate, and who received pelvic radiation for prostate cancer 20 years ago?
Abdominal or abdominoperineal resection. T3 tumors have a 20+% risk of recurrence despite radiation and local excision. If truly T3N0, the risk may be the same with surgery. And reirradiation is fraught with risk.
What ITV to PTV expansions do you use for free-breathing NSCLC SBRT using CT sim with 4DCT?
5mm concentric PTV margins. Even with daily IGRT and fluoro, I find 3mm to be very tight and adding a little more margin does not change the OAR doses much unless PTV is touching. If 4DCT not available in sim, I do 7mm sup/inf and 5mm in other directions. I do not specifically add a CTV margin, but ...
What is the optimal management of patients with stage II lung cancer without nodal metastasis, but unresectable due to poor pulmonary reserve?
This population of stage II patients without nodal involvement would include T2bN0 (stage IIA) or T3N0 (stage IIB) disease. NCCN 2020 lists either CRT or hypofractionated RT/SBRT as acceptable options. In my experience, if these patients are nonsurgical, then they typically also have multiple co-mor...
What ITV to PTV expansions do you use for free-breathing definitive IMRT for locally advanced NSCLC using CT sim with 4DCT?
This seems like a simple question, but it is not! It is missing something...the concept of the CTV (clinical target volume) is missing within the question. The idea of the CTV is to include microscopic disease within the region receiving full dose. In the case of locally-advanced lung cancer, CTV is...
How do you approach a SCC of unknown primary that is metastatic to a submental (level IA) lymph node?
I would approach both p16 positive and negative cancers the same way for a level IA lymph node. After complete workup including PET/ CT and directed biopsies, if the patient is truly diagnosed as a unknown primary squamous cell ca, I would recommend a neck dissection. If the patient has had a good n...
How do you manage Paget's disease of the nipple?
I think of Paget's as a special form of DCIS +/- invasive cancer. We do not routinely perform breast MRI here for this diagnosis (but I can see the utility of this if there is any uncertainty about the extent of the lesion). We consider the local therapy principles to be similar to other early-stage...
What is the optimal duration of ADT for cN1 disease with EBRT?
Unfortunately there are no prospective data to guide management for cN1 prostate cancer treated with EBRT. The NCCN guidelines do not comment on the optimal duration of ADT in this setting. While 18 months may be considered for some patients with high risk cN0 prostate cancer as per the PCS IV trial...
How would you manage a resected meningioma found to harbor a small focus of metastatic disease from a non-CNS primary malignancy?
Mets to a tumor (Collision) are seen, though rare. Simple answer: 1. Meningioma resection (Grade 1) or for that matter up to Grade II, irrelevant since the time to progression in a less than a Simpson Grade I resection would far outrun the metastatic cancer. 2. Treat the resection cavity like a met ...
How would you approach local recurrence of scalp angiosarcoma during the course of adjuvant radiotherapy after a widely R0 resection?
I've had similar. I had to cover the entire scalp using tomotherapy as tumor progressed when I wasn't looking. We treated with concurrent taxanes as there was a suggestion in the literature to do this and had a reasonable response. Suggest you resimulate and patch treatment fields.Try this article: ...