Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
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: ...
What are indications for RT coverage of pleural cavity for margin positive resected Askin tumor after neoadjuvant chemotherapy?
Patients with malignant pleural effusion, pleural violation (2/2 chest tube placement through tumor) or pleural nodules at diagnosis should be considered for whole-pleural surface RT at the time of local RT to the chest wall. Of note, patients w/out + margins would also be considered for whole pleu...
Given in RTOG 9601 that patients who had a pre-RT PSA <0.7 did not derive a survival benefit with ADT, why was other cause mortality evaluated in patients with PSA <0.6 as noted in this year's plenary?
I am not sure the exact question as it could be interpreted as 1 of 2 things. 1. Was a different cutpoint used in the NEJM paper and in the ASTRO plenary? -No. The median PSA of the trial was 0.6 ng/mL. The NEJM used <0.7 (0.2-0.6) and the ASTRO plenary simply used < or = 0.6 (0.2-0.6). Just a diffe...