Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
Is there a way to predict clinically or from CT which patients with left sided breast tumors would benefit more from the prone v. supine position?
We only set up patients in the prone position that do not require nodal radiation. I find that large breasted patients are most likely to benefit from a prone position.
When giving a breast boost, what are indications for a photon breast boost?
In general, once the surgical cavity depth approaches 5 cm then it is harder to cover with electrons. That being said, for these patients with disease in the outer quadrant, the lateral decubitus position helps significantly to bring the cavity close to the surface. We published this data: http://ww...
In laryngeal cancer (assuming no pharyngeal extension) with level II/III involvement, should RPs and level IB on the involved side be covered?
I do not cover RP, level Ib, or level V electively in the scenario you describe. I will cover level VI if the disease has broken through thyroid cartilage into soft tissues anteriorly (usually these patients go for total laryngectomy) or if there's subglottic extension.
Should patients with anal canal SCC undergo an FNA biopsy of any palpable inguinal LN that is also FDG avid on PET/CT or should these nodes be assumed to be positive and treated to a higher dose?
Even though PET/CT can be falsely positive in the inguinal region, in the era of IMRT we treat all metabolically positive node with the presumption that it is disease. Would not necessarily rely on FNA as this could be a sampling error. Since therapeutic dose can be delivered safely, I would err on ...
What do you consider negative or close margins for tonsillar cancers?
To answer your first question about margin for HPV+ (I assume) tonsillar cancers, one would have to go with the definition on clinical trial. Currently the WashU trial as well as RTOG 1221/ECOG 3311 and the ADEPT trial uses the 3mm cutoff. So a free margin is defined as something>/=3mm. Anything <3m...
When treating a patient with a high grade sarcoma in the post op setting, do I need to get full dose to the incision and drain site (assuming all margins negative)?
No, I would treat the incision and drain site with 45 Gy in 25 fractions using bolus only.
Does the dose rate of an external beam linear accelerator matter in terms of radiobiology?
Per Hall, "The dose-rate effect caused by repair of sublethal damage is most dramatic between 0.01 and 1 Gy/min; [a]bove and below this dose-rate range, the [cell] survival curve changes little, if at all, with dose rate." "Old" linacs could pump out about 6 Gy/min; new ones, up to 24 Gy/min. Sublet...
How do you boost patients with squamous cell carcinoma of the cervix or upper vagina with invasion of the posterior bladder?
It depends on the distribution of diease and whether there is a fistula or not. If there is relatively small bladder invasion, intracavitary may provide adequate coverage; MRI-based planning is recommended. If it is a large tumor with very extensive bladder inolvement (which usually is associated wi...
Per 2016 NCCN guidelines, is the addition of 6 cycles docetaxel now the standard of care for all (NCCN) high and very-high risk prostate cancer patients receiving definitive XRT/ADT?
Last year, the results of RTOG 0521 were presented at ASCO and showed that adjuvant docetaxel led to a small improvement in overall survival for men with high risk prostate cancer. To briefly recap, 563 eligible subjects were randomized to standard-of-care external beam RT (72-75.6Gy, with 46.8 to r...
Is there any data on an effective RT regimen (dose/fractionation) for inducing an abscopal effect using a PD-1 inhibitor in refractory Hodgkin's lymphoma?
I'm not aware of any published data for HL. There is a phase I-II study on low-grade B-cell lymphoma: "In situ vaccination with a TLR9 agonist induces systemic lymphoma regression: a phase I/II study" by Brody et al (J Clin Oncol. 2010 Oct 1;28(28):4324-32) that used a dose of 2 Gy x 2. There is an ...