Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
For treatment with EBRT for H&N cancers, what is the consensus for CT simulation?
I agree with Dr. @James Caudell regarding the impact of CT contrast on IMRT/VMAT-based planning. Although I do not routinely perform a contrast and a non-contrast scan on H&N patients. The impact of IV contrast on IMRT dose distribution has been extensively studied, and the impact on the H&N region ...
Would you ever consider stopping immunotherapy in a patient with metastatic melanoma after achieving a good response?
Yes, I would consider stopping immunotherapy in a patient with metastatic melanoma after achieving a good response.Data of 655 melanoma patients treated in pembrolizumab phase 1 KEYNOTE-001 study has shown 95 patients (14.5%) achieved CR after a median follow-up of 32 months. Treatment was discontin...
How do you approach treatment of a glioblastoma in pregnancy?
Glioblastoma during pregnancy could be treated safely (to mother and fetus) with certain precautions and modifications. Collaboration and consultation with the patient’s obstetrician are essential. External shielding over the patient’s abdomen during treatment will decrease the external scatter radi...
Are there any scenarios in which you would offer SBRT as your preferred treatment approach for appropriate candidates with intermediate risk prostate cancer?
Based upon the PACE-B trial, 40 Gray to the prostate, 36.25 to the PTV, which was compared to standard or moderately hypofractionated radiation, and documented non-inferiority. It is reasonable to consider stereotactic radiation therapy as a standard of care for intermediate-risk prostate cancer. If...
Would you offer hippocampal sparing whole brain radiation for patients with brain metastases due to ES-SCLC?
Until we have built-in auto-segmentation, I find the RTOG contouring atlas very helpful for manual contouring of the hippocampus. I tend to use the lateral ventricle as my main landmark, and look for the circle of gray matter located medial to it. Once I've drawn a hippocampus, I'll look at it in th...
Can we use a linear accelerator to sterilize PPE?
Per FAQ's posted by ASTRO: "At this time, ASTRO does not recommend the use of clinical linear accelerators to sterilize PPE. While ionizing radiation is used for sterilization of blood and food products, this is achieved using industrial irradiators that use gamma irradiation at doses rates far grea...
Are there any volumetric constraints associated with toxicity in the dose range that is moderately above prescription (i.e. 30-35 Gy range), when planning hippocampal-sparing whole brain radiation?
This is an important question worth some discussion. As the question mentions, clinical trials of HA-WBRT have permitted a hot spot of 133% of the prescription dose of 30 Gy (or 40 Gy) to D2% of the whole-brain parenchyma as an acceptable protocol variation. Importantly, none of these trials have de...
Is a stereotactic/ thin-slice MRI of the brain absolutely necessary to determine eligibility for hippocampal sparing whole brain radiation therapy?
The small size of the hippocampal dentate gyrus (3-4cc) can render it difficult to delineate and conformally avoid if both the brain MRI and the treatment-planning CT simulation are not obtained with thin-slice axial images (not exceeding 1.5mm on the MRI, not exceeding 2.5mm on the treatment-planni...
Would you ever consider treating a patient with locally advanced NSCLC with SBRT to the primary tumor plus conventional mediastinal chemoradiation?
I would await the results of LU008 before doing this off-trial. The Phase 2 results from Heinzerling et al., PMID 39615497, that supported the development of LU008 statistically failed to meet its primary endpoint of >60% 1 year PFS (although it was likely just underpowered at 61 patients), but more...
How are you using predictive tests such as DCISionRT (PreludeDx) or OncotypeDX DCIS in the management of DCIS?
Advantages: It's a relatively cheap, simple assay to better individualize risk of DCIS. Not only prognostic like Oncotype DCIS but also predictive of the absolute benefit of radiation. Supposed to be a better risk assessment tool than traditional clinical pathologic factors. Can identify those who ...