How do you contour a resected brain metastases for fractionated partial brain radiation?
What is your GTV, CTV and PTV? If giving 30 Gy in 10 fx, does the contour need to extend all the way to the cut in the skull on both sides (is there a risk of failure at the bone resection site)? Is it safer/preferable to use 3D rather than IMRT/VMAT if the site is not near a critical structure?
Answer from: Radiation Oncologist at Academic Institution
When treating a resection cavity in the brain after surgical excision of the tumor, I contour the resection cavity on a Gd-contrast enhanced volumetric MRI. For most large metastases, an average cavity volume reduction of 15% to 43% has been reported in several published studies within 3-4 weeks aft...
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Answer from: Radiation Oncologist at Community Practice
If you're just giving 30 in 10, I don't think you have to sweat the details much, after all, you could give the whole brain 30 in 10. If your equipment is limited, you could try a wedged pair or 3 field plan to spare structures like the lens, salivary glands, and hippocampus, if possible. Using 2d o...
Answer from: Radiation Oncologist at Community Practice
I agree with @Baldassarre Stea's excellent summary.
And @James R. Baer brings a good point - no need to worry about margins as much or OAR for 30 in 10.
If this was a resected brain metastasis, either offer HA-WBRT (using whole brain as per the initial Patchell study) or use post-ope...