Radiation Oncology
Expert insights on radiation treatment planning, techniques, toxicity management, and multimodal cancer care.
Recent Discussions
How would you treat a metastatic small cell carcinoma of the larynx that is locally progressing on cisplatin/etoposide?
I assume metastatic means distantly metastatic. 30 Gy/10 fx or 20 Gy/5 fx local regional RT if progressing on chemo.
How would you approach an early stage node negative breast cancer s/p BCS with a history of severe chest wall burns?
I would favor APBI to minimize volume treated.
How do you account for previous dose from I-131 when delivering external beam radiation therapy near the thyroid bed?
Since I-131 is selectively taken up by thyroid cancer cells and the range of beta particles emitted is 1-2 mm, there should not be any big concerns of overdosing OARs. https://ehs.stanford.edu/reference/i-131-radionuclide-fact-sheet http://www.docs.csg.ed.ac.uk/Safety/rpu/gn/GN009.pdf.
What plan parameters do you prioritize in 3D conformal breast treatment planning?
For whole breast 3D conformal RT, we contour surgical bed with 1 cm expansion for CTV and 3-5 mm for PTV.Coverage whole breast 95% of volume to 95% of dose we aim for but we accept 90 to 95.PTV (surgical bed) as above, 95% of volume to 100% of dose but accept 95 to 95 also.Volume of breast getting 1...
How would you treat a bone oligometastasis that required surgical fixation for pathologic fracture?
It really boils down to the clinical scenario and the approach of the operation. Any time there is a possibility that the surgical procedure may shove the tumor/ tumor cells into the medullary cavity, one will need to include the whole surgical hardware in the RT field. A cone-down or simultaneous b...
Would you consider SBRT for an intraocular/choroidal metastasis?
For solitary choroidal metastasis, I would recommend eye plaque brachytherapy using I-125 seeds with a dose of 4000 cGy at the apex in about 90 +/- hours. If the tumor is abutting or close to the optic disc, use a notched plaque instead.
How would you approach a small, node-negative (cT1-2N0) nasopharyngeal cancer in a patient with prior H&N cancer treated with surgery and radiation?
RT to primary and RP nodes. Positive nodes in previously irradiated neck likely 10% or less, so I’d observe neck.
How do you approach treatment of an unresectable sacral chordoma?
Definitive RT, preferably with protons.
What GTV to CTV expansion do you use for limited stage small cell lung cancer with IMRT?
It seems to me that in stage III NSCLC cases, the CTV of the primary tumor in the lung and the CTV of the nodal volumes would be drawn differently for maximum efficiency: Primary: GTVp --> iGTVp --> + 5-7 mm = CTVp --> + 5 mm = PTVp Nodal: GTVn --> + 5-7 mm + entire nodal station (if desired) + el...
How you approach treatment of a glioblastoma in the setting of prior WBRT for a metastatic non-CNS malignancy?
I think treatment to 25 Gy in 5 fractions or 40 Gy in 15 fractions to areas of enhancement and/or post-op bed can be safely delivered after whole brain (assuming the patient was treated to 30 Gy in 10 fractions). We commonly treat with SRS after whole brain RT. Just be cognizant of cumulative dose t...