For gyn cancers receiving chemoradiation, how high can you boost grossly positive nodes with SIB if not near bowel?
SIBs of 55-57.5 Gy in 25 fractions are frequently mentioned with bowel volume constraints at this dose, but assuming there is no bowel nearby (e.g., boosting an external iliac node), should you push this higher? For instance, 65 Gy in 25 fractions would have an EQD2 near 70 at an alpha/beta of 10 compared to 56 Gy2 for 55/25.
Answer from: Radiation Oncologist at Academic Institution
I have not attempted to push the dose further than it is written in EMBRACE II. Keep in mind that this is at a higher dose per fractionation (as high as 2.3Gy per fraction) than we typically use. Assuming an alpha/beta of 10 for SCC this calculates to a BED ~ 58Gy for the diseased node, but a higher...
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Answer from: Radiation Oncologist at Community Practice
I typically will give a simultaneous integrated boost (SIB) of 60 Gy in 30 fractions to the pelvic and para-aortic nodal CTV, which is the PET positive GTV plus a 3 mm margin. If possible I will boost the GTV of larger gross nodes (>1 cm) to 66 Gy (2.2 Gy/fx) with no margin, if constraints can be...
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Radiation Oncologist at Mon Health
I have found that paraaortic radiation is very tol...
I have found that paraaortic radiation is very tol...
Answer from: Radiation Oncologist at Community Practice
EQ2 calculation doesn’t take time factor into account and also contributions from brachytherapy for pelvic nodes.
Answer from: Radiation Oncologist at Academic Institution
I will usually go for 55-60 Gy in 25 fractions based on location with 45 in 25 to the remainder of elective nodal regions. GTV + 5mm to PTV. Goal is to keep the treatment isotoxic, however, so will turn down the dose at interface of bowel, always, and bladder/rectum as necessary.
While Dr. @Howell&...