Is it necessary to use double contrast MRI for treatment planning of brain SRS?

"Necessary" is perhaps too restrictive a term, but speaking anecdotally, at Barrow Neurological Institute (BNI) we, for essentially the past 20 years, routinely obtain thin cut (1mm) SPGR double-dose gadolinium MRI to plan radiosurgery for patients with brain metastasis. In support of this, a recent retrospective report by Garcia and colleagues at UCSF (J Neurosurg 126:1756–63, 2017) evaluated high-resolution double-dose gadolinium GammaKnife planning MRIs in 326 patients, at a median 22 (rang...

The simple answer is no. The Garcia publication discussed above is a very good example of a high quality retrospective review. A caveats of that is that UCSF is well oiled machine when it comes to GK SRS. The patients are reviewed at SRS chart rounds so even if new lesions show up they are triaged accordingly. Routine FU with MRI Q3mo with quality imaging may be well more important that the add'l gadolinium. And most importantly, this wasn't a study of if treating those small lesions mattered si...