[Ga]-DOTATATE PET/MRI as an adjunct imaging modality for radiation treatment planning of meningiomas.

Title[Ga]-DOTATATE PET/MRI as an adjunct imaging modality for radiation treatment planning of meningiomas.
Publication TypeJournal Article
Year of Publication2021
AuthorsMahase SS, O'Brien DARoth, No D, Roytman M, Skafida ME, Lin E, Karakatsanis NA, Osborne JR, Brandmaier A, Pannullo SC, Ramakrishna R, Stieg PE, Knisely JPS, Ivanidze J
JournalNeurooncol Adv
Date Published2021 Jan-Dec

Background: Meningiomas express high levels of somatostatin receptor 2 (SSTR2). SSTR2-targeted PET imaging with [Ga]-DOTATATE can aid with distinguishing residual meningioma from reactive changes in the postoperative setting. We present initial dosimetric analyses, acute events, and local control data utilizing [Ga]-DOTATATE PET/MRI-assisted target delineation for prospectively-treated intermediate-risk meningiomas.

Methods: Twenty-nine patients underwent DOTATATE PET/MRI meningioma evaluation in 2019. Eight patients with 9 postoperative meningiomas met RTOG 0539 intermediate-risk criteria (recurrent WHO grade I, 1/9; WHO grade II, 8/9). Target volumes were created using DOTATATE PET/MRI to determine residual disease and received a nominal dose of 35.0 Gy over 5 fractions. For comparison, cases were recontoured and planned with MRI alone per RTOG 0539 guidelines. Mean and maximum equivalent 2 Gy doses were generated for target volumes and organs at risk (OAR) within 1 cm of the PTV and compared using Wilcoxon matched pairs signed rank test.

Results: DOTATATE PET/MRI-guided planning significantly reduced mean PTV (11.12 cm compared to 71.39 cm based on MRI alone, < .05) and mean and max dose to the whole brain, optic nerves, and scalp. PET/MRI plans resulted in at least 50% reduction of mean and max doses to the lens, eyes, chiasm, cochlea, brainstem, and hippocampi. One patient experienced focal alopecia. There were no local recurrences at 6 months.

Conclusion: Incorporating DOTATATE-PET/MRI for postoperative target delineation in patients with intermediate-risk intracranial meningiomas results in PTV reduction and decreased OAR dose. Our findings warrant larger studies evaluating DOTATATE-PET/MRI in the radiotherapeutic planning of postoperative meningiomas.

Alternate JournalNeurooncol Adv
PubMed ID33738446
PubMed Central IDPMC7954102