Somatostatin Receptor Targeted PET-Imaging for Diagnosis, Radiotherapy Planning and Theranostics of Meningiomas: A Systematic Review of the Literature

Abstract

The aims of the present systematic review are to: (1) assess the diagnostic performance of somatostatin receptor (SSR)targeted positron emission tomography (PET) with different tracers and devices in patients affected by meningiomas; and (2) to evaluate the theranostic applications of peptide receptor radionuclide therapy (PRRT) in meningiomas. A systematic literature search according to PRISMA criteria was made by using two main databases. Only studies published from 2011 up to March 2022 in the English language with ≥10 enrolled patients were selected. Following our research strategy, 17 studies were included for the assessment. Fourteen studies encompassed 534 patients, harboring 733 meningiomas, submitted to SSR-targeted PET/CT (n = 10) or PET/MRI (n = 4) for de novo diagnosis, recurrence detection, or radiation therapy (RT) planning (endpoint 1), while 3 studies included 69 patients with therapy-refractory meningiomas submitted to PRRT (endpoint 2). A relevant variation in methodology was registered among diagnostic studies, since only a minority of them reported histopathology as a reference standard. PET, especially when performed through PET/MRI, resulted particularly useful for the detection of meningiomas located in the skull base (SB) or next to the falx cerebri, significantly influencing RT planning. As far as it concerns PRRT studies, stable disease was obtained in the 66.6% of the treated patients, being grade 1–2 hematological toxicity the most common side effect. Of note, the wide range of the administered activities, the various utilized radiopharmaceuticals (90Y-DOTATOC and/or 177Lu-DOTATATE), the lack of dosimetric studies hamper a clear definition of PRRT potential on meningiomas’ management.

Molecular Imaging of Steroid Receptors in Breast Cancer

“…[141][142][143][144][145] AR-TARGETED IMAGING AR is a steroid receptor expressed in various tissues in males and females, including the breasts, and has important implications in prostate and breast cancer. [146][147][148] AR is abundantly expressed in breast cancer-approximately 70% of all primary breast cancers, 75% to 95% in ER-positive disease, and 10% to 35% in triplenegative (ER-negative, PR-negative, and HER2-negative) disease demonstrate AR positivity. 146,[149][150][151][152] Patients with AR-positive breast cancer have a better prognosis compared with AR-negative breast cancer.…”

Positron Emission Tomography (PET)/Computed Tomography (CT) Imaging in Radiation Therapy Treatment Planning: A Review of PET Imaging Tracers and Methods to Incorporate PET/CT

“…However, they can also be used for imaging breast cancer, medulloblastoma, meningiomas, neuroblastoma, pheochromocytoma, paragangliomas, and primitive neuroectodermal tumors. 43 , 44 , 45 , 46 , 47 …”

Meningiomas and Somatostatin Analogs: A Systematic Scoping Review on Current Insights and Future Perspectives

“…In recent years, theranostics utilizing SSTRs have made its marks in neuro-oncology, including meningiomas, and have recently been recognized by EANO [7]. By using peptide receptor radionuclide therapy (PRRP) with 177Lu-DOTATATE or 90Y-DOTATOC, imaging and therapy is combined, as one radionuclide emits positrons or photons suitable for imaging, while the other emits particles for anti-tumoral effect [55]. Although there are promising preliminary reports for treatment-refractory meningiomas, the efficacy of PRRP is still much unexplored [55][56][57][58][59][60][61].…”

“…By using peptide receptor radionuclide therapy (PRRP) with 177Lu-DOTATATE or 90Y-DOTATOC, imaging and therapy is combined, as one radionuclide emits positrons or photons suitable for imaging, while the other emits particles for anti-tumoral effect [55]. Although there are promising preliminary reports for treatment-refractory meningiomas, the efficacy of PRRP is still much unexplored [55][56][57][58][59][60][61]. Furthermore, several issues need resolving, such as the number of cycles, intervals between the cycles and the optimal activity to be administered [55].…”

“…Although there are promising preliminary reports for treatment-refractory meningiomas, the efficacy of PRRP is still much unexplored [55][56][57][58][59][60][61]. Furthermore, several issues need resolving, such as the number of cycles, intervals between the cycles and the optimal activity to be administered [55]. According to the Norwegian guidelines for meningiomas, some PET-protocols have demonstrated a high sensitivity in detecting meningiomas, though, the diagnostic and clinical use is still limited.…”