⁶⁸Ga-DOTANOC PET/CT for Baseline Evaluation of Patients with Head and Neck Paraganglioma

Abstract

The purpose of this study was to evaluate the role of 68 Ga-labeled DOTANOC PET/CT for baseline evaluation of patients with head and neck paragangliomas (HNPs). Methods: The data for 26 patients (mean age 6 SD, 34.3 6 10.4 y; 50% men) with known or suspected HNPs who underwent 68 Ga-DOTANOC PET/CT for staging were retrospectively analyzed. PET/CT was performed after intravenous injection of 132-222 MBq of 68 Ga-DOTANOC. The images were evaluated by 2 experienced nuclear medicine physicians in consensus, both qualitatively and quantitatively. The PET/CT findings were grouped as HNPs, paraganglioma at other sites (non-HNPs), and metastatic disease. The size and maximum standardized uptake values (SUVmax) were measured for all lesions. All of the patients also underwent whole-body 131 I-metaiodobenzylgunanidine ( 131 I-MIBG) scintigraphy and conventional imaging (CT/MR imaging) of the head and neck region. Their results were compared with those of 68 Ga-DOTANOC PET/CT. Results: 68 Ga-DOTANOC PET/CT findings were positive in all 26 patients, and 78 lesions were detected. PET/CT imaging demonstrated 45 HNPS, 10 non-HNPs, and 23 metastatic sites. Fifteen patients (57.6%) had more than one site of disease on PET/ CT. Among 45 HNPs, 26 were carotid body tumors (CBTs), 15 glomus jugulare, 3 glomus tympanicum, and 1 laryngeal paraganglioma. A positive correlation was seen between size and SUVmax of HNPs (r 5 0.323; P 5 0.030). The SUVmax of the CBTs was higher than that of jugulotympanic paragangliomas (P 5 0.026). No correlation was seen between size and SUVmax (r 5 0.069; P 5 0.854) of non-HNPs. The size and SUVmax of non-HNPs were significantly less than those of HNPs (P 5 0.029 and 0.047, respectively). 131 I-MIBG scintigraphy showed only 30 of the 78 lesions and was inferior to PET/CT (P , 0.0001). Conventional imaging (CT/MR imaging) was positive for 42 of 49 head and neck lesions and was inferior to PET/CT on direct comparison (P 5 0.015). A combination of CT/MR imaging and 131 I-MIBG scintigraphy detected only 53 of 78 (67.9%) lesions and was also inferior to PET/CT (P , 0.0001). Conclusion: 68 Ga-DOTANOC PET/CT is useful for the baseline evaluation of patients with HNPs and can demonstrate synchronous paragangliomas at other sites and distant metastases. It is superior to 131 I-MIBG scintigraphy and conventional imaging (CT/MR imaging) for this purpose.

Could 68Ga-somatostatin analogues replace other PET tracers in evaluating extra-adrenal paragangliomas?

“…A recent retrospective study of Sharma et al evaluated 26 patients with H&N PGL by using 68 Ga-DOTANOC PET/CT. This imaging method was positive in all 26 patients being very useful for the baseline evaluation of patients with H&N PGL and demonstrating synchronous PGLs at other sites and distant metastases with superior diagnostic accuracy compared to 131 I-MIBG scintigraphy and conventional imaging [13], confirming the preliminary results of the same group reported in a pilot study about 68 Ga-DOTANOC PET/CT on 5 H&N PGLs [14].…”

“…Recent articles in the literature assessed the diagnostic accuracy of somatostatin receptor PET/CT using different somatostatin analogues labelled with 68 Ga ( 68 Ga-DOTATATE, 68 Ga-DOTANOC and 68 Ga-DOTATOC) in patients with extraadrenal PGL [8][9][10][11][12][13][14][15][16][17], based on the increased expression of somatostatin receptors in PGL neoplastic cells [18].…”

Functional Imaging Signature of Patients Presenting with Polycythemia/Paraganglioma Syndromes

“…68 Ga-DOTATATE PET/CT was recently introduced into PPGL imaging and has shown excellent results in the patient groups evaluated thus far, which mainly include those with sporadic and SDHBrelated metastatic PPGL as well as head and neck PGLs (13,(29)(30)(31)(32)(33)(34).…”

The Challenges of Treating Paraganglioma Patients with 177Lu-DOTATATE PRRT: Catecholamine Crises, Tumor Lysis Syndrome and the Need for Modification of Treatment Protocols

“…Ga-DOTATATE PET/CT sensitivity of 80 % in the detection of pheochromocytomas and paragangliomas, superior to 123 I-MIBG [11], and Naswa Ga-DOTANOC in 26 head and neck paraganglioma patients [13]. 177 Lu-DOTATATE has been found to be superior to other radiolabeled somatostatin analogs for use in PRRT because of its high somatostatin receptor subtype 2 binding, superior tumor uptake and lower toxicity profile due to the lower tissue penetration range of the 177 Lu radioisotope [9,14].…”