Intraoperative gamma probe detection of head and neck paragangliomas with 111In-pentetreotide: a pilot study.
OBJECTIVE
The aim of this study was to assess whether intraoperative radiolocalization of head and neck paragangliomas with 111In-pentetreotide may increase surgical effectiveness, reducing the risk of recurrence.


METHODS
Our study included eight patients with untreated, recently diagnosed paragangliomas (four unilateral and four bilateral tumors of the carotid body). After i.v. injection of approximation 150 MBq 111In-pentetreotide, preoperative somatostatin receptor scintigraphy (SRS) was performed. SPECT of the neck was performed at four hours and planar images of the head and neck were also obtained at four and 24 hours post injection. Scintigraphy was always compared with the results of conventional imaging methods (MRI, angiography and sonography). Intraoperative detection was performed on 11 lesions 24 hours after radiopharmaceutical administration using a handheld gamma probe.


RESULTS
Preoperative SRS showed high radiotracer uptake in all patients. All the intraoperatively detected lesions were radically resected and histologically confirmed to be involved by tumor. No false positive results were recorded. Gamma probe detection revealed a small intracranial extension not detected by other imaging methods in a patient with a paraganglioma of the right carotid, and partial involvement of the carotid artery in another patient. During follow-up (median 3.5 years; range, 4 months-7 years) all patients remained disease free according to all parameters.


CONCLUSIONS
To our knowledge, this is the first experience of radioguided surgery in paraganglioma. Although our study included a relatively small number of patients, we suggest that intraoperative gamma probe detection may be a powerful tool to improve surgical effectiveness.
Filippi
Luca
L
Nuclear Medicine Section, Department of Radiological Sciences, University of Rome "La Sapienza", Rome, Italy. lucfil@hotmail.com
Valentini
Fabrizio Benedetti
FB
Gossetti
Bruno
B
Gossetti
Francesco
F
De Vincentis
Giuseppe
G
Scopinaro
Francesco
F
Massa
Rita
R
D000328:Adult; D000368:Aged; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D007205:Indium Radioisotopes; D008297:Male; D008875:Middle Aged; D010235:Paraganglioma / Q000000981:diagnostic imaging* / Q000473:pathology*; D010865:Pilot Projects; D011859:Radiography; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000032:analysis*; D015899:Tomography, Emission-Computed, Single-Photon
D007205:Indium Radioisotopes; D013004:Somatostatin; C081788:pentetreotide