Role of 99mTc-Bombesin scan in diagnosis and staging of prostate cancer

Aim of this work was to asses whether a novel Tc-99m labeled Bombesin (BN) can play a clinical role in diagnosis and staging of prostate cancer. 14 patients were studied with trans-rectal ultrasonography-guided biopsy, CT and MRI and with Tc-99m BN Scintigraphy. Five patients were also imaged by In-111 Octreotide (O) scan. All the patients but one were submitted to surgery and final diagnosis was reached by pathology, taken as the gold standard method. Two patients showed benign adenoma and 12 patients showed cancer at biopsy. Tc-99m BN SPECT was positive in all 12 patients with cancer. Four of these patients also showed pelvic focal uptake, referred to inguinal lymph-nodal involvement. MRI and CT provided similar findings in only three cases. Pathologic evaluation after operation confirmed the invasion of nodes in all four subjects. Both Tc-99m BN and In-111 O scans provided normal findings in the two subjects affected by benign adenoma, while In-111 O was positive in only two of three patients with cancer and was always unable to detect nodal invasion. These preliminary data suggest that Tc-99m BN SPECT scan could be useful to detect primary prostate cancer and to reveal loco-regional node involvement.