68Ga-PSMA-11 PET/CT imaging in elderly patients with newly-diagnosed prostate cancer, with and without pre-imaging biopsy

Abstract

Abstract Purpose to assess the value of staging 68Ga-PSMA-11 PET/CT in elderly patients with biopsy-proven or high clinical suspicion of prostate cancer (PCa). Methods 100 consecutive patients 80 years of age and older referred for 68Ga-PSMA-11 PET/CT with biopsy proven high-risk PCa (n = 66 pts) or high clinical suspicion of clinically relevant PCa without biopsy (n = 34 pts) were enrolled. Clinical parameters, biopsy results (when performed), 68Ga-PSMA-11 PET/CT findings and treatment approach wererecorded. Patients were categorized to those that had a pre-imaging biopsy B(+) and those that did not B(-). Results All patients had a PSMA-avid disease including the 34 B(-) patients in whom a focal "hot" lesion was identified in the prostate suggestive of the primary tumor lesion. Based on 68Ga-PSMA-11 PET/CT, 36 patients had a localized disease 25 patients had a locally advanced disease and 39 had an advanced disease. Lesions requiring a special clinical attention were identified. B(-) patients were older (median age 87 vs. 82, Pv < 0.01), with worse performance status (Pv < 0.01), and higher PSA levels (median 57 vs. 15.4 ng/ml, Pv < 0.01). Staging was not different in B(+) and B (-) patients, but the latter showed a trend for higher rates of bone metastases (47.1% vs. 28.8%) and overall advanced disease (50% vs. 33.3%). All Patients with advanced disease but one (38/39), received hormonal therapy, whether they had a pre-imaging biopsy or not. Focusing on the 16 B (-) patients showing advanced disease on 68Ga-PSMA-11 PET/CT and receiving hormonal therapy, in 92.3% patients decrease in PSA levels was achieved (mean ∆PSA, 95.6%, IQR, 95.0-98.2%) and in 88.9% follow-up 68Ga-PSMA-11 PET/CT showed improvement or stable disease. Conclusion Elderly patients often referred for 68Ga-PSMA-11 PET/CT when diagnosis of high-risk PCa is biopsy-proven or without a pre-imaging biopsy, when presenting with clinically suspected PCa. 68Ga-PSMA-11 PET/CT findings allow for accurate staging and assist in guiding treatment. Many elderly patients may benefit same treatment applied in younger patients. If did not undergo biopsy, treatment may be chosen based on imaging findings alone.