Long-term follow-up of111 In-capromab pendetide (ProstaScint) scan as pretreatment assessment in patients who undergo salvage radiotherapy for rising prostate-specific antigen after radical prostatectomy for prostate cancer

• Published in: International journal of radiation oncology, biology, physics Vol. 67; no. 3; pp. 834 - 840
• Main Authors: Nagda, Suneel N., M.D, Mohideen, Najeeb, M.D, Lo, Simon S., M.D, Khan, Usman, B.S, Dillehay, Gary, M.D, Wagner, Robert, M.D, Campbell, Steven, M.D, Flanigan, Robert, M.D
• Format: Journal Article
• Language: English
• Published: 2007
• Subjects: Hematology, Oncology and Palliative Medicine; Radiology; Capromab pendetide; Recurrence; Salvage radiotherapy; ProstaScint; Prostate cancer
• DOI: 10.1016/j.ijrobp.2006.09.026
• ISSN: 0360-3016

Purpose: To evaluate the long-term failure patterns in patients who underwent an111 In-capromab pendetide (ProstaScint) scan as part of their pretreatment assessment for a rising prostate-specific antigen (PSA) level after prostatectomy and subsequently received local radiotherapy (RT) to the prostate bed. Methods: Fifty-eight patients were referred for evaluation of a rising PSA level after radical prostatectomy. All patients had negative findings for metastatic disease after abdominal/pelvis imaging with CT and isotope bone scans. All patients underwent a capromab pendetide scan, and the sites of uptake were noted. All patients were treated with local prostate bed RT (median dose 66.6 Gy). Results: Of the 58 patients, 20 had biochemical failure (post-RT PSA level >0.2 ng/mL or a rise to greater than the nadir PSA), including 6 patients with positive uptake outside the bed (positive elsewhere). The 4-year biochemical relapse-free survival (bRFS) rates for patients with negative (53%), positive in the prostate bed alone (45%), or positive elsewhere (74%) scan findings did not differ significantly ( p = 0.51). The positive predictive value of the capromab pendetide scan in detecting disease outside the bed was 27%. The capromab pendetide scan status had no effect on bRFS. Those with a pre-RT PSA level of <1 ng/mL had improved bRFS ( p = 0.003). Conclusion: The capromab pendetide scan has a low positive predictive value in patients with positive elsewhere uptake and the 4-year bRFS was similar to that for those who did not exhibit positive elsewhere uptake. Therefore, patients with a postprostatectomy rising PSA level should considered for local RT on the basis of clinicopathologic factors.