Radioimmunoscintigraphy for post-prostatectomy radiotherapy: Analysis of toxicity and biochemical control

4660 Background: To evaluate the role of radioimmunoscintigraphy (RIS) directed against prostate specific membrane antigen (PSMA) [ProstaScint] in influencing post-radical retropubic prostatectomy (RRP) radiotherapy (RT) toxicity and biochemical failure-free survival (BFFS). Methods: The records of 107 consecutive post-RRP patients who underwent RT were reviewed. The group for whom no RIS scan was obtained (Group A, n=54, mean follow-up (FU) 26.7 months) was identified, as was the group for whom RIS was obtained (Group B, n=53, mean FU 21.3 months). Group B was comprised of those who had a RIS/computed tomography (CT) correlation to aid in treatment planning (Subgroup B1, n=40) and those who did not (Subgroup B2, n=13). The acute and late gastrointestinal (GI) and genitourinary (GU) toxicity were reviewed. BFFS curves were constructed, using two successive PSA rises after a nadir to a value > 0.2 ng/mL as the definition of failure. Results: No significant differences in late toxicity were observed between...