RT Journal Article SR Electronic T1 Pain Outcomes in Patients with Metastatic Castration-Resistant Prostate Cancer Treated with 223Ra: PARABO, a Prospective, Noninterventional Study JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.123.265557 DO 10.2967/jnumed.123.265557 A1 Palmedo, Holger A1 Ahmadzadehfar, Hojjat A1 Eschmann, Susanne A1 Niesen, Andreas A1 Schönberger, Johann A1 Barsegian, Vahé A1 Liepe, Knut A1 Mottaghy, Felix M. A1 Guan, Rongjin A1 Pinkert, Joerg A1 Sandström, Per A1 Herrmann, Ken YR 2023 UL http://jnm.snmjournals.org/content/early/2023/06/29/jnumed.123.265557.abstract AB 223Ra, a targeted α-therapy, is approved for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) who have bone metastases. In the phase 3 ALSYMPCA study, 223Ra prolonged survival and improved quality of life versus placebo. Our real-world study, PARABO, investigated pain and bone pain–related quality of life in patients with mCRPC and symptomatic bone metastases receiving 223Ra in clinical practice. Methods: PARABO was a prospective, observational, noninterventional single-arm study conducted in nuclear medicine centers across Germany (NCT02398526). The primary endpoint was a clinically meaningful pain response (≥2-point improvement from baseline for the worst-pain item score in the Brief Pain Inventory–Short Form). Results: The analysis included 354 patients, who received a median of 6 223Ra injections (range, 1–6). Sixty-seven percent (236/354) received 5–6 injections, and 33% (118/354) received 1–4 injections. Of 216 patients with a baseline worst-pain score of more than 1, 59% (128) had a clinically meaningful pain response during treatment. Corresponding rates were 67% (range, 98/146) with 5–6 223Ra injections versus 43% (range, 30/70) with 1–4 injections, 60% (range, 60/100) in patients with no more than 20 lesions versus 59% (range, 65/111) in those with more than 20 lesions, and 65% (range, 69/106) in patients without prior or concomitant opioid use versus 54% (range, 59/110) in those with prior or concomitant opioid use. Mean subscale scores (pain severity and pain interference) on the Brief Pain Inventory–Short Form improved during treatment. Conclusion: 223Ra reduced pain in patients with mCRPC and symptomatic bone metastases, particularly in patients who received 5–6 injections. The extent of metastatic disease did not impact pain response.