RT Journal Article SR Electronic T1 The Placorhen Study: A Double-Blind, Placebo-Controlled, Randomized Radionuclide Study with 186Re-Etidronate in Hormone-Resistant Prostate Cancer Patients with Painful Bone Metastases JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1150 OP 1156 VO 43 IS 9 A1 Shiuw H. Han A1 John M.H. de Klerk A1 Suzy Tan A1 Alfred D. van het Schip A1 Bert H. Derksen A1 Aalt van Dijk A1 Cas L.J.J. Kruitwagen A1 Geert H. Blijham A1 Peter P. van Rijk A1 Bernard A. Zonnenberg YR 2002 UL http://jnm.snmjournals.org/content/43/9/1150.abstract AB 186Re-1,1-hydroxyethylidene diphosphonate (etidronate) can be used for the palliative treatment of metastatic bone pain. A randomized, placebo-controlled study using 186Re-etidronate was conducted on end-stage prostate cancer patients with metastatic bone pain. Methods: Pain relief was assessed using an electronic diary containing questions reflecting the multidimensional character of chronic pain. The diary was marked twice daily for a maximum of 14 wk (2 wk before and 12 wk after the injection). Pain response was determined using a specific decision rule in which pain intensity, medication index, and daily activities were the core determinants. A positive response day was defined as a day on which pain intensity was reduced ≥25% compared with baseline values, while medication index and daily activities were at least constant, or on which pain intensity was reduced < 25% and medication index or daily activities improved ≥25%, without worsening of the remaining factor. The total response (%) was defined as the number of positive response days divided by the number of days of follow-up. Results: Of the 111 included patients, 79 were evaluable (43 186Re-etidronate, 36 placebo). Thirty-two patients were excluded from the analysis because of incomplete datasets. The total response of the patients treated with 186Re-etidronate varied from 0% to 96% (mean, 27%, or 23/84 d). In the placebo group, the total response varied from 0% to 80% (mean, 13%, or 11/84 d; Mann-Whitney U test, P < 0.05). The number of patients who requested radiotherapy was higher in the placebo group (67%) than in the 186Re-etidronate group (44%) (relative risk, 1.51; Fisher’s exact test, P = 0.069). Conclusion: This randomized controlled trial confirmed that, compared with placebo, 186Re-etidronate resulted in a significantly longer pain response in the treatment of bone pain from metastasized prostate cancer.