No abstract

9101 Background: Radiofrequency Ablation (RFA) can destroy tissue in a defined area. Single institutions have reported that RFA can reduce pain from bone metastases. To confirm this, the American College of Radiology Imaging Network (ACRIN) completed a multicenter study of RFA for bone metastases. Methods: Eligible patients had bone pain in one dominant site: tumor size < 8 cm, and location > 1 cm from the spinal cord or cauda equina. RFA was performed under CT guidance. The Memorial Pain Assessment Card was used prior to RFA and repeated daily for two weeks, and at 1 and 3 months after RFA. AEs were recorded in addition to four different pain assessment measures: pain relief, patient mood, pain intensity, and pain severity. Results: Fifty-six patients had RFA at 9 centers. Metastatic sites were pelvis (24), chest wall (19), thoracolumbar spine (8), and extremities (5). Six out of 56 patients experienced at least one adverse event of grade 3 or higher, yielding an AE rate of 10.7% (95%CI is 2.6% to18.8%). AEs attributed directly to RFA were nerve injury in 2 patients. Of the 56 participants, 43 completed the 1 month follow-up and 33 completed the 3 month follow-up. At the time of this analysis, assuming that missing data were missing at random and after adjusting for all covariates, RFA showed significant effect in reducing pain at 1 and 3 month follow-up for all 4 pain assessment measures. The average increase in pain relief from pre-RFA to 1 month follow-up is 26.4 (P<0.0001) and the increase from pre-RFA to 3 month follow-up is 17.2 (P=0.003). The average increase in mood from pre-RFA to 1 month follow-up is 21.5 (P<0.0001) and the increase from pre-RFA to 3 month follow-up is 16.3 (P=0.001). The average decrease in pain intensity from pre-RFA to 1 month follow-up is 25.9 (P<0.0001) and the decrease from pre-RFA to 3 month follow-up is 13.0 (P=0.02). The odds of being in lower pain severity at 1 month follow-up is 12.6 (P<.0001) times higher than that at pre-RFA, and the odds at 3 month follow-up is 7.1 (P<0.0001) times higher than that at pre- RFA. Conclusions: This cooperative group trial confirms that RFA can safely palliate pain due to bone metastases. ACRIN receives funding from the National Cancer Institute through the grants U01 CA079778 and U01 CA080098. No significant financial relationships to disclose.

BACKGROUND:The study was conducted to determine whether radiofrequency ablation (RFA) can safely reduce pain from osseous metastatic disease. METHODS: The single-arm prospective trial included patients with a single painful bone metastasis with unremitting pain with a score >50 on a pain scale of 0-100. Percutaneous computed tomography-guided RFA of the bone metastasis to temperatures >60 C was performed. Endpoints were the toxicity and pain effects of RFA

18F-fluoride PET quantitatively images bone metabolism and may serve as a pharmacodynamic assessment for systemic therapy such as dasatinib, a potent SRC kinase inhibitor, with activity in bone. Methods This was an imaging companion trial (American College of Radiology Imaging Network [ACRIN] 6687) to a multicenter metastatic castration-resistant prostate cancer (CRPC) tissue biomarker–guided therapeutic trial (NCT00918385). Men with bone metastatic CRPC underwent 18F-fluoride PET before and 12 weeks after initiation of dasatinib (100 mg daily). Dynamic imaging was performed over a 15-cm field of view for trial assessments. The primary endpoint was to determine whether changes in 18F-fluoride incorporation in tumor and normal bone occurred in response to dasatinib. Other endpoints included differential effect of dasatinib between 18F-fluoride incorporation in tumor and normal bone, 18F-fluoride transport in bone metastases, correlation with progression-free survival (PFS), prostate-specific antigen, and markers of bone turnover. Results Eighteen participants enrolled, and 17 underwent interpretable baseline 18F-fluoride PET imaging before initiation of dasatinib. Twelve of 17 patients underwent on-treatment PET imaging. Statistically significant changes in response to dasatinib were identified by the SUVmaxavg (average of maximum standardized uptake value [SUVmax] for up to 5 tumors within the dynamic field of view) in bone metastases (P = 0.0002), with a significant differential 18F-fluoride PET response between tumor and normal bone (P < 0.0001). Changes in 18F-fluoride incorporation in bone metastases had borderline correlation with PFS by SUVmaxavg (hazard ratio, 0.91; 95% confidence interval, 0.82–1.00; P = 0.056). Changes by SUVmaxavg correlated with bone alkaline phosphatase (P = 0.0014) but not prostate-specific antigen (P = 0.47). Conclusion: This trial provides evidence of the ability 18F-fluoride PET to delineate treatment response of dasatinib in CRPC bone metastases with borderline correlation with PFS.