Accuracy of NaF PET/CT scan to detect bone metastases in CRPC.

186 Background: The current standard for imaging Castration Resistant Prostate Cancer (CRPC) is aimed at detecting metastatic lesions to the bones. However, discovery, validation, and implementation of new imaging modalities have fallen considerably behind that of new therapies for this population. Recent studies have shown the NaF PET/CT Scans are significantly more sensitive and accurate in detecting bone lesions than conventionally used Bone Scintigraphy with Technetium-99 (Tc-99). This study conducted retrospective analysis to compare the competence of these two methods for identifying bone metastases. Methods: We conducted a charts review of 613 patients being currently treated with androgen deprivation therapy (ADT) and identified 55 patients who obtained a Na18F PET/CT Scan. Results: The median age was 75.5 years with a range of 52-89, for our cohort. Of these 55 patients, 5 (11.9%) were determined to have metastasis with Tc-99 Bone Scintigraphy alone while 27 (49.1%) were determined to have metastases with NaF Scan (p<0.005). 8 (19%) patients had equivocal findings on Tc-99 Bone Scintigraphy. Therefore, for all of them we performed NaF scan to define a bone metastatic disease that demonstrated in 5 (62.5%) cases of these as having no bone involvement and 3(37.5%) as positive for bone lesions (Table). However, data of NaF scan also indicated 5(9%) patients as having equivocal findings for metastatic disease. Conclusions: According to our data, NaF is more sensitive for detecting bone lesions (11.9 vs. 49.1%). It was also able to delineating equivocal TC-99 Bone Scintigraphy findings, where it deemed 62.5% as negative and 37.5% as positive for bone lesions. NaF PET scan is a feasible option for CRPC for detecting bone metastases, early in disease progression. With coverage of this procedure by Medicare patients have more sensitive and specific tool for early diagnosis and monitoring of treatment of CRPC. [Table: see text]