Assessing Under-utilization of Na-18F PET/CT for Oncologic Bone Imaging at a Single Academic Medical Center

1773 Objectives Despite Na-18F PET/CT being a more sensitive and more specific imaging study than 99mTc MDP for osteoblastic metastases, it remains an under-utilized imaging modality in clinical practice. Given that NOPR found that the majority of Na18F PET/CT studies were performed for prostate, breast and lung cancers, under-utilization may result from the lack of knowledge by specific referring physicians about the possibility of NOPR coverage in certain patients as well as the practical diagnostic and workflow advantages of Na-18F PET/CT. The objective of this study was to assess the relative utilization rates of 99mTc MDP whole-body bone scintigraphy and Na-18F PET/CT studies for oncologic bone imaging at a single medical center environment and to identify opportunities for increasing disease-specific utilization of NaF PET/CT. Methods This is a retrospective evaluation of the ordering patterns related to oncologic bone imaging over a 30-month period with respect to 99mTc MDP whole-body bone scintigraphy and Na-18F PET/CT. The cancer type and referring physician specialty associated with these oncologic bone imaging studies were also evaluated. Whenever applicable, nomenclature and categorization similar to the NOPR effort was used. Results Overall, Na18F PET/CT represented less than 1% of all oncologic bone imaging studies performed during a 30-month period when compared with 99mTc MDP whole body bone scintigraphy. Only 1% of all patients referred for oncologic bone imaging during this period were specifically sent for Na-18F PET/CT imaging. With regard to 99mTc MDP whole-body studies, 42% were ordered for breast cancer, 18% for prostate cancer, 8% for other genitourinary cancers, 2% for lung cancer and 30% for all other cancers. In terms of Na-18F PET/CT studies, 68% were ordered for prostate cancer, 4% for breast cancer, and 28% for all other cancers. The vast majority (>85%) of all oncologic bone imaging studies are ordered by medical oncologists/hematologists in our medical center environment. Conclusions Our findings demonstrate that there is marked under-utilization of Na-18F PET/CT for oncologic bone imaging when compared with whole-body MDP imaging. Within our institution, there is relatively few breast cancer patients referred for Na-18F PET/CT whereas breast cancer patients constitute the majority of oncologic whole body 99mTc MDP studies. On the other hand, prostate cancer patients make up the majority of referrals for Na-18F PET/CT whereas less than 20% of 99mTc MDP studies are routinely performed in prostate cancer patients. There were no instances of Na-18F PET utilization for other genitourinary cancers or lung cancers despite that these cancers represented 10% of all 99mTc MDP studies. These findings have also identified specific referring physician populations and specific cancer populations which may help to better utilize Na-18F PET through targeted education by nuclear medicine physicians. It is likely that future efforts will identify existing and perceived barriers to the expanded clinical use of Na-18F PET/CT coinciding with generating the evidence to justify future appropriate referrals.