opportunistic osteoporosis screening on fdg pet/ct scans in breast carcinoma: a comparison with dxa

Obgective(s): reduced bone mineral density is often observed in breast cancer patients. routine pet/ct scans can be used for detection of low bone mineral density. to evaluate prevalence of osteopenia, osteoporosis and fracture risk in pre and post-therapy breast carcinoma patients undergoing 18f-fdg pet/ct scans.methods: in this retrospective study l1-l4 vertebral and femoral neck ct mean hounsfield unit attenuation and their corresponding suvmax values from initial staging and end of treatment fdg pet/ct scans performed in breast carcinoma patients were compared. post chemo ± hormonal therapy fdg pet/ct hu values were also compared to dxa scan t- scores.results: significant increase in prevalence of post chemo ± hormonal therapy osteopenia, osteoporosis and fractures (62%, 18% and 16% vs baseline of 35%, 4% and 9% respectively). cect mean attenuation values of ≤174.6 hu and ≤117.2 hu for detection of osteopenia and osteoporosis with sensitivity of 100% and specificity of 94.2 % for l1-l4 vertebrae, and ≤176.8 hu and ≤117.8 hu for osteopenia and osteoporosis with sensitivity of 100% and specificity 96.4% at femoral necks respectively were suggested. furthermore, mean attenuation values of ≤125.9 hu with sensitivity and specificity of ~100% and 79% and ≤124.8 hu with sensitivity of 100% and specificity ~79.8% were suggested for increased l1-l4 vertebral and femoral neck fractures prevalence/ risk respectively. an associated post chemo ± hormonal therapy decline in vertebral and femoral neck mean suvmax values in range of 14% was also observed.conclusions: baseline and post chemo ± hormonal therapy follow up fdg pet/ct scans allow opportunistic evaluation and can identify a significant number of patients with osteopenia, osteoporosis and patients at increased fracture risk with a high sensitivity and good specificity. they have potential to reduce need for dxa referrals, and also enable early initiation of prophylasix and therapy.