SAN FRANCISCO — Checking bone mineral density in the forearm as well as the spine and hip in 181 men taking androgen deprivation therapy identified more patients with bone loss than did using densitometry on the spine and hip alone, according to data from a recent study.
Dual-energy x-ray absorptiometry (DXA) scans of the hip and spine have been the accepted standard for osteoporosis screening in men taking androgen deprivation therapy for prostate cancer. The therapy is well known to cause bone loss, Dr. Paul R. Sieber and his associates said.
Interpreting lumbar spine DXA results in these patients can be problematic, so the researchers started adding routine DXA scans of the distal third of the radius to the hip and spine scans of patients using androgen deprivation therapy. They compared results using just the hip and spine scans with results using those plus the forearm scan. The patients had a mean age of 77 years; duration of therapy was up to 10 years.
With the central DXA scans alone, 30 patients (17%) were classified as normal (T score of −1.0 or better), 101 (56%) were osteopenic (T score of −1.0 to −2.5), and 50 (28%) were considered to have osteoporosis (T score less than −2.5). The percentages were rounded.
Adding in the results of the peripheral scan moved seven patients (23% of the normal group) out of the normal range and increased the numbers of osteopenic and osteoporotic patients, the researchers said in a poster presentation at the annual meeting of the International Society for Clinical Densitometry.
With the central plus peripheral DXA scan results, 23 patients (13%) had normal bone density, 93 (52%) were classified as osteopenic, and 65 (36%) had osteoporosis, said Dr. Sieber, of Urological Associates of Lancaster, Penn.
Nine DXA scans of the hip and 42 scans of the spine were uninterpretable, underscoring the need for forearm bone density measurements when screening these patients.
He did not disclose any potential relationships with DXA scan providers or manufacturers, or with companies that make osteoporosis treatments.