Bone scintigraphy evaluated in diagnosing and staging Langerhans' cell histiocytosis and related disorders

An analysis of patients with proven Langerhans' cell histiocytosis (LCH) was undertaken with the aim of evaluating the role of bone scintigraphy in the diagnosis and staging of LCH.

Radiographic skeletal surveys and whole-body bone scintigraphy study results were reviewed for all patients treated at the Mayo Clinic in Rochester, Minnesota during 1965-1994 with histologic proven LCH. All available studies were then reported in a randomized and blinded fashion.

Of the 73 patients with the histologic diagnosis, 56 (76%) had a definite lesion reported on radiographs and subsequent biopsy-proven bone involvement. For this population, the sensitivity and specificity of radiographic survey were 100% and 61%, respectively, compared to 91% and 55% for bone scintigraphy. Solitary bone lesions were reported on 21 radiographic surveys and 24 bone scintigrams. For solitary lesions, radiograph sensitivity and specificity were 95% and 73%, respectively, compared to 88% and 77% for bone scintigraphy. Bone scintigraphy receiver operating characteristic curves showed the region of greatest diagnostic accuracy to be skull, facial bones and mandible (88% sensitivity, 52% specificity). Radiation dosimetry to adult reproductive organs was less favorable for radiographic skeletal survey compared to bone scintigraphy.

Our results support the use of radiographic skeletal survey in the initial diagnosis of LCH. Bone scintigraphy may have a role in monitoring a patient's progress in which the initial scintigram and radiographic survey show good correlation.