Diffusely increased uptake by thoracic vertebrae on bone scintigraphy in midcourse of lung cancer irradiation: a case report.

Bone scintigraphy performed on a patient during the middle of radiation therapy for an inoperable left lung malignancy showed diffusely increased uptake in the thoracic vertebrae and relatively increased uptake in the ribs of the left thorax. This bone scan finding is apparently a transient phenomenon that occurs in response to irradiation and eventually leads to photon deficiency or photopenia of the vertebrae. However, this transiently increased uptake of the thoracic spine, compared with uptake in the lumbar spine, mimics diffusely decreased uptake or photopenia of the lumbar vertebrae and may be misinterpreted as an effect of irradiation of the abdominal region. In the case of asymmetric uptake between the thoracic and lumbar spine, a carefully taken history of the timing and location of irradiation is necessary to avoid misinterpretation.