The bone scan flare phenomenon in non-small-cell lung cancer.

PURPOSE: The bone scan flare phenomenon, defined as an increase in the number or intensity of bone lesions with subsequent improvement while the patient is receiving chemotherapy, has been described in solid tumors including breast cancers and small-cell lung cancers. The purpose of this study was to verify the existence of the bone scintigraphic flare phenomenon in patients with non-small-cell lung cancer (NSCLC) during chemotherapy and thus determine the utility of bone scintigraphy in the follow-up of these patients.

MATERIALS AND METHODS: Thirty-three patients with NSCLC with bone metastases and who had been treated with chemotherapy were included in the study. The outcome of bone scintigraphy was compared with that in other neoplastic sites.

RESULTS: The flare phenomenon was considered likely in 8 of the 33 patients. It was confirmed in two patients, invalidated in four, and remained doubtful in two.

CONCLUSIONS: The bone flare phenomenon occurs in NSCLC. It renders bone scintigraphy less useful in the evaluation of tumoral response in the patients in whom it is considered likely.