Fluorine-18-fluorodeoxyglucose-positron emission tomography evaluation in metastatic bone lesions in lung cancer: Possible prediction of pain and skeletal-related events.

BACKGROUND: Fluorine-18-fluorodeoxyglucose-positron emission tomography (FDG-PET) uptake in primary lesions has been well studied, but little information is available about metastatic bone lesions in patients with lung cancer. The present study was performed to evaluate the relationships between metastatic bone FDG uptake and clinical parameters in patients with lung cancer. METHODS: FDG uptake was evaluated as the maximum standardized uptake (SUVmax) value of each targeted bone lesion, and the bone to primary lesion ratio of SUVmax (B/P ratio) was calculated. Forty-nine patients (27 men and 22 women) with a diagnosis of lung cancer (small cell lung cancer [SCLC], n = 7; non-small cell lung cancer [NSCLC], n = 42) with bone metastasis, and a total of 185 bone metastatic lesions were evaluated. RESULTS: The SUVmax in bone and the B/P ratio were significantly higher in patients with pain and subsequent development of skeletal-related events than in those without pain or skeletal-related events, respectively. In addition, the SUVmax in metastatic bone lesions and the B/P ratio in SCLC were significantly lower than those in NSCLC, despite similar FDG uptake in the primary tumor. CONCLUSION: Our findings suggest that FDG-PET evaluation in metastatic bone lesions could be useful to predict initial pain and subsequent clinical outcomes of local bone status in initially diagnosed lung cancer patients with bone metastasis. In addition, our results suggest that there could be histological differences in the biological activity of bone metastatic lesions in lung cancer, especially between SCLC and NSCLC.

Comparative analysis of PET findings and clinical outcome in patients with primary mediastinal seminoma.

BACKGROUND: Primary mediastinal seminoma is a rare neoplasm. Cisplatin-based chemotherapy is the standard treatment, but management of post-chemotherapy seminoma residuals is still controversial. We encountered four cases of primary mediastinal seminoma and reviewed the clinical characteristics and outcomes, focusing on tumor size and F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) findings after chemotherapy. METHODS: A retrospective review was performed of four consecutive patients with primary mediastinal seminoma treated in our institution between 2006 and 2010. All patients were young adult males with a median age of 31.3 years (range: 20-46 years). All patients were treated with three to four cycles of a combination of cisplatin, bleomycin, and etoposide, and FDG-PET was performed after chemotherapy. RESULTS: The response to chemotherapy was good in all patients. After chemotherapy, the findings of the FDG-PET were negative in three subjects. Two of the patients, with tumors measuring over 30 mm, underwent surgical resection for the residual mass and revealed necrotic tissues and no viable cells. A third patient remained stable without salvage surgery. The size of the residual mass in the remaining patient was less than 30 mm, but the FDP-PET result was positive and the mass considered inoperable because of the involvement of large vessels. Subsequently, radiotherapy was added for the residual tumor, but disease progression was seen seven months after the initiation of chemotherapy. CONCLUSIONS: FDG-PET findings after chemotherapy could be useful as a tool for the prediction of viable residual tumor in post chemotherapy residual mediastinal seminoma.