Evaluation of pentavalent Tc-99m DMSA scintigraphy in small cell and nonsmall cell lung cancers

The purpose of this study was to evaluate the clinical usefulness of Tc-99m (V) DMSA in patients suspected of lung cancer and determine whether this agent may have value in differentiation between small cell (SCLC) and non-small cell (NSCLC) lung carcinoma.

Thirty-six patients with clinical and radiological suspicion of primary lung carcinoma were injected 450-600 MBq of Tc-99m (V) DMSA intravenously. Whole body and planar anterior, posterior thorax images were obtained 4-5 h after injection of the radioactive complex.

Histopathological results confirmed 23 NSCLC, 10 SCLC and 1 metastatic lung carcinoma and 2 lung abscess. Nineteen of the 23 (82%) NSCLC and all of the 10 (100%) SCLC cases showed Tc-99m (V) DMSA uptake. Single metastatic lung cancer also accumulated radiotracer. Lung abscess did not show uptake. Lesion/Nonlesion (L/N) ratio of SCLC (1.59 +/- 0.32) and NSCLC (1.43 +/- 0.19) tumour types did not show statistical difference (p > 0.05). Tc-99m (V) DMSA whole body imaging also showed bone metastases.

Tc-99m (V) DMSA is a noninvasive and cheap imaging method to detect malignant lung cancers and their bone metastases but, differentiation of SCLC and NSCLC is not possible.