99mTc-Tetrofosmin Scintigraphy in Lung Cancer Staging and Follow-up Evaluations

Gianfranco Buccheri, M.D.; Alberto Biggi, M.D.; Domenico Ferrigno, M.D. and Antonella Francini, M.D.

* From the Lung Unit (Drs. Buccheri and Ferrigno), and the Service of Nuclear Medicine (Drs. Biggi and Francini) of the A. Carle and S. Croce Hospitals ("Azienda Ospedaliera S. Croce e Carle"), I-12100 Cuneo, Italy.

KEY WORDS:
Lung cancer, staging assessment, treatment response evaluation, computed tomography, 99mTc-tetrofosmin scintigraphy.

Reprint requests and communications regarding the manuscript: Gianfranco Buccheri, MD, Corso Barale, 9 - 12011 Borgo San Dalmazzo (CN), Italy, Tel.: +39.0171.441733 or +39.0171.441777, Fax: +39.0171.611597 or +39.0171.441764, Email: buccheri@culcasg.org

The Authors have no financial interest in the subject discussed in this paper. They all have sufficiently participated in the work and in the manuscript preparation. The local committee on human research approved this study.

ABSTRACT
Study Objectives – 99mTc-tetrofosmin has recently emerged as a new radiopharmaceutical for cancer visualization. In this study, we investigate its ability to assess lung cancer dissemination and progression.

Design – Prospective study. A 99mTc-tetrofosmin scan was incorporated into the pretreatment and posttreatment diagnostic workup of lung cancer in the years 1998 and 1999.

Setting – Second referral institution for a province of 500,000 inhabitants.

Patients – Sixty-one patients, strongly suspected of lung cancer, were photoscanned; 21 of them were re-scanned after completion of their front line treatment. Eleven patients were eventually operated upon, and 3 others underwent mediastinoscopy.

Interventions – Both planar and SPECT thoracic views were obtained. Images for the whole body were also acquired.

Results – All 57 patients whose lung cancer was pathologically confirmed showed accumulation of the radiotracer (100% sensitivity). However, three of the 4 non-malignant lesions were also 99mTc-tetrofosmin positive. 99mTc-tetrofosmin scan was highly sensitive for the detection of the T0-T2 disease (97% sensitivity), and highly specific for the N0-N1 disease (83% specificity). In the 16 pathologically staged mediastina, sensitivity, specificity and accuracy rates were 73%, 100%, and 81%, respectively. 99mTc-tetrofosmin scan correctly detected most skeleton (9 of 10) and brain (5 of 7) metastases. The treatment response evaluation made with 99mTc-tetrofosmin corresponded to the clinical estimate in almost half of the sample.

Conclusions – This study shows that 99mTc-tetrofosmin scan is a relatively accurate method for lung cancer evaluation. Our preliminary data excludes, however, that noninvasive diagnostic efficiency might be dramatically increased by a scintigraphy with 99mTc-tetrofosmin. More studies are needed for a better understanding of the real value of this technique.