Assessment of mediastinal involvement in lung cancer with technetium-99m-sestamibi SPECT

This study evaluated the clinical role of SPECT with sestamibi versus CT in the presurgical staging of lung cancer.

Forty-seven consecutive patients (44 men, 3 women; mean age 63.3 yr, range 49-82 yr) with clinical and radiological suspicion of lung cancer were enrolled in this study. Staging procedures including radiography, CT, fiberoptic bronchoscopy and sestamibi SPECT of the thorax. Radionuclide imaging was performed after intravenous injection of 740-925 MBq of sestamibi. In 36 patients a histological diagnosis was made, and these patients were evaluated for the study of mediastinal lymph node involvement.

Mediastinal lymph node involvement was demonstrated in 11 of the 36 patients evaluated. Sestamibi SPECT correctly staged 10 of 11 patients with and 21 of 25 without mediastinal nodes, showing a diagnostic sensitivity of 91% and a specificity of 84%. Computed tomography gave 8 true-positive and 15 true-negative results, with a sensitivity of 73% and a specificity of 60%. Sestamibi SPECT results were also better than those of CT with regard to positive and negative predictive values and accuracy.

The clinical role of sestamibi SPECT can be fully appreciated when the technique is used in selected patients, combined with CT or MRI, or both, to assess mediastinal involvement and avoid any invasive staging procedures.