Radioguided lung lesion localization: introducing a fluoroscopy system in a SPECT/CT scan

The purpose was to report our experience in the use of radiotracer localization and resection of small, indistinct, or nonpalpable pulmonary lesions. We developed an innovative technique implementing a fluoroscopy system on a single-photon emission computed tomography/computed tomography (SPECT/CT) scan that allowed to perform CT-guided injection of radiotracer directly on SPECT/CT.

Patients were selected for the radiotracer procedure in presence of difficulties in locating nodules with video-assisted thoracoscopic surgery (VATS). Overall, 0.2 ml of technetium-99m macroaggregated albumin and 0.3 ml of nonionic iodinated contrast were injected under CT guidance. During the VATS procedure, an endoscopic gamma detecting probe was introduced to scan the lung surface. The area of major radioactivity, which matched with the area of the nodule, was resected.

Between January 2016 and October 2018, 37 patients underwent CT-guided radiotracer injection. The mean nodule size was 11 mm. CT nodule morphology characteristics were as follows: 15 nodules were ground glass, 12 were solid, and 10 were partly solid. No significant adverse events occurred. In one patient, the surgeons decided for an open thoracotomy after unsuccessfully VATS. Overall, lobectomy was performed in two patients, segmentectomy in one, and wedge resection in 33 patients. No mortality occurred. The pathological diagnosis was 15 (42%) primary lung cancer, eight (22%) metastases, and 13 (36%) benign lesions.

Radioguided pulmonary nodule localization is a reliable procedure with a high rate of success, minimal complications, and lower risk of failures, with no associated mortality or significant morbidity. Our SPECT/CT system is the first to benefit from the technological improvement with successfully implementation and application of fluoroscopy to SPECT/CT.