Localization of Persistent Air Leaks Using Technetium-99m Technegas SPECT/CT

Effective surgical management of persistent air leaks (PAL) after thoracic surgery depends on their quick and reliable localization, which has been hitherto limited to the intraoperative water submersion test (iWST). We present a case series of 20 patients examined for PAL using technetium-99m Technegas ventilation SPECT/CT (vSPECT).

Technegas was prepared and administered according to the manufacturer's instructions using a Cyclomedica TechnegasPlus generator. SPECT projections were acquired on a Siemens Symbia Intevo Bold gamma camera equipped with a low-energy high-resolution (LEHR) collimator. We reviewed patient records, correlating imaging with intraoperative assessment and the subsequent clinical course.

The median age at the time of surgery was 68.5 years. Surgical indications were pulmonary neoplasm (n = 16, lobectomy/segmentectomy), chronic obstructive pulmonary disease (n = 2, lung volume reduction surgery), solitary fibrous tumor of the pleura (n = 1, fissural pleurectomy), and thymoma (n = 1, thymectomy/pericardectomy). In 10/20 cases, vSPECT successfully located PAL subsequently confirmed by iWST. In 4/20 cases, vSPECT located PAL without confirmation by iWST, however, surgical intervention at the site indicated on vSPECT curbed the leak. In 4/20 cases, PALs identified on vSPECT were managed conservatively as thoracic drainage volumes decreased. In 2/20 cases, vSPECT did not display a PAL; in 1 case, a trocar hernia was found responsible, in another case, revision surgery was deferred, and fistulation resolved without intervention.

Technegas ventilation SPECT/CT appears to be a useful and remarkably accurate modality for the assessment of patients with clinical suspicion of PAL.