A Clinical Trial of TumorGlow® to Identify Residual Disease during Pleurectomy and Decortication.

BACKGROUND: Macroscopic complete resection can provide a select group of malignant pleural mesothelioma (MPM) patients improved survival. During resection, differentiating residual tumor from inflammation or scar can be challenging. In this trial we evaluate near-infrared (NIR) intraoperative imaging using TumorGlow® technology to improve detection of macroscopic residual disease.

METHODS: Twenty subjects were enrolled in an open-label clinical trial of NIR intraoperative imaging with TumorGlow® imaging (NCT02280954). Twenty-four hours prior to pleural biopsy or pleurectomy and decortication (P/D), patients received intravenous indocyanine-green (ICG). All specimens identified during standard-of-care surgery and with NIR imaging underwent histopathologic profiling and correlative microscopic fluorescent tomographic evaluation. For subjects undergoing P/D (n=13), the hemithorax was evaluated with NIR imaging during P/D to assess for residual disease. When possible, additional fluorescent lesions were resected.

RESULTS: Of 203 resected specimens submitted for evaluation, ICG accumulated within 113 of 113 of resected mesothelioma specimens, with a mean signal-to-background fluorescence ratio (SBR) of 3.1 (SD, 2.2-4.8). The mean SBR of benign tissues was 2.2 (SD, 1.4-2.4), which was significantly lower than within malignant specimens (p=0.001). NIR imaging identified occult macroscopic residual disease in 10 of 13 subjects. A median of 5.6 resectable residual deposits per patient (range, 0-11 deposits/patient) with mean size of 0.3cm (range 0.1-1.5cm) were identified.

CONCLUSIONS: TumorGlow® for MPM is safe and feasible. Excellent sensitivity allows for to reliable detection of macroscopic residual disease during cytoreductive surgery.