Page 100 - Fluorescence-guided cancer surgery

98
Chapter 7
ABSTRACT
Background: Identi cation of diseased and normal parathyroid glands during parathyroid surgery can be challenging. The aim of this study was to assess whether near-infrared (NIR) uorescence imaging using administration of a low-dose Methylene Blue (MB) at the start of surgery could provide optical guidance during parathyroid surgery and assist in the detection of parathyroid adenomas.
Methods: Patients diagnosed with primary hyperparathyroidism planned for parathyroid resection were included. Patients received 0.5 mg/kg MB intravenously directly after start of anesthesia. During surgery, NIR uorescence imaging was performed to identify parathyroid adenomas. Imaging results were compared to a previous published feasibility study in which 12 patients received MB after surgical identi cation of the adenoma.
Results: 13 patients were included in the current study. In 10/12 patients with a histologically proven adenoma, the adenoma was uorescent. Mean Signal to Background Ratio (SBR) was 3.1 ± 2.8. Mean diameter of the resected lesions was 17 ± 9 mm (range 5 - 28 mm). Adenomas could be identi ed up to 145 minutes after administration, which was the longest timespan until resection. Interestingly, in 3 patients, a total of 6 normal parathyroid glands (median diameter 2.5 mm) with a SBR of 1.8 ± 0.4 were identi ed using NIR uorescence imaging.
Conclusion: Early administration of low dose MB provided guidance during parathyroid surgery by identifying both parathyroid adenomas and normal parathyroid glands. In patients where di cult identi cation of the parathyroid adenoma is expected, or when normal glands have to be identi ed, administration of MB could improve surgical outcome.