Radioisotope marking under CT guidance and localization using a handheld gamma probe for small or indistinct pulmonary lesions

Study objectives: A new marking technique was developed to localize small or indistinct pulmonary lesions, involving preoperative radioisotope injection. and intraoperative detection with a handheld gamma probe. Setting: National hospital for respiratory disease. Methods and patients: A technetium suspension (either Tc-99m tin colloid [2 to 4 mCi, 0.5 to 2.5 mL] or Tc-99m phytate [2 mCi, 2.0 mL]) was injected preoperatively in the vicinity of the lesion under CT guidance in 25 patients with small or indistinct pulmonary lesions. A handheld gamma probe (Navigator GPS; Tyco Healthcare Japan; Tokyo, Japan) was used to detect the hot spot where radioactivity was localized during surgery. The lesion marked by the radioisotope then was thoracoscopically resected using endostaplers. Results: The preoperative marking procedure took approximately 30 min. A small pneumothorax and mild intrapulmonary bleeding were observed in two patients and one patient, respectively, but no additional treatment was needed for these complications. The lesion was resected soon after the marking procedure in 21 patients, and on the next day in 4 patients. All lesions were easily identified during. surgery as radioactive hot spots detected by the handheld gamma probe. Thoracoscopic wedge resection was successfully performed in all patients without complications. Conclusion: This new marking technique for small or indistinct pulmonary lesions (radioisotope injection under CT guidance and intraoperative detection with a handheld gamma probe) seems to be safe, reliable, and convenient.