Role of gamma probes in performing minimally invasive parathyroidectomy in patients with primary hyperparathyroidism: optimization of preoperative and intraoperative procedures

Abstract

Objective: In the last decade, surgery of primary hyperparathyroidism (HPT) due to a solitary adenoma has moved on from the traditional wide bilateral neck exploration (BNE) to more limited approaches such as unilateral neck exploration and minimally invasive parathyroidectomy. Design: To define the role of intraoperative gamma probe and injection of a low 99m Tc-MIBI dose in performing minimally invasive radio-guided surgery (MIRS) in HPT patients with a solitary parathyroid adenoma. Methods: From September 1999 to July 2002, 214 patients with primary HPT entered the study. All patients were preoperatively investigated by a 99m Tc-pertechnetate/MIBI subtraction scan and high-resolution neck ultrasound. The intraoperative technique we developed differs from other previously described techniques being based on the injection of a low (37 MBq) MIBI dose in the operating theatre a few minutes before the beginning of intervention. Results: On the basis of scan/ultrasound findings 147 patients were selected for a MIRS and 144 of them (98%) were successfully treated by this approach: a solitary parathyroid adenoma was removed through a small 2-2.5 cm skin incision with a mean operative time of 35 min, and a mean hospital stay of 1.2 days. In the other 67 patients with scan/ultrasound evidence of concomitant nodular goiter (n ¼ 45) or multi-gland disease (n ¼ 13) or with a negative scan (n ¼ 9), the gamma probe was utilized during a traditional BNE. A low 37 MBq MIBI dose proved to be sufficient to perform a MIRS; moreover it delivered to the patient and surgeon a low, negligible, radiation exposure dose. Conclusions: The combination of a 99m Tc-pertechnetate/MIBI subtraction scan and neck ultrasound appears to be an accurate imaging protocol in selecting primary HPT patients as candidates for a MIRS. A MIBI dose as low as 37 MBq injected in the operating theatre just before the start of surgery appears to be adequate to perform radio-guided surgery.

Kinetics of intraoperative fluorescence diagnosis of parathyroid glands

“…Rubello et al (14) performed minimally invasive radioguided surgery in preselected patients with primary HPT with a success rate of 97.9%. Using a hand-held gamma collimated probe, which was inserted through a 2 -2.5 cm skin incision, even ectopic PTG adenoma in the upper mediastinum and at the carotid bifurcation, as well as glands deep in the para-oesophageal/ para-tracheal space, was rapidly found (14). In a prospective series by Nichol et al (16), radio-guided surgery for secondary and tertiary HPT was associated with a cure rate of 100%.…”

Original technique for preoperative preparation of patients and intraoperative localization of parathyroid adenomas

“…Indeed, to confirm the identification and removal of the hyperfunctional parathyroid it is accepted as adequate an ex vivo radioactivity count of the adenoma 20% or 40% greater than the value of the postexcisional background radioactivity, in association or not with intraoperative measurement of PTH, depending on the protocols (10,11). Furthermore, according to some authors, the count of radioactivity is so reliable as to make unnecessary the intraoperative PTH assay or other confirmatory examinations (12,13).…”

“…Other authors described a separate day protocol whereas preoperative double-tracer (Tc99 m -pertechnetate and Tc99 m -sestaMIBI) subtraction scintigrafy is performed several days before the surgery to identify the adenoma (4). On the day of the surgery, some minutes before the beginning of the operation, patients are injected with low dose of Tc99 m -sestaMIBI (37 MBq) (6 radiation due to radiotracer uptake of the surrounding tissues, above all thyroid parenchyma.…”

Minimally Invasive Parathyroidectomy

“…2,[6][7][8][9][10] Improvements in preoperative parathyroid imaging (using computed tomography, magnetic resonance imaging, and sestamibi scans), the development of the intraoperative handheld gamma probe, and intact parathyroid hormone (PTH) assays served as an impetus for minimally invasive parathyroidectomy (MIP). Various studies have shown that MIP can be successfully performed with preoperative sestamibi scanning and intraoperative radioguidance 1,6,[11][12][13][14] without the need to measure PTH levels. 1,5,11,14 Advantages of MIP include decreased disruption of normal tissue, smaller incisions, reduced operative times, the option of performing the procedure under local anesthesia, lower complication rates and hospital costs, and same-day discharge.…”

“…Various studies have shown that MIP can be successfully performed with preoperative sestamibi scanning and intraoperative radioguidance 1,6,[11][12][13][14] without the need to measure PTH levels. 1,5,11,14 Advantages of MIP include decreased disruption of normal tissue, smaller incisions, reduced operative times, the option of performing the procedure under local anesthesia, lower complication rates and hospital costs, and same-day discharge. 2,3,6,11,15 Many investigators have demonstrated cure rates of greater than 90% in appropriately selected patients.…”