Association for Academic Surgery Technetium-99 m sestamibi imaging : are the results dependent on the reviewer ?

Background: Minimally invasive parathyroidectomy (MIP) is dependent upon accurate preoperative parathyroid localization. We hypothesized that surgeon recognition of subtle differences in radiotracer accumulation would increase the sensitivity of technetium-99m sestamibi imaging and result in more frequent use of MIP. Methods: Technetium-99m sestamibi scans completed at our institution for patients who underwent resection of a solitary parathyroid adenoma were reviewed by a surgeon and a radiologist who were blinded to patient identifying information, prior scan interpretation, and results of the operation. For each scan, the reviewer determined whether there was abnormal radiotracer accumulation and documented its location. Results were correlated with outcome of operation and final pathology. Blinded interpretations of the surgeon and radiologist were compared to each other and to the original radiologic interpretation. Results: From 1994 to 2009, 274 patients with primary hyperparathyroidism (HPT) had sestamibi imaging prior to parathyroidectomy; 149 patients with a single adenoma underwent curative parathyroidectomy and had scans available for review. Seventeen radiologists who reviewed an average of 11 14 scans (range 1⁄4 1e61) completed the original interpretations of the sestamibi imaging. Sensitivity of sestamibi imaging was 86% for the blinded surgeon compared to 75% for the blinded radiologist and 69% for the original radiologists (P < 0.05). There was no difference in the false positive rates (blinded surgeon 1⁄4 5%, blinded radiologist 1⁄4 5%, original radiologists 1⁄4 5%, P > 0.05). Conclusion: Radiologists were less likely to call a scan positive. Surgeon recognition of subtle anatomic asymmetry increases the sensitivity of sestamibi imaging and successful completion of MIP. a 2012 Elsevier Inc. All rights reserved. ry, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH 44109-1998. Tel.: þ1 org (C.R. McHenry). ier Inc. All rights reserved. j o u r n a l o f s u r g i c a l r e s e a r c h 1 7 7 ( 2 0 1 2 ) 9 7e1 0 1 98 1. Background resolution parallel hole collimator and images of the chest Primary hyperparathyroidism (HPT) is common and is caused by a single adenoma in 85% or more of cases [1,2]. When a single adenoma can be localized preoperatively, minimally invasive parathyroidectomy (MIP) can be performed. This is a focused approach with removal of the adenoma without exploration of the other parathyroid glands. It is completed through a 2to 4-cm incision in themidline or directly over the abnormal gland. Intraoperative parathyroid hormone measurements are used to confirm that all hyperfunctioning parathyroid tissue has been removed, limiting the extent of neck exploration [3]. MIP is an outpatient procedure completed under general anesthesia or local anesthesia with intravenous sedation [3]. Over the past decade, MIP has increased in popularity, with reported success rates exceeding 95% [3,4]. The outcome and morbidity ofMIP have been shown to be equivalent to bilateral neck exploration. The advantages of MIP are a smaller incision, reduced operative time, fewer postoperative complications, less neck dissection, and lower cost [3e8]. MIP is considered by many to be the procedure of choice for treatment of primary HPT caused by a single adenoma. Accurate preoperative parathyroid localization is a prerequisite for performing MIP. Technetium-99m sestamibi scintigraphy is the imaging modality of choice for preoperative parathyroid localization in patients with primary HPT [9]. The reported sensitivity and accuracy of sestamibi imaging is variable [10e12]. Accurate interpretation of sestamibi images will optimize the performance and the success rate of MIP. Our hypothesis was that surgeon recognition of subtle differences in radiotracer accumulation would increase the sensitivity of technetium-99m sestamibi imaging and ultimately increase the use of MIP for patients with primary HPT.