Radioguided occult lesion localization for minimally invasive parathyroidectomy: technical consideration and feasibility Seyfettin Ilgan a , Serdar Ozbas b , Banu Bilezikci c , Tugba Sengezer a , Oguz Ugur Aydin b , Alptekin Gursoy d and Savas Kocak b Purpose of the report Minimally invasive parathyroidectomy (MIP) constitutes one of the main surgical approaches for the patient with primary hyperparathyroidism (PHPT) caused by a single parathyroid adenoma. The purpose of the study was to investigate the feasibility of radioguided occult lesion localization (ROLL) for MIP and the potential effects of the method in histopathologic evaluation. Materials and methods Twenty-two patients, diagnosed with PHPT biochemically and candidates for surgery, underwent ROLL-guided MIP (ROLL-MIP). Parathyroid adenomas were searched for and identified with the guidance of an intraoperative gamma probe. The final diagnosis was confirmed by histopathologic analysis. All specimens were analyzed for the presence of parenchymal hemorrhage, congestion, neutrophil leukocyte infiltration, necrosis, cystic degeneration, subcapsular hematoma, subcapsular fibrin/neutrophil leukocyte infiltration, and disarray of the fibrous capsule of adenoma. Results All injected lesions were effectively located over the skin with very high count rates depending on the injected activity and location of the lesion. Serum calcium and parathyroid hormone (PTH) levels normalized in all patients and stayed within the normal range during the follow-up period. None of the patients who underwent ROLL-MIP suffered temporary or permanent recurrent laryngeal nerve injuries. The mean operative time was 23 ± 7 min. Parenchymal hemorrhage, congestion, subcapsular hematoma, and fibrin/neutrophil leukocyte infiltration were common histopathologic features. Conclusion The use of ROLL-MIP in patients with PHPT due to a single parathyroid adenoma in the neck is technically safe and effective. It is more valuable in scintigraphy-negative patients when parathyroid adenoma is either demonstrated on ultrasonography by typical findings or confirmed by PTH washout. The ROLL-MIP technique does not impair the postoperative histopathologic examination of the parathyroid glands. Nucl Med Commun 35:1167–1174 © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Nuclear Medicine Communications 2014, 35:1167–1174 Keywords: occult lesion localization, parathyroid adenoma, radioguided surgery Departments of a Nuclear Medicine, b Endocrine Surgery, c Pathology and d Endocrinology, Güven Hospital, Ankara, Turkey Correspondence to Seyfettin Ilgan, MD, Department of Nuclear Medicine, Güven Hospital, 06540 Kavaklıdere, Ankara, Turkey Tel: + 90 312 457 2486; fax: + 90 312 457 2525; e-mail: ilgan@hotmail.com Received 13 June 2014 Revised 26 July 2014 Accepted 29 July 2014 Introduction Primary hyperparathyroidism (PHPT) is the most com- mon cause of benign hypercalcemia resulting mainly (80–85% or more) from sporadic, single parathyroid ade- nomas, followed by hyperplasia, double adenomas, and parathyroid carcinoma [1]. Surgery continues to remain the mainstay of treatment for PHPT. Although there is still an important role for formal bilateral neck explora- tion, a unilateral focused surgical approach has gained wide acceptance in cases of solitary parathyroid adeno- mas, which is the most commonly seen type of tumor [2,3]. Several authors have shown that minimally invasive parathyroidectomy (MIP) results in reduced operative time, lower hospital costs, shorter length of stay, and fewer events of transient hypocalcemia with cure rates equal to that of bilateral neck exploration (95%) [4,5]. Obviously the success of MIP is strongly dependent on accurate preoperative imaging techniques that can pre- dict the presence of single gland disease. High-resolution ultrasonography (US) and dual-phase scintigraphy with technetium-99m methoxyisobutylisonitrile ( 99m Tc)-MIBI are the currently favored localization studies, with high sensitivity (>85%) in identifying hyperfunctioning parathyroid glands. In particular, the concordant results of both studies correctly identify single adenomas in 95% of cases [6]. Confirmation of the parathyroid origin of a suspicious lesion could be made by measuring the parathyroid hor- mone (PTH) in the needle aspirate of the suspicious lesions when scintigraphy and US are inconclusive or discordant. It has been reported that PTH assay in nee- dle aspirates is a simple and highly specific method and shows superior performance in comparison with para- thyroid scintigraphy or US alone [7,8]. Other imaging or localization studies, including com- puted tomography, MRI, PET, and selective venous sampling, are mainly recommended for patients with negative scintigraphy and US studies and for those with persistent or recurrent PHPT [9]. Original article 0143-3636 © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI: 10.1097/MNM.0000000000000188 Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.