IOPTH monitoring has substantially changed the surgical management of primary hyperparathyroidism by providing objective, real-time evidence of adequate resection [3–6]. The rapid clearance of circulating PTH means that a sustained decrease after gland excision distinguishes cure of true single-gland disease from persistent multigland disease, without depending solely on visual assessment of the glands or frozen section [7]. In this patient, technetium-99m sestamibi scintigraphy could not be performed because his weight exceeded the certified load limit of the gamma-camera table. This examination is one of the two standard first-line localization studies and has a reported sensitivity of approximately 79% when used alone [17]. The table weight limit is a practical constraint of nuclear medicine imaging that disproportionately affects patients with morbid obesity. Localization instead depended on ultrasonography, which has a reported sensitivity of approximately 76% alone [17], and corroborating contrast-enhanced CT. Both studies identified a left inferior parathyroid adenoma. Concordant localization and the 90% intraoperative PTH decrease at 10 minutes provided strong support for the adequacy and safety of a focused procedure. The case illustrates that minimally invasive parathyroidectomy does not invariably require a diagnostic sestamibi scan when concordant anatomical imaging and IOPTH monitoring are available.

Morbid obesity creates a specific and under-recognized obstacle to conventional nuclear medicine localization. Most gamma-camera and SPECT/CT tables have manufacturer-specified weight limits, commonly 150–200 kg. Above these limits, the examination cannot be performed safely, irrespective of its clinical indication. High-resolution ultrasound and cross-sectional imaging, either CT or four-dimensional CT where available, then become the principal and sometimes the only feasible methods of preoperative localization. Surgeons and radiologists serving populations with a high prevalence of obesity should identify this constraint early in the diagnostic pathway, rather than discovering it after an unsuccessful attempt at scintigraphy.

Focused minimally invasive parathyroidectomy (MIP) guided by IOPTH achieves cure rates statistically comparable to those of conventional bilateral neck exploration, with shorter operating times, less extensive dissection, and reduced risk to nerves and parathyroid glands outside the surgical target [14–16]. A 2020 Cochrane systematic review reported operative success within six months in approximately 97% of patients undergoing MIP and 99% undergoing bilateral exploration. When adequate localization and IOPTH monitoring were used, the difference between approaches was not statistically significant [15]. Current international guidelines, including those of the American Association of Endocrine Surgeons and the Fifth International Workshop on Primary Hyperparathyroidism, support either approach for appropriately selected patients with well-localized disease and recommend adjunctive IOPTH monitoring when a focused procedure is planned [11,13].

The Miami criterion remains the most extensively validated of the proposed intraoperative biochemical criteria and was used in this case [7,8]. It requires a PTH decrease of more than 50% from the highest pre-incision or pre-excision value within 10 minutes of excision. Comparisons of the Miami, Halle, Rome, and Vienna criteria have demonstrated a favorable balance of sensitivity and specificity for the Miami criterion. Nevertheless, double adenomas or asymmetric multigland disease may occasionally produce falsely reassuring results. Biochemical findings must therefore be considered alongside preoperative imaging and intraoperative gland inspection, rather than interpreted as an isolated measurement [10].

Reports from our region have historically described later presentation of primary hyperparathyroidism and a greater burden of skeletal and renal complications than in cohorts routinely screened for asymptomatic hypercalcemia [19,20]. The nephrolithiasis and osteoporosis in this patient were consistent with that pattern. Our institution already has an experienced parathyroid surgery practice [18]. Incorporating Miami-criterion-guided IOPTH monitoring into this practice provides a structured, evidence-based means of offering focused, minimally invasive surgery to patients who might otherwise undergo routine bilateral exploration.

The observations are subject to the inherent limitations of a single case, and longer follow-up is needed to establish durable biochemical cure. We nevertheless consider this first successful institutional experience useful as a local benchmark and as an example for emerging endocrine surgery programs in comparable settings of how IOPTH monitoring can be safely incorporated into standard preoperative localization pathways.