18F‐Fluorocholine PET/CT and Parathyroid 4D Computed Tomography for Primary Hyperparathyroidism: The Challenge of Reoperative Patients

Abstract

Background To evaluate FCH‐PET/CT and parathyroid 4D‐CT so as to guide surgery in patients with primary hyperparathyroidism (pHPT) and prior neck surgery. Methods Medical records of all patients referred for a FCH‐PET/CT in our institution were systematically reviewed. Only patients with pHPT, a history of neck surgery (for pHPT or another reason) and an indication of reoperation were included. All patients had parathyroid ultrasound (US) and Tc‐99m‐sestaMIBI scintigraphy, and furthermore, some patients had 4D‐CT. Gold standard was defined by pathological findings and/or US‐guided fine‐needle aspiration with PTH level measurement in the washing liquid. Results Twenty‐nine patients were included in this retrospective study. FCH‐PET/CT identified 34 abnormal foci including 19 ectopic localizations. 4D‐CT, performed in 20 patients, detected 11 abnormal glands at first reading and 6 more under FCH‐PET/CT guidance. US and Tc‐99m‐sestaMIBI found concordant foci in 8/29 patients. Gold standard was obtained for 32 abnormal FCH‐PET/CT foci in 27 patients. On a per‐lesion analysis, sensitivity, specificity, positive and negative predictive values were, respectively, 96%, 13%, 77% and 50% for FCH‐PET/CT, 75%, 40%, 80% and 33% for 4D‐CT. On a per‐patient analysis, sensitivity was 85% for FCH‐PET/CT and 63% for 4D‐CT. FCH‐PET/CT results made it possible to successfully remove an abnormal gland in 21 patients, including 12 with a negative or discordant US/Tc‐99m‐sestaMIBI scintigraphy result, with a global cure rate of 73%. Conclusion FCH‐PET/CT is a promising tool in the challenging population of reoperative patients with pHPT. Parathyroid 4D‐CT appears as a confirmatory imaging modality.

Localization of Parathyroid Disease in Reoperative Patients with Primary Hyperparathyroidism

“…Analogously, 18 F-FCH PET/CT has higher spatial resolution, lower radiation burden (2.8 mSv), and shorter total study time (38 minutes) than SPECT/CT (11.8 mSv, total study time 120 minutes) [90][91][92]. In a study of 29 patients undergoing reoperation for PHPT, 18 F-FCH PET/CT was more sensitive than ultrasound, sestamibi scintigraphy, and 4DCT for localizing parathyroid disease; however, it is likely that patients who proceed to PET/ CT have negative or discordant results from more commonly utilized modalities in the first place [22]. Moreover, 18 F-FCH PET/CT often fails to detect hyperplastic glands and ectopic adenomas, both of which constitute common causes of reoperation [87,[93][94][95].…”

“…While some studies report that multigland disease accounts for more than half of all reoperative cases [3,11], most studies attribute the majority of reoperative cases (as high as 79%) to the failed detection of a single adenoma [1,13,[15][16][17][18][19]. Although ectopic adenomas may be up to four times as common in the reoperative setting than in the primary setting [11,18,20,21], the majority of missed single adenomas are orthotopic [4,14,19,22,23]. Multiple endocrine neoplasia type 1 (MEN1) specifically accounts for between 8.5 and 10.3% of all reoperative cases, causing both pPHPT and rPHPT [11,15].…”

“…Today, however, surgical cure rates in the reoperative setting are reported between 86 and 100%, with a meta-analysis by Singh Ospina and colleagues reporting a cure rate of 98% with bilateral neck exploration and 97% with minimally invasive parathyroidectomy [4,12,13,[37][38][39][40][41]. Common complications after reoperation include injury to the recurrent laryngeal nerve and permanent hypoparathyroidism, the reported frequencies of which vary widely from 0 to 15% for each [4,12,22,[40][41][42]. Given the challenges that accompany reoperative parathyroidectomy, it is crucial to seek the expertise of high-volume and experienced parathyroid surgeons when assessing a patient with pPHPT or rPHPT [7,34].…”

“…11 C-MET PET/CT has a sensitivity of 61% in reoperative patients, though this figure may be as low as 40% in challenging subgroups such as those with negative sestamibi scintigraphy ( Figure 5) [40,86]. However, 18 Ffluoromethylcholine ( 18 F-FCH) PET/CT demonstrates strong potential for localizing persistent or recurrent disease with sensitivities between 96 and 100% (albeit in studies with small sample sizes) [22,87]. In patients with multigland disease, 18 F-FCH PET/CT has a reported sensitivity of 79% and PPV of 100% [87].…”

Lokalisationsdiagnostik von Nebenschilddrüsenadenomen mittels PET/CT

“…werden mehrphasige Protokolle verwendet um die Lokalisation des Nebenschilddrüsenadenoms zu erreichen. So konnte für ein mehrphasiges 4D-CT ein positiver prädiktiver Wert von 80 % [13] gezeigt werden. Durch die wiederholten Computertomografiephasen derselben anatomischen Region resultiert jedoch eine nicht unerhebliche Strahlenexposition (bis 27 mSv).…”