SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules : What is the role of functional imaging and isotopic treatment?

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the role of thyroid scintigraphy in the diagnosis of autonomous thyroid nodules, nuclear medicine in nodules with indeterminate cytology and iodine treatment for autonomous thyroid nodules.

Quantitative dual isotope 123iodine/99mTc-MIBI scintigraphy: A new approach to rule out malignancy in thyroid nodules.

BACKGROUND: The aim of this study was to evaluate the role of dual isotope 123Iodine/99mTc-MIBI thyroid scintigraphy (IMS) in discriminating between malignant and benign lesions in indeterminate nodules using quantitative analysis methods. METHODS: Thirty-five consecutive patients with thyroid nodules of indeterminate or non-diagnostic cytology and cold on 123Iodine scintigraphy (10 Bethesda I, 24 Bethesda III-IV, 1 in which cytology was impossible) underwent IMS between 2017 and 2019 with uptake quantification at two time points ahead of thyroidectomy: early and late. Images were analyzed by two blinded physicians. RESULTS: Twelve nodules were malignant and 23 benign on histopathology. Mean uptake values were lower in benign than in malignant nodules at both time points: early, 8.7±4.1 versus 12.9±3.5 (P=0.005); and late, 5.3±2.7 versus 7.7±1.1 (P=0.008). Interobserver reproducibility was excellent. The intraclass correlation coefficient was 0.86 in benign and 0.92 in malignant lesions for early uptake result (ER) and 0.94 and 0.85 respectively for late uptake result (LR). The optimal LR cut-off  to exclude a diagnosis of malignancy was set at 5.9 . The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of this cut-off were, respectively, 100%, 65.2%, 60%, 100% and 77.1%. CONCLUSION: Despite some study limitations, quantitative analysis of 99mTc-MIBI thyroid scintigraphy had a good reproducibility, which could help to rule out malignancy in non-diagnostic or indeterminate thyroid nodules and thereby reducing the number of patients undergoing unnecessary surgery when LR is below 5.9.

Hyperparathyroidism in pregnancy and 99mTc-MIBI scintigraphy.

INTRODUCTION: Primary hyperparathyroidism (PHPT) during pregnancy can be responsible for serious maternal and foetal complications and should be treated by elective low-risk, minimally invasive surgery. Preoperative assessment of hyperfunctioning parathyroid glands is classically based on high-resolution neck ultrasound (US) and 99mTc-sestamibi/123I scintigraphy. However, administration of any radiopharmaceutical during pregnancy must be limited and justified and US alone may be sufficient to localize an abnormal parathyroid gland. CASE REPORT: We report the case of a 4-month pregnant woman with severe primary hyperparathyroidism, in whom US failed to localize the abnormal parathyroid gland. 99mTc-sestamibi scintigraphy was performed in preference to 18-fluorocholine (FCH)-PET/CT on the basis of a multidisciplinary decision. As 99mTc-MIBI demonstrated an hyperfunctioning right inferior parathyroid, 123I was not administered. A large right paravertebral parathyroid adenoma was successfully removed, as confirmed by decreased postoperative serum parathyroid hormone and calcium levels. The eutrophic newborn infant was delivered at term, with normal serum calcium and TSH levels. DISCUSSION: In pregnant women with primary hyperparathyroidism, US alone may be sufficient when it localizes the abnormal parathyroid gland, allowing elective low-risk minimally invasive surgery. Otherwise, a multidisciplinary approach is mandatory to select the radiopharmaceutical that can be safely used to identify the hyperfunctioning parathyroid gland with minimal risks for the foetus.

Tissue-muscle perfusion assessed by one day 99mTc-MIBI rest-dipyridamol scintigraphy in non-diabetic and diabetic patients. / Perfusión tejido-músculo evaluada mediante protocolo de un día de gammagrafía reposo-dipiramidol con 99mTc-MIBI en pacientes no diabéticos y diabéticos.

AIM: To determine the perfusion reserve of the lower limbs using the method 99mTc-MIBI (rest-dipyridamole) perfusion scintigraphy (one-day protocol) in the diagnostic evaluation of peripheral artery disease (PAD) in patients with and without diabetes mellitus (DM). MATERIAL AND METHODS: We performed tissue-muscle perfusion scintigraphy (TMPS) of the lower limbs, through one-day rest-dipyridamole protocol with 99mTc-MIBI in 24 patients, divided in two groups according to the presence of diabetes - patients with DM (Dp) 13/24 (54%), 2 males and 9 female patients, age 63±13 years and patients without DM (NDp) 11/24 (46%), 3 males and 10 females, age 61±14 years. RESULTS: In the dynamic phase of the rest study, the time of maximum activity (Tmax), in the early arterial phase, of the calf region was significantly prolonged in Dp compared to NDp, with lower accumulation of the radiotracer in the 1st minute (85%/87% in Dp vs. 89%/90% in NDp, ns). 4/11 of NDp (36.4%) and 7/13 of Dp (53.8%) registered pathological value of the inter-extremity index of the calves in the stress study. Perfusion reserve (PR) of the thighs (LT, RT) and calves (LC, RC) calculated with the formula "(ROI stress-ROI rest)×100%/ROI rest", was significantly lower in Dp: LT: 28±19% vs. 43±24% in NDp, p<0.05; RT: 27±17% vs. 40±25% in NDp, p<0.05; LC: 22±15% vs. 36±15% in NDp, p<0.01; RC: 25±15% vs. 38±14% in NDp, p<0.01. CONCLUSION: This one-day protocol (rest-dipyridamole with 99mTc-MIBI) of perfusion scintigraphy of lower limbs is considered as a useful procedure in PAD assessment, especially the asymptomatic form. TMPS of the lower limbs in our study indicated that perfusion reserve in patients with DM was significantly lower, compared to the patients without diabetes.

Cystic parathyroid adenoma: Primary hyperparathyroidism without 99mTc-MIBI uptake. / Adenoma quístico paratiroideo: hiperparatiroidismo primario sin captación de 99mTc-MIBI.

Cystic parathyroid adenoma is a rare disease (<0.01% of all cervical masses) that associates primary hyperparathyroidism in 9% of cases. Parathyroid scintigraphy is essential for its diagnosis with uncommon false negative results. Hybrid SPECT/CT equipments allow a more accurate diagnosis. Functional cystic parathyroid adenomas are surgically treated. A case of a 64-year-old woman with diagnoses of hyperparathyroidism and a cystic parathyroid adenoma without uptake in scintigraphy is described.

Radioguided thyroidectomy for follicular tumors: Multicentric experience.

BACKGROUND: The diagnosis of thyroid nodular diseases requires an integrated approach that has been widely established over the past years. This strategy includes: ultrasonography (US) with; implemented Color-Power-Doppler, conventional scintigraphy also with positive indicators, specific pathological studies targeted by immunohistochemically-assays, and the fine needle; aspiration biopsy (FNAB), which, usually, in case of "Follicular Lesions" (10-20%) findings is; unable to distinguish carcinoma from follicular adenoma, then indicating the necessity of surgery to; obtain a correct diagnosis. The aim of this study was to evaluate the role of the scintigraphy with; positive indicators, both preoperatively in diagnostic approach of the thyroid nodules and; intraoperatively as a guide to the extension of the surgical excision. METHODS: On 4482 Thyroidectomy performed, we selected 360 cases of follicular neoplasms (192; females and 168 males). In the preoperative phase, these patients underwent 99 m Tc-sestaMIBI; scintigraphy with both early (10 min) and late (2 h) image acquisition, which were later; compared to the ones obtained by image subtraction of means 99 m Tc-pertechnetate. Following the; sestamibi administration before intervention, we selected the most up-taking nodularity with the; assistance of a specific surgical probe (Neoprobe), quantifying uptake with relation to the surgical pathology, for an amount of 324 total thyroidectomies and 36 hemi thyroidectomies. RESULTS: In all cases of multinodular goiter the benign nodules showed an intraoperative low sestamibi uptake whereas follicular carcinomas showed both a high preoperative uptake and, as a; percentage, the highest values of intraoperative uptake; on the other hand, follicular adenomas had; both pre-and intraoperative mean values of uptake. On the contrary, papillary carcinomas only; showed a mild uptake. CONCLUSIONS: Preoperative sestamibi scintigraphy confirmed its importance in improving the information obtained through different diagnostic investigations. Also intraoperatively, it pointed; out high-risk nodules more accurately. Therefore, radio (Sestamibi) guided surgery could have an; interesting rule in the thyroid follicular lesion treatment.