The Definition of Recurrence of Differentiated Thyroid Cancer: A Systematic Review of the Literature.

Background Recurrence is a key outcome to evaluate treatment effect of differentiated thyroid carcinoma (DTC). However, no consistent definition of recurrence is available in current literature or international guidelines. Therefore, the primary aim of this systematic review was to delineate the definitions of recurrence of DTC, categorized by total thyroidectomy with radioactive iodine ablation (RAI), total thyroidectomy without RAI and lobectomy, to assess if there is a generally accepted definition among these categories. Methods This study adhered to 2020 PRISMA statement. In December 2023, systematic literature search in MEDLINE and EMBASE was performed for studies reporting on recurrence of DTC, from January 2018 to December 2023. Studies that did not provide a definition were excluded. Primary outcome was the definition of recurrence of DTC. Secondary outcome whether studies differentiated between recurrence and persistent disease. Two independent investigators screened titles and abstracts, followed by full-text assessment and data extraction. The study protocol was registered in PROSPERO,CRD42021291753. Results In total, 1450 studies were identified. Seventy studies met inclusion criteria, including 69 retrospective studies and one RCT. Median number of patients in included studies was 438 (range 25 - 2297). Seventeen studies (24.3%) reported on lobectomy, four studies (5.7%) on total thyroidectomy without RAI, and 49 studies (70.0%) with RAI. All studies defined recurrence using one or a combination of four diagnostic modalities: cytology/pathology, imaging studies, thyroglobulin(-antibodies), predetermined minimum tumor-free time span. The most common definition of recurrence following lobectomy was cytology/pathology-proven recurrence (47.1% of this subgroup), following total thyroidectomy with RAI was cytology/pathology-proven recurrence and/or anomalies detected on imaging studies (22.4% of this subgroup). No consistent definition was found following total thyroidectomy without RAI. Nine studies (12.9%) differentiated between recurrence and persistent disease. Conclusion Our main finding is that there is no universally accepted definition for recurrence of DTC in the current studies across any of the treatment categories. The findings of this study will provide the basis for a future, international Delphi-based proposal to establish a universally accepted definition of recurrence of DTC. A uniform definition could facilitate global discussion and enhance the assessment of treatment outcomes regarding recurrence of DTC.

Robotic and Laparoscopic Adrenalectomy for Pheochromocytoma: An International Multicenter Study.

BACKGROUND AND OBJECTIVE: Robotic adrenalectomy (RA) has attracted interest as an alternative to laparoscopic adrenalectomy (LA) for patients with pheochromocytoma, although its beneficial effects are uncertain. Our aim was to compare RA and LA outcomes for these patients. METHODS: Data for patients who underwent RA or LA for pheochromocytoma in 46 international centers between 2012 and 2022 were reviewed. We analyzed baseline characteristics and postoperative complications at discharge, 90 d, and 1 yr. We conducted propensity score matching (PSM; 1:1 ratio) and multivariable analyses to evaluate outcomes and risk factors for the occurrence of complications and higher Comprehensive Complication Index (CCI). KEY FINDINGS AND LIMITATIONS: Of 1755 patients, 1613 (91.9%) underwent LA and 142 (8.1%) underwent RA. Estimated blood loss, conversion rate, complication rate, and CCI at discharge, 90 d, and 1 yr were similar between the groups. However, RA was associated with a longer operative time in comparison to LA (100 vs 123 min; p < 0.001), but not after PSM (p = 0.120). Multivariable analysis revealed that Charlson comorbidity index (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.07-1.29; p = 0.001), and tumor size per 1-cm increment (OR 1.13, 95% CI 1.07-1.21; p < 0.001) were independently associated with the incidence of complications, but there was no significant difference in complication rates between the LA and RA groups (OR 1.09, 95% CI 0.63-1.87; p = 0.767). After PSM, RA was associated with a lower rate of severe (grade ≥3a) complications in comparison to LA (p = 0.023). CONCLUSIONS AND CLINICAL IMPLICATIONS: RA is a safe alternative to LA and yields similar outcomes for patients with pheochromocytoma. RA may be associated with a lower likelihood of severe complications. Further studies are warranted to determine the role of robotic surgery in pheochromocytoma. PATIENT SUMMARY: Pheochromocytoma is a rare tumor in the adrenal gland and the gold-standard treatment is surgical removal. We assessed patient outcomes after robot-assisted surgery compared with laparoscopic surgery and found that outcomes are similar, but the rate of severe complications may be lower if a surgical robot is used.

PRAP study-partial versus radical adrenalectomy in hereditary pheochromocytomas.

OBJECTIVE: Hereditary pheochromocytoma (hPCC) commonly develops bilaterally, causing adrenal insufficiency when standard treatment, radical adrenalectomy (RA), is performed. Partial adrenalectomy (PA) aims to preserve adrenal function, but with higher recurrence rates. This study compares outcomes of PA versus RA in hPCC. METHODS: Patients with hPCC due to pathogenic variants in RET, VHL, NF1, MAX, and TMEM127 from 12 European centers (1974-2023) were studied retrospectively. Stratified analysis based on surgery type and initial presentation was conducted. The main outcomes included recurrence, adrenal insufficiency, metastasis, and mortality. RESULTS: The study included 256 patients (223 RA, 33 PA). Ipsilateral recurrence rates were 9/223 (4%) after RA versus 5/33 (15%) after PA (P = 0.02). Metastasis and mortality did not differ between groups. Overall, 103 patients (40%) underwent bilateral adrenalectomy either synchronously or metachronously (75 RA, 28 PA). Of these, 46% developed adrenal insufficiency after PA.In total, 191 patients presented with initial unilateral disease, of whom 50 (26%) developed metachronous contralateral disease, most commonly in RET, VHL, and MAX. In patients with metachronous bilateral disease, adrenal insufficiency developed in 3/4 (75%) when PA was performed as the first operation followed by RA, compared to 1/7 (14%) when PA was performed as the second operation after prior RA (P = 0.09). CONCLUSION: In patients with hPCC undergoing PA, local recurrence rates are higher than after RA, but metastasis and disease-specific mortality are similar. Therefore, PA seems a safe method to preserve adrenal function in patients with hPCC, in cases of both synchronous and metachronous bilateral disease, when performed as a second operation.

Endoscopic versus surgical resection of duodenal neuroendocrine neoplasms between 10 and 20 mm: A multi-centered retrospective cohort study.

INTRODUCTION: Recommendations for resection technique of duodenal neuroendocrine neoplasms (D-NEN) with a size between 10 and 20 mm are lacking. The primary aim was to compare overall survival (OS) and progression-free survival (PFS) after endoscopic resection (ER) with surgical resection (SR). The secondary aim was to assess the incidence and clinical variables correlated with OS. METHODS: Data of patients with D-NENs between 2008 and 2018 were extracted from the Netherlands Cancer Registry and the Dutch Nationwide Pathology Databank. RESULTS: A total of 259 patients were identified, of which 138 were included: 98 (68 %) underwent ER and 44 patients (32 %) underwent SR. Of these, 38 patients had D-NENs sized between 10 and 20 mm. ER Patients were more frequently male and had a lower T-stage and tumour size than SR patients (all P < 0.05). Positive resection margins were observed more frequently after ER compared to SR (71 % vs 15 %, P < 0.005). No patients with tumours between 10 and 20 mm died after ER or SR (median follow-up 71.8 vs. 52.0 months). PFS rates were not significantly different after ER compared to SR (P = 0.672). Recurrence rates were 13 % for ER and 7 % for SR (P = 0.604). CONCLUSION: Between 2008 and 2018, the incidence increased from 0.06 to 0.11 per 100,000 patients per year. OS after ER or SR did not differ for D-NEN between 10 and 20 mm. Recurrence and PFS rates were not significantly different. These results suggest that D-NENs sized between 10 and 20 mm could potentially be treated first with ER. Future studies are needed to confirm this hypothesis.

Omitting the Escalating Dosage of Alpha-adrenergic Blockade before Pheochromocytoma Resection: Implementation of a Treatment Strategy in Discordance with Current Guidelines.

OBJECTIVE: This study describes the effects of introducing a protocol omitting preoperative α-blockade dose-escalation (de-escalation) in a prospective patient group. SUMMARY BACKGROUND DATA: The decline of mortality and morbidity associated with pheochromocytoma resection is frequently attributed to the introduction of preoperative α-blockade. Current protocols require preoperative α-blockade dose-escalation and multiple-day hospital admissions. However, correlating evidence is lacking. Moreover, recent data suggest equal perioperative safety regardless of preoperative α-blockade escalation. METHODS: Single-institution evaluation of protocol implementation, including patients who underwent adrenalectomy for pheochromocytoma between 2015 and 2023. Intraoperative hemodynamic control was regulated by active adjustment of blood pressure using vasoactive agents. The primary outcome was intraoperative hypertension, defined as time-weighted average of systolic blood pressure (TWA-SBP) above 200 mm Hg. Secondary outcomes included perioperative hypotension, postoperative blood pressure support requirement, hospital stay duration and complications. RESULTS: Of 102 pheochromocytoma patients, 82 were included; 44 in the de-escalated preoperative α-adrenergic protocol and 38 following the previous dose-escalation protocol. Median [IQR] TWA-SBP above 200 mm Hg was 0.01 [0.0-0.4] mm Hg in the de-escalated group versus 0.0 [0.0-0.1] mm Hg in the dose-escalated group (P=0.073). Median duration of postoperative continuous norepinephrine administration was 0.3 hrs [0.0-5.5] versus 5.1 hrs [0.0-14.3], respectively (P=0.003). Postoperative symptomatic hypotension occurred in 34.2% versus 9.1% of patients (P=0.005). Median hospital stay was 2.5 days [1.9-3.6] versus 7.1 days [6.0-11.9] (P<0.001). No significant differences in complication rates were observed. CONCLUSION: Our data suggest that adrenalectomy for pheochromocytoma employing a de-escalated preoperative α-blockade protocol is safe and results in a shorter hospital stay.

Long-term oncological outcomes of follicular thyroid cancer in adolescents and young adults: A nationwide population-based study.

BACKGROUND: Follicular thyroid carcinoma (FTC) in adolescents and young adults (AYAs) is rare and data on long-term oncological outcomes are scarce. This study aimed to describe the long-term recurrence and survival rates of AYAs with FTC, and identify risk factors for recurrence. METHODS: This is a retrospective cohort study combining two national databases, including all patients aged 15-39 years, diagnosed with FTC in The Netherlands between 2000 and 2016. Age, sex, tumor size, focality, positive margins, angioinvasion, pT-stage, and pN-stage were included in a Cox proportional hazard model to identify risk factors for recurrence. RESULTS: We included 192 patients. Median age was 31.0 years (IQR 24.7-36.3) and the male to female ratio was 1:4.1. Most patients presented with a minimally invasive FTC (MI-FTC) (95%). Five patients presented with synchronous metastases (2.6%), including two with locoregional metastases (1%) and three with distant metastases (1.6%). During a median follow-up of 12.0 years, three patients developed a recurrence (1.6%), of which one patient developed a local recurrence (33%), and two patients a distant recurrence (67%). Five patients died during follow-up (2.6%). Cause of death was not captured. A Cox proportional hazard model could not be performed due to the low number of recurrences. CONCLUSIONS: FTC in AYAs is generally characterized as a low-risk tumor, as it exhibits a very low recurrence rate, a high overall survival, and it typically presents as MI-FTC without synchronous metastases. These findings underscore the favorable long-term oncological prognosis of FTC in AYAs.

Impact of EDP-M on survival of patients with metastatic adrenocortical carcinoma: A population-based study.

INTRODUCTION: Historically, stage IV adrenocortical carcinoma (mACC) has a poor prognosis with a median overall survival (OS) of only 5 months. Based on the FIRM-ACT trial published in 2012, guidelines now advise first line systemic treatment with etoposide, cisplatin, doxorubicin and mitotane (EDP-M). The effect of EDP-M on patient survival in clinical practice in the Netherlands is unknown. METHODS: The data of all patients with mACC (2005-2020) were obtained from the Netherlands comprehensive cancer organization (IKNL). The effect of EDP-M on patient survival was assessed using Kaplan-Meier analysis and multivariate Cox regression analysis including clinical, therapy and tumor characteristics. RESULTS: In total 167 patients with mACC were included. For patients diagnosed from 2014 onwards, EDP-M (in 22 patients (22%)) lead to a numerically but not statistically significant improved OS compared to those not receiving EDP-M (11.8 vs 5.6 months, p = 0.525). For systemic treatments, patients treated with mitotane only had the best 5-year OS (11.4%, p = 0.006) regardless of year of diagnosis. In multivariate Cox regression analysis EPD-M was not associated with OS; palliative adrenalectomy (HR: 0.26, p = <.001) and local treatment of metastases (HR: 0.35, p = 0.001) were associated with a better OS and a primary tumor Ki-67 index > 20% (HR: 2.67, p = 0.003) with a worse OS from 2014 onwards. Patients diagnosed before 2014 had a significantly poorer OS compared to from 2014 onwards (5-yr: 4.5 vs 8.4%, OS: 6.8 vs 8.3 months, p = 0.032). CONCLUSION: OS for mACC in the Netherlands has improved in the last decade. Receiving EDP-M did not significantly improve OS for patients with mACC. The use of multimodality treatment including palliative adrenalectomy, mitotane and local treatment of (oligo-)metastases in appropriately selected patients has improved the OS for mACC patients since 2014.

Thyroid Incidentalomas: Incidence and Oncological Implication in Patients with Esophageal Cancer.

INTRODUCTION: Thyroid incidentalomas are often encountered during imaging performed for the workup of esophageal cancer. Their oncological significance is unknown. This study aimed to establish incidence and etiology of thyroid incidentalomas found during the diagnostic workup of esophageal cancer. METHODS: All esophageal cancer patients referred to or diagnosed at the Amsterdam UMC between January 2012 and December 2016 were included. Radiology and multidisciplinary team meeting reports were reviewed for presence of thyroid incidentalomas. When present, the fluorodeoxyglucose-positron emission tomography/computed tomography (18FDG-PET/CT) or CT was reassessed by a radiologist. Primary outcome was the incidence and etiology of thyroid incidentalomas. RESULTS: In total, 1,110 esophageal cancer patients were included. Median age was 66 years, most were male (77.2%) and had an adenocarcinoma (69.4%). For 115 patients (10.4%), a thyroid incidentaloma was reported. Two thyroidal lesions proved malignant. One was an esophageal cancer metastasis (0.9%) and one was a primary thyroid carcinoma (0.9%). Only the primary thyroid carcinoma resulted in treatment alteration. The other malignant thyroid incidentaloma was in the context of disseminated esophageal disease and ineligible for curative treatment. CONCLUSION: In this study, thyroid incidentalomas were only very rarely oncologically significant. Further etiological examination should only be considered in accordance with the TI-RADS classification system and when clinical consequences are to be expected.

A 15-year-old Girl with a Lateral Neck Mass Turning Out to Be Papillary Thyroid Carcinoma-Lateral Ectopic Papillary Thyroid Carcinoma or Lymph Node Metastasis?

Lateral neck lesions in children are common and involve various infectious or inflammatory etiologies as well as embryological remnants such as branchial cleft cysts. Although unusual, ectopic thyroid tissue can also present as a lateral neck mass. Here, we present an unusual case of a 15-year-old girl treated for an asymptomatic lateral neck mass that after surgical removal was found to be papillary thyroid carcinoma (PTC). However, after removal of the thyroid gland, no primary thyroid tumor was found. The question arose whether the lateral neck lesion was a lymph node metastasis without identifiable primary tumor (at histological evaluation) or rather malignant degeneration of ectopic thyroid tissue. Total thyroidectomy was performed with postoperative adjuvant radioactive iodine ablation. Even though PTC in a lateral neck mass without a primary thyroid tumor has been described previously, pediatric cases have not been reported. In this report we share our experience on diagnosis, treatment and follow-up, and review the existing literature.

Bilaterality, not multifocality, is an independent risk factor for recurrence in low-risk papillary thyroid cancer.

BACKGROUND: The impact of multifocality and bilaterality on recurrence in patients with low-risk papillary thyroid cancer (PTC) is relevant when considering patients for a de-escalated treatment strategy: hemithyroidectomy instead of total thyroidectomy followed with or without radioactive iodine. This study aims to analyze contralateral tumor probability in patients treated for low-risk PTC and assess multifocality and bilaterality as possible predictors for recurrence. METHODS: Patients with low-risk PTC treated with total thyroidectomy followed with or without radioactive iodine in the Netherlands between 2005 and 2015 were included in this study. Patients were identified from the Netherlands Comprehensive Cancer Organization (IKNL) and linked with the nationwide network and registry of Pathology in the Netherlands (PALGA). Contralateral tumor probability and recurrence were assessed. RESULTS: Of 791 included patients, 41.8% (331 of 791) had multifocal disease, with 68.9% (228 of 331) of those patients having bilateral disease. The contralateral tumor probability after hemithyroidectomy was 24.6% (150 of 610) for patients with unifocal disease and 43.1% (78 of 181) for patients with multifocal disease. We found a higher trend of recurrence in patients with bilateral disease, regardless of multifocality: in patients with contralateral disease after precompletion diagnosed unifocal disease 7.3% (11 of 150) had recurrent disease, and patients without contralateral disease after precompletion diagnosed multifocal disease 1.9% (2 per 103) had recurrence. Cox regression analysis showed that bilaterality (hazard ratio = 3.621, 95% confidence interval = 1.548 to 8.471) was the sole statistically significant risk factor for recurrence. CONCLUSION: Low recurrence rates are found in patients with either multifocal or bilateral disease with low-risk PTC. Bilaterality should be taken into account when considering these patients for de-escalated treatment strategy.

Clinical Prediction Models for Recurrence in Patients with Resectable Grade 1 and 2 Sporadic Non-Functional Pancreatic Neuroendocrine Tumors: A Systematic Review.

Recurrence after resection in patients with non-functional pancreatic neuroendocrine tumors (NF-pNET) has a considerable impact on overall survival. Accurate risk stratification will tailor optimal follow-up strategies. This systematic review assessed available prediction models, including their quality. This systematic review followed PRISMA and CHARMS guidelines. PubMed, Embase, and the Cochrane Library were searched up to December 2022 for studies that developed, updated, or validated prediction models for recurrence in resectable grade 1 or 2 NF-pNET. Studies were critically appraised. After screening 1883 studies, 14 studies with 3583 patients were included: 13 original prediction models and 1 prediction model validation. Four models were developed for preoperative and nine for postoperative use. Six models were presented as scoring systems, five as nomograms, and two as staging systems. The c statistic ranged from 0.67 to 0.94. The most frequently included predictors were tumor grade, tumor size, and lymph node positivity. Critical appraisal deemed all development studies as having a high risk of bias and the validation study as having a low risk of bias. This systematic review identified 13 prediction models for recurrence in resectable NF-pNET with external validations for 3 of them. External validation of prediction models improves their reliability and stimulates use in daily practice.

Deescalating Follow-up After Hemithyroidectomy for Patients With Low-risk Papillary Thyroid Microcarcinoma.

Importance: Structural recurrent disease (RD) after surgical treatment of papillary thyroid microcarcinoma (mPTC) is rare. We hypothesized that the RD rate after hemithyroidectomy in low-risk patients with mPTC is low. Objective: To assess the occurrence of RD in Dutch patients with mPTC who received surgical treatment according to the Dutch guidelines. Design, Setting, and Participants: This nationwide retrospective cohort study included all patients who had undergone surgery with a diagnosis of cN0/cNx mPTC in the Netherlands between January 2000 and December 2020 were identified from the Netherlands Cancer Registry database. Patients with preoperative lymph node metastases were excluded. Two groups were defined: group 1 (incidental), mPTC in pathology report after thyroid surgery for another indication; and group 2 (nonincidental), patients with a preoperative highly suspect thyroid nodule (Bethesda 5) or proven mPTC (Bethesda 6). Dutch guidelines state that a hemithyroidectomy is sufficient in patients with unifocal, intrathyroidal mPTC. Main Outcomes and Measures: The occurrence of RD in patients with low-risk mPTC after hemithyroidectomy. Results: In total, 1636 patients with mPTC were included. Patients had a median (IQR) follow-up time of 71 (32-118) months. Median (IQR) age at time of diagnosis was 51 (41-61) years and 1292 (79.0%) were women. Overall, RD after initial treatment was seen in 25 patients (1.5%). The median (IQR) time to RD was 8.2 (3.6-16.5) months and 22 of the 25 (88%) patients developed RD within 2 years. Recurrent disease was not significantly different between both groups (group 1, n = 15 [1.3%]; group 2, n = 10 [2.1%]; difference, 0.8%; 95% CI, -0.5% to 2.5%). Of the 484 patients with nonincidental mPTC (group 2), 246 (50.8%) patients were treated with a hemithyroidectomy and follow-up in accordance with Dutch guidelines. Lymph node metastases were found in 1 of 246 (0.4%) patients after hemithyreoidectomy, and new mPTC in the contralateral thyroid was detected in 3 of 246 (1.2%) patients. Median (IQR) follow-up of this patient group was 37 (18-71) months. The 10-year probability of RD was 1.3% for patients without vascular invasion and 24.4% for patients with vascular invasion. Conclusions and Relevance: This nationwide cohort study found that overall, RD after hemithyroidectomy for patients with low-risk mPTC was rare (<2%). Based on these results, it seems reasonable to deescalate follow-up of patients with low-risk mPTC without vascular invasion after hemithyroidectomy. From a health care perspective, deescalation of follow-up may contribute to increased sustainability and accessibility to health care, both large challenges for the future.

Long-Term Oncological Outcomes of Papillary Thyroid Cancer and Follicular Thyroid Cancer in Children: A Nationwide Population-Based Study.

Introduction: Pediatric thyroid carcinoma is a rare malignancy and data on long-term oncological outcomes are sparse. The aim of this study was to describe the long-term oncological outcomes of pediatric papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC) in a national cohort, and to identify risk factors for recurrence. Methods: We conducted a nationwide, retrospective cohort study, in which we combined two national databases. Patients aged <18 years, diagnosed with PTC or FTC in the Netherlands between 2000 and 2016, were included. pT-stage, pN-stage, multifocality and angioinvasion were included in a Cox-regression analysis for the identification of risk factors for recurrence. Results: 133 patients were included: 110 with PTC and 23 with FTC. Patients with PTC most often presented with pT2 tumors (24%) and pN1b (45%). During a median follow-up of 11.3 years, 21 patients with PTC developed a recurrence (19%). Nineteen recurrences were regional (91%) and 2 were pulmonary (9%). No risk factors for recurrence could be determined. One patient who developed pulmonary recurrence died two years later. Cause of death was not captured. Patients with FTC most often presented with pT2 tumors (57%). One patient presented with pN1b (4%). In 70%, no lymph nodes were collected. None of the patients with FTC developed a recurrence or died. Conclusion: Pediatric PTC and FTC are two distinct diseases. Recurrence in pediatric PTC is common, but in FTC it is not. Survival for both pediatric PTC and FTC is very good.

Treatment patterns for adrenal metastases using surgery and SABR during a 10-year period.

We studied treatment patterns for adrenal metastases using surgery or SABR at a single institution during a 10-year period. The number of patients undergoing SABR doubled since 2016, without a change in numbers undergoing surgery. Both treatments resulted in low rates of acute toxicity and similar survivals.

International survey on opinions and use of minimally invasive surgery in small bowel neuroendocrine neoplasms.

INTRODUCTION: Although minimally invasive surgery is becoming the standard technique in gastrointestinal surgery, implementation for small bowel neuroendocrine neoplasms (SB-NEN) is lagging behind. The aim of this international survey was to gain insights into attitudes towards minimally invasive surgery for resection of SB-NEN and current practices. METHODS: An anonymous survey was sent to surgeons between February and May 2021 via (neuro)endocrine and colorectal societies worldwide. The survey consisted of questions regarding experience of the surgeon with minimally invasive SB-NEN resection and training. RESULTS: A total of 58 responses from five societies across 20 countries were included. Forty-one (71%) respondents worked at academic centers. Thirty-seven (64%) practiced colorectal surgery, 24 (41%) endocrine surgery and 45 (78%) had experience in advanced minimally invasive surgery. An open, laparoscopic or robotic approach was preferred by 23 (42%), 24 (44%), and 8 (15%) respondents, respectively. Reasons to opt for a minimally invasive approach were mainly related to peri-operative benefits, while an open approach was preferred for optimal mesenteric lymphadenectomy and tactile feedback. Additional training in minimally invasive SB-NEN resection was welcomed by 29 (52%) respondents. Forty-three (74%) respondents were interested in collaborating in future studies, with a cumulative median (IQR) annual case load of 172 (86-258). CONCLUSIONS: Among respondents, 69% applies minimally invasive surgery for resection of SB-NEN. Arguments for specific operative approaches differ, and insufficient training in advanced laparoscopic techniques seems to be a barrier. Future collaborative studies can provide better insight in selection criteria and optimal technique.

International Validation of a Nomogram to Predict Recurrence after Resection of Grade 1 and 2 Nonfunctioning Pancreatic Neuroendocrine Tumors.

BACKGROUND: Despite the low recurrence rate of resected nonfunctional pancreatic neuroendocrine tumors (NF-pNETs), nearly all patients undergo long-term surveillance. A prediction model for recurrence may help select patients for less intensive surveillance or identify patients for adjuvant therapy. The objective of this study was to assess the external validity of a recently published model predicting recurrence within 5 years after surgery for NF-pNET in an international cohort. This prediction model includes tumor grade, lymph node status and perineural invasion as predictors. METHODS: Retrospectively, data were collected from 7 international referral centers on patients who underwent resection for a grade 1-2 NF-pNET between 1992 and 2018. Model performance was evaluated by calibration statistics, Harrel's C-statistic, and area under the curve (AUC) of the receiver operating characteristic curve for 5-year recurrence-free survival (RFS). A sub-analysis was performed in pNETs >2 cm. The model was improved to stratify patients into 3 risk groups (low, medium, high) for recurrence. RESULTS: Overall, 342 patients were included in the validation cohort with a 5-year RFS of 83% (95% confidence interval [CI]: 78-88%). Fifty-eight patients (17%) developed a recurrence. Calibration showed an intercept of 0 and a slope of 0.74. The C-statistic was 0.77 (95% CI: 0.70-0.83), and the AUC for the prediction of 5-year RFS was 0.74. The prediction model had a better performance in tumors >2 cm (C-statistic 0.80). CONCLUSIONS: External validity of this prediction model for recurrence after curative surgery for grade 1-2 NF-pNET showed accurate overall performance using 3 easily accessible parameters. This model is available via www.pancreascalculator.com.

Synthesis and evaluation of [18F]cinacalcet for the imaging of parathyroid hyperplasia.

INTRODUCTION: Parathyroid hyperplasia is a disease characterized by overactive parathyroid glands secreting increased levels of parathyroid hormone. Surgical removal of the parathyroid glands is the standard treatment but requires precise pre-operative localization of the glands. However, currently available imaging modalities show limited sensitivity. Since positron emission tomography (PET) is a molecular imaging technique with high accuracy and sensitivity, our aim was to develop a new PET tracer for overactive parathyroid glands imaging by radiolabelling cinacalcet, a drug binding to the calcium-sensing receptor of the parathyroid glands. METHODS: [18F]Cinacalcet was synthesized by copper-catalysed [18F]trifluoromethylation of a boronic acid precursor using high molar activity [18F]fluoroform. Ex vivo biodistribution and metabolism were evaluated in 12 healthy male Wistar rats at 5, 15, 45 and 90 min. PET scans were performed at baseline and after blocking with NPS R-568. RESULTS: [18F]Cinacalcet was obtained in an overall radiosynthesis time of 1 h with a radiochemical purity of 98 ± 1%, a radiochemical yield of 8 ± 4% (overall, n = 7, corrected for decay) and a molar activity of 40 ± 11 GBq/µmol (n = 7, at EOS). The ex vivo biodistribution showed uptake in the thyroid and parathyroid glands as well as in other glands such as adrenals, salivary glands and pancreas. The tracer was rapidly cleared from the blood via liver and kidneys and showed fast metabolism. PET images confirmed uptake in the target organ. However, in a blocking study with NPS R-568 specific binding of [18F]cinacalcet to the CaSR could not be confirmed. CONCLUSIONS: [18F]Cinacalcet was successfully synthesized. First in vivo experiments in healthy rats showed uptake of the tracer in the target organ and fast metabolism, encouraging further in vivo evaluation of this tracer.