Four-dimensional computed tomography as first-line imaging in primary hyperparathyroidism, a retrospective comparison to conventional imaging in a predominantly single adenoma population.

BACKGROUND: To determine the use of four-dimensional CT as first-line imaging compared to the traditional combination of ultrasound and [99mTc]Tc-Sestamibi SPECT. MATERIALS AND METHODS: Retrospective review of preoperative imaging in patients with primary hyperparathyroidism, who underwent parathyroidectomy between 2012 and 2021. In one group, the combination ultrasound and [99mTc]Tc-Sestamibi SPECT was used as first-line imaging (n = 54), in the other group four-dimensional CT was the first-line imaging modality (n = 51). Sensitivity and positive predictive value were calculated on patient, lateralisation and localisation level. The need for additional imaging was also assessed for both groups. RESULTS: Four-dimensional CT had a significantly higher sensitivity compared to the combination of ultrasound/[99mTc]Tc-Sestamibi SPECT on patient and localisation level (70.6% vs. 51.9%, p = 0.049 and 60.8% vs. 35.2%, p = 0.009 respectively). Sensitivity for lateralisation also appeared higher, but did not reach significance (62.7% vs. 44.4%, p = 0.060). Positive predictive value was not significantly higher for four-dimensional CT compared to ultrasound and [99mTc]Tc-Sestamibi SPECT (88.9% vs. 85.7% for lateralisation and 86.1% vs. 67.9% for localisation respectively). Additional imaging was required in 14 patients with four-dimensional CT as first-line imaging (27.4%) consisting of 2 ultrasound/[99mTc]Tc-Sestamibi SPECT and 13 [18F]fluorocholine PET/CT, compared to 24 patients with ultrasound/[99mTc]Tc-Sestamibi SPECT as first-line imaging (44.4%), requiring 22 four-dimensional CT and 9 [18F]fluorocholine PET/CT. CONCLUSIONS: Four-dimensional CT as the sole first-line parathyroid imaging modality had higher sensitivity than the combination of ultrasound and [99mTc]Tc-Sestamibi SPECT, therefore requiring fewer additional procedures. Although the most costly, [18F]fluorocholine PET/CT was the most effective technique to localise parathyroid adenoma in case all other imaging was negative.

Use of [18F]fluorocholine PET/CT in the detection of primary hyperparathyroidism in paediatrics: a case report.

OBJECTIVES: The most common cause of primary hyperparathyroidism (PPH) in children is a parathyroid adenoma. Among this population, PPH exhibits higher levels of morbidity, severity and target organ involvement compared to adults. When there is suspicion of PPH, cervical ultrasound and 99mTc-sestamibi SPECT/CT are the imaging test traditionally indicated. Among adults, the use of [18F]fluorocholine PET/CT has shown a higher sensitivity than ultrasound and [99mTc]sestamibi SPECT/CT, leading to an expanding adoption in recent years. However, its role in paediatrics has not been clearly defined yet. CASE PRESENTATION: The patient is an adolescent female aged 13 years presented with lithiasis. The analytical study revealed elevated PTH, hipovitaminosis D, hypercalcaemia and hypophosphataemia. Due to the suspicion of PPH, cervical ultrasound and 99mTc-sestamibi SPECT/C were performed, failing to identify hyperfunctioning parathyroid glands. We proceeded to carry out a [18F]fluorocholine PET/CT where a hypermetabolic nodular image was identified, compatible with a hyperfunctioning parathyroid adenoma. The patient underwent surgery, resulting in the normalisation of PTH levels. Pathological anatomy confirmed the presence of a parathyroid adenoma. CONCLUSIONS: In cases where conventional imaging tests yield negative results or discrepancies, we suggest the possibility of the use of [18F]fluorocholine PET/CT for the detection of hyperfunctioning parathyroid adenomas.

Bilateral Ovarian Metastases of Hepatocellular Carcinoma Diagnosed with 18F-Fluorocholine PET/CT in a Patient with Endometriosis.

A 47-year-old woman with history of hepatocellular carcinoma was referred for 18F-fluorocholine PET/CT evaluation due to elevated alpha-fetoprotein. The examination showed several peritoneal uptakes and two nodular pelvic foci. Coelioscopic exploration allowed confirmation and resection of multiple peritoneal metastases from hepatocellular carcinoma while pelvic biopsies revealed endometriosis and endosalpingiosis. However, alpha-fetoprotein kept rising: subsequent 18F-fluorodesoxyglucose PET/CT exploration found no pelvic uptake, while 18F-fluorocholine PET/CT revealed intense tracer accumulation in the two pelvic masses corresponding to bilateral ovarian metastases of hepatocellular carcinoma. We highlight the importance of 18F-fluorocholine PET/CT in hepatocellular carcinoma especially in patients with confounding comorbidities such as endometriosis.

Diagnostic and therapeutic impact of PET/CT with 18F-DCFPyL versus 18F-Fluorocholine in initial staging of intermediate-/high-risk prostate cancer: a pilot study.

AIM: To assess the diagnostic and therapeutic impact of PET/CT with 18F-DCFPyL with respect to 18F-Fluorocholine in initial staging of intermediate-/high-risk prostate cancer (PCa). MATERIAL AND METHODS: Patients with recent diagnosis of intermediate-/high-risk PCa without androgen deprivation therapy and previous 18F-Fluorocholine-PET/CT (negative for extraprostatic disease or with oligometastatic disease) were referred to 18F-DCFPyL-PET/CT. Patients' disease characteristic as grade group, D'Amico risk category (intermediate/high), prostate-specific antigen (PSA) closest to PET/CTs and its kinetics were obtained. The overall detection rate (DR) and molecular imaging TNM (miTNM) stage according to the prostate cancer molecular imaging standardized evaluation (PROMISE) criteria were assessed for both radiotracers, and their concordance (Kappa coefficient) was analyzed. The diagnostic and therapeutic impact of 18F-DCFPyL with respect to 18F-Fluorocholine was evaluated. RESULTS: Fifty-eight patients were analyzed (84.5% high-risk). 18F-Fluorocholine showed a higher DR than 18F-DCFPyL of prostate gland involvement (100% versus 93.1%) and pelvic node disease (37.9% versus 31%; k = 0.436, p = 0.001). On the other hand, 18F-DCFPyL-PET/CT showed a higher DR of metastatic disease than 18F-Fluorocholine-PET/CT, 9/58 patients (15.5%): 3 M1a, 5 M1b and 1 M1c) versus 5/58 (8.6%) patients: 1 M1a and 4 M1b), k = 0.426; p = 0.001. No significant association was found between clinical characteristics (grade group, risk category, PSA level and kinetic) and 18F-Fluorocholine or 18F-DCFPyL results. The results of 18F-DCFPyL-PET/CT modified the previously planned treatment compared to 18F-Fluorocholine-PET/CT in 13 patients (22.4%). CONCLUSIONS: 18F-Fluorocholine and 18F-DCFPyL PET/CT showed a similar DR of prostate gland and lymph node involvement, although with moderate concordance for the latter. 18F-DCFPyL was superior to 18F-Fluorocholine in detecting regional and distant metastasis with a therapeutic impact in one of every five patients.

Analysis of intraoperative laboratory measurements and imaging techniques such as Tc-99 m-MIBI SPECT/CT, 18F-fluorocholine PET/CT and ultrasound in patients operated with prediagnosis of parathyroid adenoma.

AIM: The aim of this study is to determine accurately the localization of the adenoma with the imaging methods in the patients, who are planned to be operated on with prediagnosis of parathyroid adenoma. METHOD: In our study, the files of the patients who were considered to have parathyroid adenoma and underwent operation between 2012 and 2020 with the methods such as Tc99m-MIBI SPECT/CT, 18F-fluorocholine PET/CT, and ultrasound, and biochemical examinations were examined retrospectively. RESULTS: In this study, 31 (18.2%) male and 139 (81.8%) female adult patients were included. The sensitivities of localization methods were 82.6% for ultrasound and 78.4% for scintigraphy. Adenoma was localised in the right place in 14 of 15 (93.3%) patients with the 18F-fluorocholine PET/CT method. A statistically significant correlation was found between the sensitivity of scintigraphy, the gland weights (p: 0.002), and phosphor values (p: 0.039). A statistically significant improvement was observed in the intact PTH value (p: 0.001) 15 min after the removal of adenoma. A statistically significant improvement was observed in the serum PTH value (p: 0.001), the serum phosphorus value (p: 0.001), and the serum calcium (p: 0.001) in the first 3 months after the operation. CONCLUSION: Determining localization accurately for the patients enables performing operations with minimally invasive surgery successfully in a shorter time. Also, fewer complications and faster recovery are seen in the patients. It was concluded that studying intraoperative intact PTH and using 18F-fluorocholine PET/CT method for localization give more accurate results for localization and allow having more successful operation outcomes.

A Head-to-Head Comparison of 18F-Fluorocholine PET/CT and Conventional MRI as Predictors of Outcome in IDH Wild-Type High-Grade Gliomas.

(1) Aim: To study the associations between imaging parameters derived from contrast-enhanced MRI (CE-MRI) and 18F-fluorocholine PET/CT and their performance as prognostic predictors in isocitrate dehydrogenase wild-type (IDH-wt) high-grade gliomas. (2) Methods: A prospective, multicenter study (FuMeGA: Functional and Metabolic Glioma Analysis) including patients with baseline CE-MRI and 18F-fluorocholine PET/CT and IDH wild-type high-grade gliomas. Clinical variables such as performance status, extent of surgery and adjuvant treatments (Stupp protocol vs others) were obtained and used to discriminate overall survival (OS) and progression-free survival (PFS) as end points. Multilesionality was assessed on the visual analysis of PET/CT and CE-MRI images. After tumor segmentation, standardized uptake value (SUV)-based variables for PET/CT and volume-based and geometrical variables for PET/CT and CE-MRI were calculated. The relationships among imaging techniques variables and their association with prognosis were evaluated using Pearson's chi-square test and the t-test. Receiver operator characteristic, Kaplan−Meier and Cox regression were used for the survival analysis. (3) Results: 54 patients were assessed. The median PFS and OS were 5 and 11 months, respectively. Significant strong relationships between volume-dependent variables obtained from PET/CT and CE-MRI were found (r > 0.750, p < 0.05). For OS, significant associations were found with SUVmax, SUVpeak, SUVmean and sphericity (HR: 1.17, p = 0.035; HR: 1.24, p = 0.042; HR: 1.62, p = 0.040 and HR: 0.8, p = 0.022, respectively). Among clinical variables, only Stupp protocol and age showed significant associations with OS and PFS. No CE-MRI derived variables showed significant association with prognosis. In multivariate analysis, age (HR: 1.04, p = 0.002), Stupp protocol (HR: 2.81, p = 0.001), multilesionality (HR: 2.20, p = 0.013) and sphericity (HR: 0.79, p = 0.027) derived from PET/CT showed independent associations with OS. For PFS, only age (HR: 1.03, p = 0.021) and treatment protocol (HR: 2.20, p = 0.008) were significant predictors. (4) Conclusions: 18F-fluorocholine PET/CT metabolic and radiomic variables were robust prognostic predictors in patients with IDH-wt high-grade gliomas, outperforming CE-MRI derived variables.

Detection of an undescended parathyroid adenoma with 18F-fluorocholine PET/CT.

Surgical excision of a parathyroid adenoma (PTA) is the only curative treatment for primary hyperparathyroidism (PHP). The transition from routine bilateral neck exploration to minimally invasive parathyroidectomy has been made possible by preoperative location techniques, including molecular imaging. Here, we present a case of a 76-year-old man with PHP who underwent a [18F]fluorocholine PET/CT scan, which showed a rare undescended PTA at the level of the right carotid bifurcation. After a successful minimally invasive parathyroidectomy, a PTA was confirmed, and the parathyroid hormone level normalized within 24 h. We conclude that it is relevant to locate preoperatively a PTA accurately to assist the surgeon to perform a successful minimally invasive parathyroidectomy.

Incidental detection of breast cancer by 18F-fluorocholine PET/CT performed for primary hyperparathyroidism.

We present a case report of incidental detection of breast cancer in a female patient referred for 18F-fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) due to primary hyperparathyroidism. This imaging method was recently shown as more sensitive for the detection of metabolically hyperactive parathyroid glands than neck ultrasound and (2-metoksyizobutyloizonitryl labeled with technetium-99m) [99mTc]MIBI. Increased accumulation of FCH was found in the hyperactive parathyroid gland and unexpectedly in the right breast lesion. The surgery confirmed parathyroid adenoma. One month later right upper medial quadrantectomy confirmed breast carcinoma - a combination of invasive ductal carcinoma and intracystic papillary breast carcinoma. To the best of our knowledge, this is the first reporting of simultaneous detection of parathyroid adenoma and breast cancer by using 18F-fluorocholine PET/CT.

18F-fluorocholine PET/CT and conventional imaging in primary hyperparathyroidism.

PURPOSE: The purpose of this study was to assess the diagnostic capabilities of preoperative conventional imaging (99mTc-MIBI scintigraphy, cervical ultrasonography [CUS]) and 18F-fluorocholine PET/CT (FCH PET/CT) in the detection of hyperfunctioning parathyroid gland in patients with primary hyperparathyroidism (PHPT) used alone or as a single imaging set. MATERIALS AND METHODS: A total of 51 consecutive patients (6 men, 45 women; mean age, 62 ± 11.6 [SD] years; age range: 28-86 years) with biochemically confirmed PHPT who underwent CUS, single-tracer dual phase 99mTc-MIBI scintigraphy and FCH PET/CT were retrospectively included. 99mTc-MIBI scintigraphy were performed immediately after CUS and interpreted by the same operators. FCH PET/CT examinations were interpreted independently by two nuclear medicine physicians. An additional reading session integrating the three imaging modalities read in consensus as a combined imaging set was performed. RESULTS: At surgery, 74 lesions were removed (32 parathyroid adenomas, 38 parathyroid hyperplasia and 4 subnormal glands). Thirty-six patients (71%) had single-gland disease and 15 patients (29%) had multiglandular disease at histopathological analysis. On a patient basis, sensitivity and accuracy of FCH PET/CT, CUS and 99mTc-MIBI scintigraphy for the detection of abnormal parathyroid glands were 76% (95% CI: 63-87%) and 76% (95% CI: 63-87%), 71% (95% CI: 56-83%) and 71% (95% CI: 56-83%), 33% (95% CI: 21-48%) and 33% (95% CI: 21-48%), respectively. The sensitivity of the combined imaging set was 94% (95% CI: 84-99%) and greater than the sensitivity of each individual imaging technique (P ≤ 0.001 for all). CONCLUSION: Our results suggest that CUS, 99mTc-MIBI scintigraphy and FCH PET/CT interpreted as a single imaging set could be the ideal practice to precisely localize parathyroid lesion in patients with PHPT before surgery.

18F-Fluorocholine-PET combined with contrast-enhanced CT for localizing hyperfunctioning parathyroid glands and optimizing surgical treatment in patients with hyperparathyroidism.

PURPOSE: Hyperparathyroidism (HPT) is a common disorder. A cure can only be achieved by removing all diseased glands. It is critical to localize the hyperfunctioning glands exactly to prevent extensive surgical exploration. The number of false negative/inconclusive results in standard imaging techniques is high. We aimed to evaluate the diagnostic accuracy of 18F-Fluorocholine-PET in combination with contrast-enhanced CT (FCH-PET/CT) and its sensitivity in patients with primary, secondary/tertiary, and familial HPT with negative and/or discordant findings in ultrasound and/or 99mTc-sestamibi scintigraphy/SPECT/CT. METHODS: A total of 96 patients with HPT and negative/equivocal conventional imaging were referred for FCH-PET/CT. In this retrospective, single institution study, 69 patients, who have undergone surgery and histopathologic workup, were analyzed. Of the 69 patients included, 60 patients suffered from primary HPT, four from secondary or tertiary HPT, and five from familial HPT. Sensitivities, positive predictive values, and accuracies were calculated. RESULTS: Sensitivity/positive predictive value (PPV) per lesion was 87.5/98.3% for primary HPT, 75/100% for secondary/tertiary HPT and 25/66.7% for familial HPT. Sensitivity/PPV per patient was 91.5/98.2% for primary HPT, 100/100% for secondary/tertiary HPT and 50/100% for familial HPT. All patients showed normalized serum calcium levels in the postoperative period. The follow-up rate was 97%. Of the patients included in the study, 58 of 60 patients with primary HPT, and four of four patients with secondary/tertiary HPT showed normal calcium and parathyroid hormone (PTH) levels after six months and were cured. Of the patients with familial HPT, four of five patients were cured. CONCLUSION: Diagnostic accuracy of 18F-Fluorocholine-PET/CT for patients with pHPT is excellent. 18F-Fluorocholine-PET/CT is a valuable tool for endocrine surgeons to optimize the surgical treatment of patients with hyperparathyroidism.

Combined bone scintigraphy and fluorocholine PET/computed tomography predicts response to radium-223 therapy in patients with prostate cancer.

AIM: To assess the value of bone scintigraphy and 18F-fluorocholine PET/computed tomography (CT) in predicting outcome in patients with prostate cancer and bone metastases treated with 223radium. MATERIALS & METHODS: Retrospective analysis of 48 patients that underwent 223radium therapy. End points were pain relief and overall survival. RESULTS: After therapy, pain relief was observed in 27 patients. Patients without pain relief had more bone lesions at PET/CT than at bone scintigraphy (pretherapy imaging mismatch). In 39 patients who completed treatment protocol, post-therapy alkaline phosphatase and pretherapy imaging mismatch were independent predictors of poor overall survival. CONCLUSION: Patients with more lesions at 18F-fluorocholine PET/CT than at bone scintigraphy had a poor prognosis. The combined imaging approach could be useful to predict outcome after 223radium therapy.

Primary Hyperparathyroidism: Defining the Appropriate Preoperative Imaging Algorithm.

Primary hyperparathyroidism is a common and potentially debilitating endocrine disorder for which surgery is the only curative treatment. Preoperative imaging is always recommended, even in cases of conventional bilateral neck exploration, with a recognized role for 99mTc-sestamibi scintigraphy in depicting ectopic parathyroid lesions. Scintigraphy can also play a major role in guiding a targeted, minimally invasive parathyroidectomy. However, the ability to recognize multiple-gland disease (MGD) varies greatly depending on the imaging protocol used. Preoperative diagnosis of MGD is important to reduce the risks of conversion to bilateral surgery or failure. In this article we discuss imaging strategies before first surgery as well as in the case of repeat surgery for persistent or recurrent primary hyperparathyroidism. We describe a preferred algorithm and alternative options. Dual-tracer 99mTc-sestamibi/123I subtraction scanning plus neck ultrasound is the preferred first-line option. This approach should improve MGD detection and patient selection for minimally invasive parathyroidectomy. Second-line imaging procedures in case of negative or discordant first-line imaging results are presented. High detection rates can be obtained with 18F-fluorocholine PET/CT or with 4-dimensional CT. The risk of false-positive results should be kept in mind, however. Adding a contrast-enhanced arterial-phase CT acquisition to conventional 18F-fluorocholine PET/CT can be a way to improve accuracy. We also briefly discuss other localization procedures, including 11C-methionine PET/CT, MRI, ultrasound-guided fine-needle aspiration, and selective venous sampling for parathyroid hormone measurement.

18F-Fluorocholine PET/CT in Primary Hyperparathyroidism: Superior Diagnostic Performance to Conventional Scintigraphic Imaging for Localization of Hyperfunctioning Parathyroid Glands.

Primary hyperparathyroidism (PHPT) is a common endocrine disorder, definitive treatment usually requiring surgical removal of the offending parathyroid glands. To perform focused surgical approaches, it is necessary to localize all hyperfunctioning glands. The aim of the study was to compare the efficiency of established conventional scintigraphic imaging modalities with emerging 18F-fluorocholine PET/CT imaging in preoperative localization of hyperfunctioning parathyroid glands in a larger series of PHPT patients. Methods: In total, 103 patients with PHPT were imaged preoperatively with 18F-fluorocholine PET/CT and conventional scintigraphic imaging methods, consisting of 99mTc-sestamibi SPECT/CT, 99mTc-sestamibi/pertechnetate subtraction imaging, and 99mTc-sestamibi dual-phase imaging. The results of histologic analysis, as well as intact parathyroid hormone and serum calcium values obtained 1 d after surgery and on follow-up, served as the standard of truth for evaluation of imaging results. Results: Diagnostic performance of 18F-fluorocholine PET/CT surpassed conventional scintigraphic methods (separately or combined), with calculated sensitivity of 92% for PET/CT and 39%-56% for conventional imaging (65% for conventional methods combined) in the entire patient group. Subgroup analysis, differentiating single and multiple hyperfunctioning parathyroid glands, showed PET/CT to be most valuable in the group with multiple hyperfunctioning glands, with sensitivity of 88%, whereas conventional imaging was significantly inferior, with sensitivity of 22%-34% (44% combined). Conclusion:18F-fluorocholine PET/CT is a diagnostic modality superior to conventional imaging methods in patients with PHPT, allowing for accurate preoperative localization.

The role of 18F-FCH PET/CT in patients with uremic hyperparathyroidism compared with 99mTc-sestaMIBI SPECT/CT and ultrasonography.

BACKGROUND: The aim of this study was to evaluate the diagnostic efficacy of 18F-fluorocholine (18F-FCH) PET/CT for uremic hyperparathyroidism (uHPT) compared to 99mTc-sestaMIBI SPECT/CT and ultrasonography (US). METHODS: A total of 17 uHPT patients with stage 5 chronic kidney disease (CKD) were prospectively enrolled. All patients underwent US, 99mTc-sestaMIBI SPECT/CT, and 18F-FCH within 2 months and received surgical treatment. Visual and quantitative methods were used for image analyses. Intraoperative localization and postoperative histological results of the reference standard as well as the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the three modalities were analyzed using Pearson's χ2 tests. In addition, the diagnostic efficacy of 18F-FCH PET/CT for uHPT was evaluated. The relationships between PET parameters and laboratory parameters were assessed using the Spearman correlation coefficient. RESULTS: A total of 63 parathyroid hyperplasia lesions were resected in 17 uHPT patients, and 53 lesions were detected using 18F-FCH PET/CT with no false-positive results. The sensitivity, specificity, accuracy, PPV, and NPV were 84.13%, 100%, 86.49%, 100%, and 52.38%, respectively. In comparison, the corresponding values for 99mTc-sestaMIBI SPECT/CT and US were 63.49%, 90.91%, 67.57%, 97.56%, and 30.30% and 61.90%, 81.82%, 64.86%, 95.12%, and 27.27%, respectively. The volume of hyper-functioning parathyroid glands was significantly different between lesions positive in 18F-FCH PET/CT and negative in 18F-FCH PET/CT (mean volume 1.36 ± 0.55 cm3 vs. 0.83 ± 0.26 cm3; P = 0.019). US misidentified intrathyroidal parathyroid hyperplasia as thyroid nodules in three patients, while 18F-FCH PET correctly identified the anatomy. No significant associations were observed between PET parameters and laboratory parameters in uHPT. CONCLUSION: 18F-FCH PET/CT was more sensitive and accurate for uHPT than 99mTc-sestaMIBI SPECT/CT and US, and had better preoperative diagnostic efficacy, particularly for lesions diagnosed as a thyroid nodule by US.

Segmentation of gliomas in 18F-fluorocholine PET/CT. A multiapproach study. / Segmentación de gliomas con PET/TC con 18F-fluorocolina. Estudio multiaproximación.

AIM: Our aim was two-fold, to study the interobserver agreement in tumour segmentation and to search for a reliable methodology to segment gliomas using 18F-fluorocholine PET/CT. METHODS: 25 patients with glioma, from a prospective and non-randomized study (Functional and Metabolic Glioma Analysis), were included.Interobserver variability in tumour segmentation was assessed using fixed thresholds. Different strategies were used to segment the tumours. First, a semi-automatic tumour segmentation was performed, selecting the best SUVmax-% threshold for each lesion. Next we determined a variable SUVmax-% depending on the SUVmax. Finally a segmentation using a fixed SUVmax threshold was performed. To do so, a sampling of 10 regions of interest (ROI of 2.8cm2) located in the normal brain was performed. The upper value of the sample mean SUVmax±3 SD was used as cut-off. All procedures were tested and classified as effective or not for tumour segmentation by two observer's consensus. RESULTS: In the pilot segmentation, the mean±SD of SUVmax, SUVmean and optimal SUVmax-% threshold were: 3.64±1.77, 1.32±0.57 and 21.32±8.39, respectively. Optimal SUVmax-% threshold showed a significant association with the SUVmax (Pearson=-0.653, p=.002). However, the linear regression model for the total sample was not good, that supported the division in two homogeneous groups, defining two formulas for predicting the optimal SUVmax-% threshold. As to the third procedure, the obtained value for the mean SUVmax background+3 SD was 0.33. This value allowed segmenting correctly a significant fraction of tumours, although not all. CONCLUSION: A great interobserver variability in the tumour segmentation was found. None of the methods was able to segment correctly all the gliomas, probably explained by the wide tumour heterogeneity on 18F-fluorocholine PET/CT.

Baseline 18F-Fluorocholine PET/CT and bone scan in the outcome prediction of patients treated with radium 223 dichloride.

AIM: To establish the utility of baseline 18F-Fluorocholine (FCH) PET/CT and bone scintigraphy (BS) in the outcome prediction of patients with castration-resistant prostate cancer and bone metastases (CRPC-BM) treated with 223Ra. METHODS: Prospective, multicenter and non-randomized study (ChoPET-Rad study). FCH PET/CT and BS were performed before the initiation of 223Ra (basal FCH PET/CT and BS). Bone disease was classified attending the number of lesions in baseline BS and PET/CT. FCH PET/CT was semiquantitatively evaluated. Gleason score, baseline levels of prostate-specific antigen (PSA), alkaline phosphatase and lactate dehydrogenase were determined. Progression-free survival (PFS) and overall survival (OS) since the onset of 223Ra treatment was calculated. PFS was defined by PSA rising. Relations between clinical and imaging variables with PFS and OS were evaluated by Pearson, Mann-Whitney tests and Kapplan-Meier analysis. Univariate and multivariate Cox regression analysis was performed. RESULTS: Forty patients were evaluated. The median PFS and OS were of 3.0 ± 2.3 and 23.0 ± 4.2 months, respectively. 33 patients progressed and 13 died during the follow-up. The extension of the bone disease by FCH PET/CT (p = 0.011, χ2 = 10.63), BS (p = 0.044, χ2 = 8.04), SUVmax (p = 0.012) and average SUVmax (p = 0.014) were related to OS. No significant association was found for the PFS. ROC analysis revealed significant association of SUVmax, average SUVmax and basal PSA with OS. Only therapeutic failure was associated with OS in the multivariate analysis (HR = 3.6, p = 0.04). CONCLUSION: FCH PET/CT and BS had prognostic aim in the prediction of OS. None clinical or imaging variable was able to predict the PFS, probably due to the high rate of progressive disease.

Incidental Detection of Parathyroid Adenoma on Somatostatin Receptor PET/CT and Incremental Role of 18F-Fluorocholine PET/CT in MEN1 Syndrome.

Multiple endocrine neoplasia type 1 (MEN1) syndrome is characterized by combined occurrence of tumors of endocrine glands including the parathyroid, the pancreatic islet cells, and the anterior pituitary gland. Parathyroid involvement is the most common manifestation and usually the first clinical involvement in MEN1 syndrome, followed by gastroentero-pancreatic neuroendocrine tumors (NETs). Here we present a case where the patient initially presented with metastatic gastric NET and a single parathyroid adenoma was detected incidentally on 68Ga-DOTANOC PET/CT done as part of post 177Lu-DOTATATE therapy (PRRT) follow-up. Further 18F-fluorocholine PET/CT showed four adenomas for which the patient subsequently underwent subtotal parathyroidectomy.

Challenging pre-surgical localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism: the added value of 18F-Fluorocholine PET/CT.

PURPOSE: To evaluate the added value of 18F-Fluorocholine (18F-FCH) PET/CT in presurgical imaging of patients with primary hyperparathyroidism (HPT) and challenging localization of the hyper-functioning parathyroid glands. METHODS: We included 27 consecutive patients with primary HPT (19 F; median age: 58 years), with either (i) non-conclusive pre-surgical localization with 99mTc-sestaMIBI scintigraphy and neck ultrasonography (US), (ii) recurrence of previously operated HPT, or (iii) familiar HPT with a suspicion of multiple gland disease. Histological findings and resolution of HPT were considered as the gold standard. RESULTS: 18F-FCH PET/CT was positive in 24/27 patients. Twenty-one patients underwent surgery with 27 resected lesions (14 adenomas, 11 hyperplastic glands, two hyper-functioning histologically normal glands), with resolution of HPT in 19/21 patients (90%). 18F-FCH PET/CT localized 22 lesions in 17/21 patients (per patient: sensitivity 81%, positive predictive value (PPV) 94%; per gland: sensitivity 76%, PPV 85%, specificity 91%, negative predictive value (NPV) 86%). 18F-FCH PET/CT found eight lesions which were undetectable on both 99mTc-sestaMIBI scintigraphy and US. In patients with a familial HPT and/or a multiple gland disease, sensitivity was 100 and 79% on a per-patient and a per-gland analysis respectively, while NPV was 63%. In six patients with a persistence or recurrence of previously treated HPT, 18F-FCH PET/CT localized all lesions, both in sporadic and familiar disease. CONCLUSIONS: 18F-FCH PET/CT is a promising modality in challenging pre-surgical localization of hyper-functioning parathyroid glands, such as inconclusive standard imaging, recurrence after surgery, or suspected multiple gland disease.

18F-Fluorocholine PET/CT in the assessment of primary hyperparathyroidism compared with 99mTc-MIBI or 99mTc-tetrofosmin SPECT/CT: a prospective dual-centre study in 100 patients.

PURPOSE: In this prospective study we compared the accuracy of 18F-fluorocholine PET/CT with that of 99mTc-MIBI or99mTc-tetrofosmin SPECT/CT in the preoperative detection of parathyroid adenoma in patients with primary hyperparathyroidism. We also assessed the value of semiquantitative parameters in differentiating between parathyroid hyperplasia and adenoma. METHODS: Both 18F-fluorocholine PET/CT and 99mTc-MIBI/tetrofosmin SPECT/CT were performed in 100 consecutive patients with biochemical evidence of primary hyperparathyroidism. At least one abnormal focus on either 18F-fluorocholine or 99mTc-MIBI/tetrofosmin corresponding to a parathyroid gland or ectopic parathyroid tissue was considered as a positive finding. In 76 patients with positive findings on at least one imaging modality, surgical exploration was performed within 6 months, and the results were related to histopathological findings and clinical and laboratory findings at 3-6 months as the standard of truth. In 24 patients, no surgery was performed: in 18 patients with positive imaging findings surgery was refused or considered risky, and in 6 patients imaging was negative. Therefore, data from 82 patients (76 undergoing surgery, 6 without surgery) in whom the standard of truth criteria were met, were used in the final analysis. RESULTS: All patients showed biochemical evidence of primary hyperparathyroidism with a mean serum calcium level of 2.78 ± 0.34 mmol/l and parathormone (PTH) level of 196.5 ± 236.4 pg/ml. The study results in 76 patients with verified histopathology and 3 patients with negative imaging findings were analysed. Three of six patients with negative imaging showed normalized serum PTH and calcium levels on laboratory follow-up at 3 and 6 months, and the results were considered true negative. In a patient-based analysis, the detection rate with 18F-fluorocholine PET/CT was 93% (76/82), but was only 61% (50/82) with 99mTc-MIBI/tetrofosmin SPECT/CT. In a lesion-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy of 18F-fluorocholine PET/CT in the detection of parathyroid adenoma were 93.7%, 96.0%, 90.2%, 97.4% and 95.3%, respectively, and of 99mTc-MIBI/tetrofosmin SPECT/CT were 60.8%, 98.5%, 94.1%, 86.3% and 87.7%, respectively. Although 18F-fluorocholine PET-positive adenomatous lesions showed higher SUVmax values than the hyperplastic glands (6.80 ± 3.78 vs. 4.53 ± 0.40) in the semiquantitative analysis, the difference was not significant (p = 0.236). The mean size (measured as the length of the greatest dimension) and weight of adenomas were 15.9 ± 7.6 mm (median 15 mm, range 1-40 mm) and 1.71 ± 1.86 g (median 1 g, range: 0.25-9 g), respectively. Among the analysed parameters including serum calcium and PTH and the size and weight of parathyroid adenomas, size was significantly different between patients with negative 99mTc-MIBI/tetrofosmin SPECT/CT and those with positive 99mTc-MIBI/tetrofosmin SPECT/CT (mean size 13.4 ± 7.6 mm vs. 16.9 ± 7.4 mm, respectively; p = 0.042). CONCLUSION: In this prospective study, 18F-fluorocholine PET/CT showed promise as a functional imaging modality, being clearly superior to 99mTc-MIBI/tetrofosmin SPECT/CT, especially in the detection and localization of small parathyroid adenomas in patients with primary hyperparathyroidism. SUVmax was higher in parathyroid adenomas than in hyperplasia. However, further evaluation of this modality is needed.

Incidental Detection of Parathyroid Adenoma on Somatostatin Receptor PET/CT and Incremental Role of ¹⁸F-Fluorocholine PET/CT in MEN1 Syndrome / 대한핵의학회잡지

Multiple endocrine neoplasia type 1 (MEN1) syndrome is characterized by combined occurrence of tumors of endocrine glands including the parathyroid, the pancreatic islet cells, and the anterior pituitary gland. Parathyroid involvement is the most common manifestation and usually the first clinical involvement inMEN1 syndrome, followed by gastroentero-pancreatic neuroendocrine tumors (NETs). Here we present a case where the patient initially presented with metastatic gastric NET and a single parathyroid adenoma was detected incidentally on ⁶⁸Ga-DOTANOC PET/CT done as part of post ¹⁷⁷Lu-DOTATATE therapy (PRRT) follow-up. Further ¹⁸F-fluorocholine PET/CT showed four adenomas for which the patient subsequently underwent subtotal parathyroidectomy.