Update in imaging tests used for the localization of parathyroid pathology.

Preoperative localization of parathyroid pathology, generally a parathyroid adenoma, can be difficult in some cases due to the anatomical variants that these glands present. The objective of this review is to analyse the different imaging techniques used for preoperative localization of parathyroid pathology (scintigraphy, ultrasound, CT, MRI and PET). There is great variability between the different tests for the preoperative localization of parathyroid pathology. The importance of knowing the different diagnostic options lies in the need to choose the most suitable test at each moment and for each patient for an adequate management of primary hyperparathyroidism (PHP) with surgical criteria.

ML Models Built Using Clinical Parameters and Radiomic Features Extracted from 18F-Choline PET/CT for the Prediction of Biochemical Recurrence after Metastasis-Directed Therapy in Patients with Oligometastatic Prostate Cancer.

Oligometastatic patients at [18F]F-Fluorocholine (18F-choline) PET/CT may be treated with metastasis-directed therapy (MDT). The aim of this study was to combine radiomic parameters extracted from 18F-choline PET/CT and clinical data to build machine learning (ML) models able to predict MDT efficacy. METHODS: Oligorecurrent patients (≤5 lesions) at 18F-choline PET/CT and treated with MDT were collected. A per-patient and per-lesion analysis was performed, using 2-year biochemical recurrence (BCR) after MDT as the standard of reference. Clinical parameters and radiomic features (RFts) extracted from 18F-choline PET/CT were used for training five ML Models for both CT and PET images. The performance metrics were calculated (i.e., Area Under the Curve-AUC; Classification Accuracy-CA). RESULTS: A total of 46 metastases were selected and segmented in 29 patients. BCR after MDT occurred in 20 (69%) patients after 2 years of follow-up. In total, 73 and 33 robust RFTs were selected from CT and PET datasets, respectively. PET ML Models showed better performances than CT Models for discriminating BCR after MDT, with Stochastic Gradient Descent (SGD) being the best model (AUC = 0.95; CA = 0.90). CONCLUSION: ML Models built using clinical parameters and CT and PET RFts extracted via 18F-choline PET/CT can accurately predict BCR after MDT in oligorecurrent PCa patients. If validated externally, ML Models could improve the selection of oligorecurrent PCa patients for treatment with MDT.

Clinical predictors of negative/equivocal SPECT imaging outcomes in primary hyperparathyroidism: Factors calling for 18F-choline-PET.

PURPOSE: For minimally invasive surgery of parathyroid adenomas, exact localization diagnostics are essential. Main imaging modalities used for diagnostics are sonography, SPECT with/without CT (traditional imaging) and 18F-choline-PET. The aim of our study was to identify predictors for inconclusive SPECT imaging and subsequently determine in which cases 18F-choline-PET is needed. METHODS: Retrospective analysis of 138 patients with histologically confirmed primary hyperparathyroidism (pHPT). After sonography, patients underwent SPECT or SPECT/CT imaging, with subsequent 18F-choline-PET in cases of disconcordant results. Logistic regression analysis was used to identify clinical and laboratory factors predictive for negative SPECT results. RESULTS: Sensitivity rates for sonography, SPECT, SPECT/CT, and choline-PET were 47 %, 49 %, 71.7 %, and 97 %, respectively. Logistic regression revealed lower PTH levels (p < 0.001), presence of structural thyroid disease (p = 0.018), and negative sonography (p < 0.001) as predictive of negative/equivocal SPECT outcome. An additional traditional imaging CT scan to a SPECT enhanced detection odds, as did greater adenoma weight. Urolithiasis, osteoporosis, and calcium values as measurement of activity and duration of disease showed no significant association with the detection rate. Furthermore, our study demonstrated that 18F-choline-PET exhibited remarkable sensitivity in detecting adenomas among patients with negative/equivocal SPECT results. CONCLUSION: Our study reveals potential predictive factors for a negative/equivocal SPECT outcome in pHPT. Identifying these factors might allow minimizing futile SPECT examinations and perhaps encourage timely utilization of 18F-choline-PET imaging. Our study reinforces the clinical significance of 18F-choline-PET, especially in complex cases with disconcordant results by conventional parathyroid imaging methods.

Role of 18F-choline and 18F-fluorodeoxyglucose positron emission tomography in combination with magnetic resonance imaging in brachytherapy planning for locally advanced cervical cancer: A pilot study.

Background and purpose: This pilot study aims to describe the advantages of combining metabolic and anatomic imaging modalities in brachytherapy (BT) planning for locally advanced cervical cancer (LACC) and to evaluate the supplementary value of Fluoro(F)-Choline positron emission tomography/computed tomography (PET/CT) in comparison to 18F-fluorodeoxyglucose (FDG) in this setting. Materials and methods: A prospective cohort of six patients with LACC was included in this study. Each patient underwent BT planning CT scan, magnetic resonance imaging (MRI), and both FDG and F-Choline PET/CT scans on the same day, with BT applicators in place. Patients were treated according to the standard of care. Metabolic target volumes (TV) were generated retrospectively and compared with the anatomic volumes using Dice coefficients and absolute volume comparison. Results: The threshold at which the metabolic and anatomic volumes were the most concordant was found to be 35% maximum standardized uptake value (SUV max) for both PET/CT scans. Amongst the six patients in this cohort, three in the FDG cohort and four in the F-Choline cohort were found to have more than ten percent ratio of excess (increase) in their MRI gross tumor volumes (GTV) when incorporating the metabolic information from the PET/CT scans. However, no significant changes were needed in the high risk-clinical target volumes (CTVHR) for both PET tracers. Conclusions: FDG and F-Choline PET/CT scans can substantially modify the BT GTV on MRI, without affecting the CTVHR. F-Choline is potentially more informative than FDG in assessing residual TV, particularly in cases with significant post-radiation inflammatory changes.

Choline PET/CT in recurrent prostate cancer.

Purpose: Biochemical recurrence (BR) occurs in up to 40% of patients with prostate cancer (PCa) treated with primary radical prostatectomy (RP). Choline PET/CT may show, in a single-step examination, the site of tumor recurrence earlier than traditional imaging methods, particularly at low prostate-specific antigen (PSA) levels, thus influencing subsequent treatment. Methods/patients: Patients with recurrent and non-metastatic prostate cancer (nmPCa), who were assessed with choline PET/CT, were included in the analysis. Based on imaging results, the following therapeutic strategies were chosen: radiotherapy to the prostatic bed, androgen deprivation therapy (ADT), and chemotherapy or stereotactic body radiotherapy (SBRT) to either the pelvic lymph nodes or distant metastases. We assessed the impact of age, PSA levels, Gleason score (GS), and adjuvant therapy on oncological outcomes. Results: Data from 410 consecutive nmPCa patients with BR who underwent RP as primary treatment were analyzed. One hundred seventy-six (42.9%) patients had a negative choline PET/CT, and 234 (57.1%) patients resulted positive. In the multivariate analysis, only chemotherapy and PSA at recurrence were significant independent prognostic factors on overall survival (OS). In the PET-positive subgroup, the number of relapses, PSA post-prostatectomy, and chemotherapy impacted on OS. PSA (post-surgery and at recurrence) affected progression-free survival (PFS) in the univariate analysis. In the multivariate analysis, GS, the number of relapse sites, and PSA (post-surgery and at recurrence) were significant prognostic factors for disease-free survival (DFS). Conclusion: Choline PET/CT provides better accuracy than conventional imaging for the assessment of nmPCa with BR after prostatectomy, thereby enabling salvage strategies and improving quality of life.

The Added Value of [18F]Choline PET/CT in Low-Risk Prostate Cancer Staging: A Case Report.

In the management of prostate cancer (PCa), correct staging is crucial in order to assess the right therapeutic approach. [18F]Choline PET/CT has been shown to provide more accurate staging information than conventional imaging approaches. The aim of this paper is to provide a real practice demonstration of the impact of [18F]Choline PET/CT on low-risk prostate cancer staging and clinical management. We report a 64-year-old man with biochemical PCa recurrence diagnosis after transurethral resection of the prostate. The patient, after the detection of an increased level of PSA, underwent multi-parametric prostate magnetic resonance imaging (mpMRI) that did not show evidence of disease. The patient was admitted to perform [18F]Choline PET/CT that showed a macroscopic prostate recurrence. Patient underwent photon external beam radiation therapy (EBRT) treatment, and [18F]Choline PET/CT was also used to define treatment volumes. At 3- and 6-month clinical follow-up evaluations, no late toxicity was detected and a significant reduction in PSA value was shown. Therefore, our case highlights the potential usefulness of [18F]Choline PET/CT for the staging of low-risk prostate cancer and its impact on the management and quality of life of such patients. The presented case should urge the scientific community to enhance larger and multicentric studies, assessing more extensively the potential impact of [18F]Choline PET/CT in this clinical scenario.

Diagnostic Performance of 18F-Choline Positron Emission Tomography/Contrast-Enhanced Computed Tomography in Adenoma Detection in Primary Hyperparathyroidism after Inconclusive Imaging: A Retrospective Study of 215 Patients.

This large, retrospective, single-centre study evaluated the diagnostic performance of 18F-choline positron emission tomography/contrast-enhanced computed tomography (PET/ceCT) in preoperative parathyroid adenoma detection in primary hyperparathyroidism cases after negative/inconclusive ultrasound or other imaging findings. We included patients who underwent surgery and 18F-choline PET/ceCT for inconclusive imaging results between 2015 and 2020. We compared the 18F-choline PET/ceCT results with surgical and histopathological findings and identified the variables influencing the correlation between 18F-choline PET/ceCT and surgical findings. Of 215 enrolled patients, 269 glands (mean lesion size, 10.9 ± 8.0 mm) were analysed. There were 165 unilocular and 50 multilocular lesions; the mean preoperative calcium level was 2.18 ± 0.19 mmol/L. Among 860 estimated lesions, 219 were classified as true positive, 21 as false positive, and 28 as false negative. The per-lesion sensitivity was 88.66%; specificity, 96.57%; positive predictive value, 91.40%; and negative predictive value, 95.39%. The detection and cure rates were 82.0% and 95.0%, respectively. On univariate and multivariate analyses, the maximum standardised uptake value (SUVmax), lesion size, and unilocularity correlated with the pathologic findings of hyperfunctioning glands. 18F-choline PET/ceCT presents favourable diagnostic performance as a second-line imaging method, with SUVmax, lesion size, and unilocularity predicting a high correlation between the 18F-choline PET/ceCT and surgical findings.

Fused 18F-Choline PET/MRI: A potential non-invasive biomarker imaging tool in cerebral vasculitis.

Primary CNS vasculitis is an inflammatory brain disease commonly misdiagnosed affecting the medium and small vessels of the CNS. Due to its broad and non-specific clinical and radiological manifestations; Its diagnosis remains challenging. New diagnostic tools and biomarkers which increase specificity and facilitate the diagnosis for patients with suspected vasculitis are highly desirable to enable physicians to start therapy that can alter its potential aggressive course like immunosuppressant. This case report highlights the potential role of 18F-choline PET/MRI as a novel imaging tool that might help in the right clinical scenario in the diagnosis of this disease. Furthermore, it speculates on its secondary role in monitoring the response to immunosuppressant therapy.

Artificial intelligence-based measurements of PET/CT imaging biomarkers are associated with disease-specific survival of high-risk prostate cancer patients.

OBJECTIVE: Artificial intelligence (AI) offers new opportunities for objective quantitative measurements of imaging biomarkers from positron-emission tomography/computed tomography (PET/CT). Clinical image reporting relies predominantly on observer-dependent visual assessment and easily accessible measures like SUVmax, representing lesion uptake in a relatively small amount of tissue. Our hypothesis is that measurements of total volume and lesion uptake of the entire tumour would better reflect the disease`s activity with prognostic significance, compared with conventional measurements. METHODS: An AI-based algorithm was trained to automatically measure the prostate and its tumour content in PET/CT of 145 patients. The algorithm was then tested retrospectively on 285 high-risk patients, who were examined using 18F-choline PET/CT for primary staging between April 2008 and July 2015. Prostate tumour volume, tumour fraction of the prostate gland, lesion uptake of the entire tumour, and SUVmax were obtained automatically. Associations between these measurements, age, PSA, Gleason score and prostate cancer-specific survival were studied, using a Cox proportional-hazards regression model. RESULTS: Twenty-three patients died of prostate cancer during follow-up (median survival 3.8 years). Total tumour volume of the prostate (p = 0.008), tumour fraction of the gland (p = 0.005), total lesion uptake of the prostate (p = 0.02), and age (p = 0.01) were significantly associated with disease-specific survival, whereas SUVmax (p = 0.2), PSA (p = 0.2), and Gleason score (p = 0.8) were not. CONCLUSION: AI-based assessments of total tumour volume and lesion uptake were significantly associated with disease-specific survival in this patient cohort, whereas SUVmax and Gleason scores were not. The AI-based approach appears well-suited for clinically relevant patient stratification and monitoring of individual therapy.

18F-Fluorocholine Positron Emission Tomography/Computed Tomography is a Highly Sensitive but Poorly Specific Tool for Identifying Malignancy in Thyroid Nodules with Indeterminate Cytology: The Chocolate Study.

Background: Refining the risk of malignancy in patients presenting with thyroid nodules with indeterminate cytology (IC) is a critical challenge. We investigated the performances of 18F-fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) to predict malignancy. Methods: Between May 2016 and March 2019, 107 patients presenting with a thyroid nodule ≥15 mm with IC and eligible for surgery were included in this prospective study. Head-and-neck PET/CT acquisitions were performed 20 and 60 minutes after injection of 1.5 MBq/kg of FCH. PET/CT acquisition was scored positive when maximal standardized uptake value in the IC nodule was higher than in the thyroid background. Pathology was the gold standard for diagnosis. Results: At pathology, 19 (18%) nodules were malignant, 87 were benign, and one was a noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Sensitivity, specificity, accuracy, positive-predictive value (PPV), and negative-predictive value (NPV) of FCH PET/CT in detecting cancer or NIFTP were 90%, 50%, 55%, 29%, and 96% at 20 minutes and 85%, 49%, 67%, 28%, and 94% at 60 minutes, respectively. Higher specificity (58% vs. 33%, p = 0.01) was observed in nononcocytic (n = 72) than in oncocytic IC nodules (n = 35). The pre-PET/CT probability of cancer or NIFTP in Bethesda III-IV nodules was 11% and the post-PET/CT probability was 19% in PET-positives and 0% in PET-negatives. In retrospective analysis, 42% of surgeries would have been unnecessary after PET/CT and 81% before (p < 0.001), resulting in a hypothetical 48% reduction (95% confidence interval [32-64]). Conclusions: FCH PET/CT offers high NPV to reliably exclude cancer in PET-negative IC nodules, but suffers from low PPV, particularly in those with oncocytic cytology. ClinicalTrials.gov identifier: NCT02784223.

18F-choline PET/4D CT in hyperparathyroidism: correlation between biochemical data and study parameters. / PET/TC 4D 18F-colina en el hiperparatiroidismo: correlación entre datos bioquímicos y parámetros del estudio.

BACKGROUND: Hyperparathyroidism (HPT) is characterised by increased levels of parathyroid hormone (HPT), surgical excision being the only definitive curative option. After establishing the need for surgery, it is essential to identify the parathyroid glands in the preoperative period to use a minimally invasive approach. Negativity and / or discrepancy in first-line studies (ultrasound and Tc-99m MIBI parathyroid scintigraphy) require more accurate images to reduce the likelihood of bilateral cervical exploration or reintervention. OBJECTIVES: a) To demonstrate the sensitivity of 18F-fluorocholine (18F-choline) positron emission tomography (PET)/4D computed tomography (4D CT) in HPT. b) To check whether there is a correlation between calcaemia and preoperative PTH versus size and early and late SUVmax (Standardized Uptake Value) of the gland, determined by 18F-choline PET/4D CT and c) to study the behaviour of parathyroid lesions with intravenous contrast (IV). MATERIAL AND METHODS: A total of 28 patients were included between 2016 and 2019 in a single institution. Prospective observational cohort study. Correlations were analysed using Pearson's coefficient for variables with normal distribution and Spearman (rho) for those with non-normal distribution. Anatomopathological analysis was the benchmark standard to determine sensitivity was. A p<.05 was interpreted as significant. STATA 13 software was used. RESULTS: Of the 28 patients who underwent 18F-choline PET/4D CT, 18 were operated. Of the 26 lesions diagnosed by 18F-choline PET/4D CT as suggestive of parathyroid lesions, 23 corresponded to glandular disease (adenoma or hyperplasia) establishing a sensitivity of 88.5%. There was a correlation between the patient's preoperative PTH and the maximum size of the gland on 18F-choline PET/4D CT. (Spearman=.66; p=.0014). The parathyroid lesions showed, in addition to IV contrast enhancement, distinctive behavioural characteristics identified as highly suggestive. CONCLUSIONS: 18F-choline PET/CT 4D is an anatomical and functional study with high sensitivity in patients with HPT with negative or discrepant first-line studies. Preoperative PTH showed a correlation with maximum gland size on 18F-choline PET/CT 4D. Parathyroid lesions behave in a highly suggestive way and are enhanced by IV contrast.

Standardization of acquisition protocols using PET/CT with 18F-Choline in prostate cancer. / Estandarización de los protocolos de adquisición mediante PET/TC con 18F-Colina en el cáncer de próstata.

AIM: To standardize acquisition protocols for 18F-Choline PET/CT to prevent from urine interference, to determine the best time point for the whole-body study, and to assess whether "dual point" acquisition allows for differentiating malignant vs. benign lesions. METHODS: One hundred consecutive patients with prostate cancer were prospectively studied. Immediately after 18F-Choline injection, a pelvis study was acquired, and a whole-body was subsequently obtained 1 and 2 hours p.i. Mean SUVmax was obtained in regions and for every sequential imaging. Mean analysis (χ2) and SUV percentage change (2/1 hours; 1 hours/0 min) were obtained. Metabolic pattern dynamics were assessed: accumulative vs. clearance. Patient follow-up after therapy and directed classification whenever ethically possible were performed. RESULTS: Fifty-three prostate foci, without disturbing urinary activity was ever found on early images. Accumulative pattern in 42, with percentage increase was: 0 min/1 hour: +16.7% (χ20.94); 1/2 hours: +10,0% (χ2 0.83). Clearance pattern in 11, with percentage decrease: 0 min/1 hour: -21.4% (χ20.91): -7.7% (χ20.85), corresponding in 7 to initial staging and in 4 post-radiotherapy biochemical recurrence. Every infradiaphragmatic uptake (n: 24) showed accumulative pattern, with percentage increase of +9.1% (χ20.97), all of them depicted on early imaging. As for 12 supradiaphragmantic uptake, 8 of them showed clearance pattern with percentage decrease: -13.0% (χ20.95). Accumulative pattern showed in 4 of them with percentage increase +13.0% (χ2 0.96), thus being assessed as invasive/malignant. Every bone uptake (n: 18) showed accumulative pattern, with percentage increase: +17.1% (χ20.95), all of them depicted on 1 hour imaging. CONCLUSIONS: As for prostate assessment is concerned, dual point at 0 min/1 hour proved to be the best procedure. As for supradiaphragmatic lymph-nodes detection, dual point with 1/2 hours performed best. As for infradiaphragmatic and bone involvement, as well as for inconclusive findings, the 2 hour imaging increased our diagnostic confidence.

Value of 18F-Choline PET/MRI hybrid technique on the therapeutic approach for patients with prostate cancer treated with prostatectomy and rising prostate specific antigen levels below 1 ng/ml. / Impacto de la tecnología híbrida PET/RM con 18F-colina en la estrategia terapéutica de los pacientes con cáncer de próstata tratados con prostatectomía que presentan elevación del antígeno prostático específico inferior a 1 ng/ml.

OBJECTIVE: To assess the detection rate of 18F-Choline PET/MRI and subsequent changes in therapy approach for patients with prostate cancer treated by prostatectomy and with rising levels of PSA <1 ng/ml. METHODS: Prospective study with our first 36 patients with prostatectomy for prostate cancer and rising levels of PSA, who were referred for an 18F-Choline PET/MRI study. A dual-phase study was acquired after intravenous administration of 185±10% MBq of 18F-Choline: 1) early imaging (immediately after tracer administration) of prostate area (emission PET/Multiparametric MRI). 2) whole-body imaging 1 h after tracer injection (emission PET/MRI: T1, T2, STIR, diffusion). The therapy approach for patients was decided upon the Oncology Committee consensus based on 18F-Choline PET/MRI findings. RESULTS: Twenty out of 36 patients (55.6%) were positive for the 18F-Choline PET/MRI study: 8 (22.2%) within the prostatectomy bed, 7 (19.4%) with infradiaphragmatic lymph nodes, 4 (11.1%) with local recurrence and infradiaphragmatic lymph nodes, and 1 (2.8%) with bone metastasis. Sixteen out of the 36 patients (44.4%) were negative for the 18F-Choline PET/MRI study. 18F-Choline PET/MRI findings had an impact on the therapy approach to follow: 15 patients (41.6%) showed oligometastatic disease which was treated by imaging-guided radiotherapy, 5 (13.9%) with multiple metastatic disease were treated by androgen deprivation therapy, 16 (44.4%) negative were under active surveillance. CONCLUSION: Hybrid 18F-Choline PET/MRI procedure showed a high detection rate for recurrence in prostate cancer patients treated with prostatectomy and rising PSA levels <1 ng/ml, and 18F-Choline PET/MRI findings resulted in a better tailored therapy approach delivered to our patients.

"Real-world" evaluation of 18F-Choline PET/CT practices in prostate cancer patients and impact on changes in therapeutic strategy.

OBJECTIVES: The role of 18F-fluorocholine positron emission tomography/computed tomography (18F-Choline PET/CT) in different clinical situations remains controversial and current practices are very heterogeneous. The aim of this study was to evaluate the "real-world" practice of 18F-Choline PET/CT in patients with prostate cancer and its potential impacts on therapeutic strategy. METHODS AND MATERIALS: This is a retrospective multicenter observational study including 265 consecutive men who underwent 18F-Choline PET/CT for prostate cancer between November 2014 and November 2015. Primary outcome was impact on therapeutic strategy. Secondary outcomes were sensitivity of the 18F-Choline PET/CT and predictive factors associated with positive scans. Statistical analyses comprised Student's t test for continuous variables or chi-squared test for qualitative variables. RESULTS: Median PSA level at the time of PET/CT was 4.19 ng/ml. The decision to perform PET/CT was made after multidisciplinary discussion in 29.8% of cases; most were prescribed by urologists (50.2% of cases). Three main indications were concerned: biochemical recurrence after local treatment (61.1%), initial staging (26.0%), or at the time of progression to castration-resistance (12.9%). Upon biochemical recurrence, 18F-Choline PET/CT allowed identification of ≥1 site(s) with a sensitivity of 80.9%. In multivariate analysis, predictive factors associated with 18F-Choline PET/CT sensitivity were serum PSA level and local treatment type in cases of biochemical recurrence, and PSA doubling time and Gleason score in case of initial staging. 18F-Choline PET/CT results allowed restaging and change in therapeutic strategy in 58.1% of all combined indications. CONCLUSIONS: Indications of 18F-Choline PET/CT were varied. The detection rate of metastatic lesions was suitable, especially when PSA rate was >1 ng/mL. In most cases, 18F-Choline PET/CT led to a change in therapeutic strategy, particularly in the setting of biochemical recurrence.

Fortuitous discovery of non-fluorocholine-fixing papillary carcinoma of vesicular variant of the thyroid.

PURPOSE: Characterization of thyroid nodules is crucial to propose surgical intervention for histological verification. Cervical ultrasound potentially combined with fine needle aspiration is recommended, and fluorocholine positron emission tomography (FCH-PET), commonly used in prostatic cancers, has been evaluated in the diagnosis of thyroid cancers in recent publications. METHODS: We present two cases of patients with multinodular thyroid and primary hyperparathyroidism. The preoperative assessment consisted of an ultrasound, a MIBI scintigraphy and an FCH-PET in favor of a parathyroid adenoma. RESULTS: The imaging examinations pointed to a diagnosis of a parathyroid adenoma. In both cases, papillary thyroid carcinoma, missed by FCH-PET, was discovered incidentally at a distance from the parathyroid adenoma during the surgical procedure. CONCLUSIONS: These are the first descriptions of thyroid papillary carcinoma without preoperative FCH-PET identification. These clinical cases are contrary to recent publications showing a benefit of this examination in the diagnosis of thyroid cancers.

Diagnostic performance of 18F-choline PET-CT in prostate cancer.

OBJECTIVES: To evaluate the diagnostic performance of 18F-choline PETCT in staging prostate cancer (PC) and whether the use of this imaging modality changes the therapeutic decision in patients previously staged by conventional imaging. The secondary aim was to determine the prognostic factors associated with positive choline PETCT findings in both detection of disseminated disease and in changes in the therapeutic indication. MATERIALS AND METHODS: Multicentre, retrospective, observational study of 269 patients diagnosed with PC. Mean age was 69 ± 9.2 years. Of the 269 patients, 62 (23%) had high-risk localized PC (group 1), 118 (43.9%) biochemical failure after radical prostatectomy (group 2), and 89 (33.1%) biochemical failure after radiotherapy (group 3). None of the patients showed clear evidence of distant disease on computed tomography or bone scans. The following potential prognostic factors were assessed: PSA level at diagnosis; primary and secondary Gleason; Gleason score (GS); clinical and pathologic T and N stage; number of positive cylinders in the biopsy; presence of vascular or lymphatic invasion; status of surgical margins; androgen deprivation therapy (ADT); time to biochemical recurrence; and PSA, PSA doubling time (PSADT), and PSA velocity (PSAV) at failure. Univariate and multivariate analyses were performed, and receiver-operating curves calculated. RESULTS: The mean PSA by groups was, group 1: 31.22 ng/ml, group 2: 2.52 ng/ml and group 3: 5.85 ng/ml. The tumor detection rate with 18F-choline PETCT was 74% (group 1: 85.5%, group 2: 55.1% and group 3: 91%). Prognostic factors for positive 18F-choline PETCT were identified only in group 2: PSA at failure and PSADT. 18F-choline PETCT changed the therapeutic indication in 62.8% (group 1: 71%, group 2: 55.2% and group 3: 70.1%). The prognostic factors for a change in treatment were identified only in group 1: secondary Gleason ≤ 4 and GS ≤ 7 and in group 2: PSA at failure, PSA nadir after surgery and pathologic stage N0. 18F-choline PETCT identified lymph node and/or metastatic disease in 32.7% (group 1: 25.8%, group 2: 29.7% and group 3: 41.6%). Prognostic factors for detecting lymph node/metastasis were identified in the group 2: PSA failure ≥ 1.37 ng/ml and PSADT < 4 months and in the group 3: PSADT < 4.6 months and time to failure < 5 years. CONCLUSION: These findings support the clinical use de 18F-choline PET-CT in staging high-risk patients with a secondary Gleason ≤ 4 and GS ≤ 7, in restaging patients with biochemical recurrence after RP if PSA at failure ≥ 1.37 ng/ml or PSADT ≤ 4 months and in patients with biochemical failure after RT, if PSADT ≤ 4.6 months and time to failure < 5 years, because it determines a change in the therapeutic indication.

Primary Hyperparathyroidism Manifesting with Severe Hypercalcemia in a Nonagenarian Man: Pitfall of Common Imaging Techniques, Localization by 18F-Choline Positron Emission Tomography/Computed Tomography and Successful Management with Calcimimetics.

A nonagenarian hypertensive man with chronic kidney disease (CKD) was admitted to the emergency department for gastrointestinal symptoms and worsening symptoms of depression. Severe hypercalcemia (15.3 mg/dL) was found and he was hospitalized. Fluids, loop diuretics and glucocorticoids were administered intravenously, which partially reduced calcium levels over a few days and improved his clinical condition. PTH levels proved increased (306 pg/mL) and 25-OHD levels were reduced; primary hyperparathyroidism (PHPT) was diagnosed. Neck ultrasonography (USG) did not show parathyroid enlargement, nor did 99mTechnetium-sestamibi (SESTAMIBI) scintigraphy reveal hyperfunctioning parathyroid glands. By contrast, 18F-choline PET/CT evidenced a nodule located close to the oesophagus, behind the right thyroid lobe, which proved compatible with a hyperfunctioning parathyroid gland. Since the patient declined surgery, and zoledronate was unfit owing to areas of rarefaction of the jaw, the calcimimetic cinacalcet was started; the dosage was progressively titrated up to 120 mg/day with normalisation of calcium levels over time. PTH levels, however, proved erratic and showed an upward trend over the first year of therapy; however its levels partially decreased following increase of vitamin D levels by replacement therapy. Cinacalcet is a useful and safe drug, which can normalise calcium levels and improve the clinical condition, even in very old patients with severe PHPT who decline or are unfit for surgery.

Intensity-modulated radiotherapy of prostate cancer with simultaneous integrated boost after molecular imaging with 18F-choline-PET/CT : Clinical results and quality of life.

PURPOSE: To analyze clinical results and quality of life of patients with localized prostate cancer after irradiation of the prostate with an 18F-choline-PET/CT-based simultaneous integrated boost (SIB) in comparison to a control group without SIB. METHODS: A total of 134 patients underwent intensity-modulated radiotherapy from 2007-2010. All patients received a total dose of 76 Gy with 2 Gy fractions to the prostate; 67 patients received an additional SIB of 80 Gy. The median follow-up was 65 months. Quality of life was evaluated with the EPIC (Expanded Prostate Cancer Index Composite) questionnaire. RESULTS: Baseline characteristics were similar in both groups (prostate-specific antigen 11 ng/ml vs. 8 ng/ml, p = 0.20, Gleason score <6 in 36% vs. 46%, p = 0.22, with vs. without SIB). No prostate cancer-related death was observed. No significant difference of quality of life scores was found. The largest difference after 5-6 years in comparison to baseline was reported for sexual bother (mean 15 vs. 17 points with vs. without SIB). Mean urinary scores did not decrease. Bowel bother scores changes were larger in the SIB group (mean 5 vs. 2 points, dependent on SIB volume), with increased bowel problems (15 vs. 2% big/moderate problem with bowel movements, p = 0.03). However, a trend towards higher efficacy with SIB resulted (biochemical recurrence-free survival of 92% vs. 85%, p = 0.17). CONCLUSIONS: The first long-term analysis of patients treated with SIB based on molecular imaging with 18-F-choline-PET/CT showed an excellent biochemical recurrence-free survival, but a larger percentage of bowel problems in comparison to the control group.