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We here report 2 cases of castration-resistant prostate cancer (CRPC) observed two times on 11C-choline positron emission tomography computed tomography (PET/CT), which was useful to discriminate viable progressive osteoblastic bone metastasis from benign osteoblastic change induced by the treatment effect and to determine the viability of bone metastases, regardless of whether sclerosis was present or not. Because one case demonstrated disappearance of abnormal 11C-choline uptake of osteoblastic metastatic lesions after abiraterone therapy and no new lesions at other sites, suggesting nonviable bone metastases, we can assume a complete metabolic response. Because the other case demonstrated a decrease in the existing, abnormal 11C-choline uptake of osteoblastic metastatic lesions, but multiple new appearances of osteoblastic and nonosteoblastic lesions with abnormal 11C-choline uptake after radium-223 therapy suggesting multiple viable bone metastases, we can assume progressive metabolic disease. 11C-choline PET/CT could help in assessing the treatment response of bone metastases in patients with metastatic CRPC.

We report a 49-year-old male with castration-resistant prostate cancer (CRPC) with oligometastasis diagnosed by 11C-choline positron emission tomography-computed tomography (PET/CT) and treated with target radiotherapy. In the diagnosis of CRPC (serum prostate-specific antigen [PSA] level of 6.53 ng/mL after maximum androgen blockade (MAB) therapy, high-dose brachytherapy, and external beam radiotherapy), 11C-choline PET/CT detected one tiny obturator lymph node metastasis which fluorodeoxyglucose PET/CT could not detect. He underwent intensity-modulated radiation therapy and MAB was restarted. The PSA value decreased and reached nadir (0.091 ng/mL) after 6 months. The time to PSA progression was 10 months. The choline PET/CT finding and the corresponding local treatment could play an important role in the management sequence of oligoprogressive CRPC.

The aims of the present systematic review were to: (1) assess the role of 18F-fluorocholine (FCH) positron emission tomography (PET) with computed tomography (CT) and PET with magnetic resonance imaging (MRI) in patients with biochemically known hyperparathyroidism; (2) compare the diagnostic performance of FCH PET/CT or PET/MRI with conventional morphological and functional imaging. A literature search until December 2019 was performed in the PubMed, Scopus and Web of Science databases, using the terms “choline” AND “PET” AND “hyperparathyroidism”. The search was conducted with and without the addition of filters (e.g., language: English only; type of article: original article; subjects: humans only) and selecting only articles published in the last 5 years. Twenty-three articles and 1112 patients were considered. Different FCH PET/CT acquisition protocols were adopted across the studies, using dynamic, early or delayed scans. FCH PET/CT proved more accurate than ultrasonography (US) or 99mTc-sestamibi single-photon emission tomography (SPET). PET/MRI also seemed to be more accurate than MRI alone in detecting benign parathyroid lesions. FCH PET/CT is more accurate than conventional morphological and functional imaging modalities (US or SPET) for the detection of benign parathyroid lesions. It could, therefore, be a reliable tool in both primary and recurrent hyperparathyroidism.

One of the most promising imaging techniques in primary hyperparathyroidism is PET/CT with choline-based tracers. To investigate the current evidence of these tracers in localizing parathyroid adenoma, a systematic review was performed. A comprehensive literature search was carried out and eligible studies were analyzed. Data were extracted, the level of evidence was scored, and performance data were pooled to calculate the weighted detection rate. Eleven articles were included in this study. The pooled detection rate was 97 and 94% on per patient-based and per lesion-based analysis, respectively. There was considerable heterogeneity between studies and the level of evidence was determined to be 3a-, following Oxford criteria. Choline PET/CT has shown favorable results in detection of hyperfunctioning parathyroid tissue and may replace conventional technetium-99m-sestamibi scintigraphy in preoperative planning of parathyroid surgery. However, the quality of current evidence is moderate, and additional high-quality studies are needed to confirm these numbers.

Objective Carbon-11-(11C)-choline PET/computed tomography (CT) has shown good results in re-staging of prostate cancer (PCa) with raised serum levels of prostate-specific antigen. Our aim was to evaluate the effect of positive 11C-choline PET/CT results in the therapeutic management of patients with PCa with biochemical relapse (BR) after curative intention treatment. Patients and methods A total of 112 patients with PCa BR and positive 11C-choline PET/CT were retrospectively evaluated. PET/CT was acquired 20 min after intravenous administration of 555–740 MBq of 11C-choline. The therapeutic management after 11C-choline PET/CT was obtained from the clinical records. The minimum follow-up time was 18 months. Results In 80 (71.4%) of 112 patients, 11C-choline PET/CT showed local recurrence of PCa; in 17 (15.2%) patients, distant recurrence; and in 15 (13.4%) patients, local plus distant recurrence. A second malignancy was detected in five (4.5%) patients. The planned therapeutic management was changed as per positive 11C-choline PET/CT result in 74 (66.1%) patients and were treated as follows: 31 (27.7%) patients with HT, combined with other treatments in eight (7.1%), 17 (15.2%) with BT, 13 (11.6%) with external beam radiotherapy, one (0.9%) with RP, and four (3.6%) with chemotherapy. Treatment approach was not modified in 37 (33%) patients. No data was available from one (0.9%) patient. Conclusion Positive 11C-choline PET/CT result had an important effect in the therapeutic management of patients with PCa and BR, leading to a change in the planned approach in two (66.1%) out of three patients. In addition, in 4.5% of the patients, the 11C-choline PET/CT allowed the detection of a second malignancy.

Background The common endocrine disorder primary hyperparathyroidism (PHPT) can be cured by surgery. Preoperative localization of parathyroid adenoma (PTA) by imaging is a prerequisite for outpatient minimally invasive parathyroidectomy (MIP). Compared to inpatient bilateral cervical exploration (BCE) which is performed if imaging is inconclusive, MIP is superior in terms of cure and complication rates and less costly. The imaging procedure F18-choline (FCH) PET/CT outperforms Tc99m-sestaMIBI (MIBI) SPECT/CT for PTA localization, but it is much costlier. The aim of this study is to identify the most efficient first-line imaging modality for optimal patient care in PHPT without added cost to society. Methods We will conduct a multicenter open diagnostic intervention randomized phase III trial comparing two diagnostic strategies in patients with PHPT: upfront FCH PET/CT versus MIBI SPECT/CT. The primary endpoint is the proportion of patients in whom the first-line imaging method results in successful MIP and cure. Follow-up including biological tests will be performed 1 and 6 months after surgery. The main secondary endpoint is the social cost of both strategies. Other secondary endpoints are as follows: FCH PET/CT and MIBI SPECT/CT diagnostic performance, performance of surgical procedure and complication rate, FCH PET/CT inter- and intra-observer variability and optimization of FCH PET/CT procedure. Fifty-eight patients will be enrolled and randomized 1:1. Discussion FCH PET/CT is a highly efficient but expensive imaging test for preoperative PTA localization and costs three to four times more than MIBI SPECT/CT. Whether FCH PET/CT improves patient outcomes compared to the reference standard MIBI SPECT/CT is unknown. To justify its added cost, FCH PET/CT-guided parathyroid surgery should lead to improved patient management, resulting in higher cure rates and fewer BCEs and surgical complications. In the previous phase II APACH1 study, we showed that second-line FCH PET/CT led to a cure in 88% of patients with negative or inconclusive MIBI SPECT/CT. BCE could be avoided in 75% of patients and surgical complication rates were low. We therefore hypothesize that upfront FCH PET/CT would improve patient care in PHPT and that the reduction in clinical costs would offset the increase in imaging costs. Trial registration NCT04040946, registered August 1, 2019. Protocol version Version 2.1 dated from 2020/04/23.

Background Radiomic features are increasingly utilized to evaluate tumor heterogeneity in PET imaging but to date its role has not been investigated for Cho-PET in prostate cancer. The potential application of radiomics features analysis using a machine-learning radiomics algorithm was evaluated to select 18F-Cho PET/CT imaging features to predict disease progression in PCa. Methods We retrospectively analyzed high-risk PCa patients who underwent restaging 18F-Cho PET/CT from November 2013 to May 2018. 18F-Cho PET/CT studies and related structures containing volumetric segmentations were imported in the "CGITA" toolbox to extract imaging features from each lesion. A Machine-learning model has been adapted using NCA for feature selection, while DA was used as a method for feature classification and performance analysis. Results 106 imaging features were extracted for 46 lesions for a total of 4876 features analyzed. No significant differences between the training and validating sets in terms of age, sex, PSA values, lesion location and size (p > 0.05) were demonstrated by the machine-learning model. Thirteen features were able to discriminate FU disease status after NCA selection. Best performance in DA classification was obtained using the combination of the 13 selected features (sensitivity 74%, specificity 58% and accuracy 66%) compared to the use of all features (sensitivity 40%, specificity 52%, and accuracy 51%). Per-site performance of the 13 selected features in DA classification were as follow: T= sensitivity 63%, specificity 83%, accuracy 71%; N= sensitivity 87%, specificity 91% of and accuracy 90%; bone-M= sensitivity 33%, specificity 77% and accuracy 66%. Conclusions An artificial intelligence model demonstrated to be feasible and able to select a panel of 18F-Cho PET/CT features with valuable association with PCa patients' outcome.

Die Nebenschilddrusenszintigrafie nimmt neben der Sonografie einen wichtigen Stellenwert in der praoperativen Lokalisationsdiagnostik von Nebenschilddrusenadenomen ein. Der nuklearmedizinische diagnostische Standard ist bislang die Technetium-99m-Sestamibi-Szintigrafie. Der Einsatz der Positronenemissionstomographie/Computertomographie (PET/CT) mit Markern des Phospholipidmembranmetabolismus (F-18 Cholin) verspricht auf Basis erster Studien hohere Genauigkeit fur die Aufarbeitung des primaren Hyperparathyreoidismus als die konventionelle MIBI-2-Phasen-Szintigrafie in planarer, SPECT oder SPECT/CT Technik. Diese Ubersicht fasst die Ergebnisse jener Studien zusammen, die mit F‑18 Cholin PET/CT durchgefuhrt wurden. Es wurde eine selektive Literaturrecherche in PubMed mit den Stichworten „primary hyperparathyroidism and choline“, „primary hyperparathyroidism and PET“, „parathyroid adenoma and choline“ und „parathyroid adenoma and PET“ durchgefuhrt. Es wurden 6 Studien, die den Einsatz der F‑18 Cholin PET/CT beim Hyperparathyreoidismus evaluierten, identifiziert. Diese schlossen 5 bis 151 Patienten ein. Die Studien belegen, dass die Cholin PET/CT hohe Nachweisraten (80 bis 96 %) fur solitare Nebenschilddrusenadenome aufweist. Vorteile des Verfahrens sind die hohe Sensitivitat auch bei Rezidiveingriffen oder gleichzeitig bestehenden Knotenstrumen, sowie eine exakte anatomische Zuordnung auch von atypisch gelegenen Adenomen. Die Cholin PET/CT ermoglicht bei der Mehrzahl der Patienten mit pHPT eine exakte Lokalisation solitarer Nebenschilddrusenadenome und fuhrt zu einer Verbesserung der praoperativen Lokalisationsdiagnostik. Daraus folgt ein moglichst minimal-invasives chirurgisches Vorgehen mit verringerter Komplikationsrate bei gleichbleibender Erfolgsrate. Die Bewertung der Erfassung der Genauigkeit bei Mehrdrusenerkrankungen bedarf weiterer Studien.

Introduction There is a need for a precise and reliable imaging to improve the management of prostate cancer. In recent years the PET/CT with choline has changed the handling of prostate cancer in Europe, and it is commonly used for initial stratification or for the diagnosis of a biochemical recurrence, although it does not lack limitations. Other markers are being tested, including the ligand of prostate-specific membrane antigen (PSMA), that seems to offer encouraging prospects. The goal of this piece of work was to critically review the role of choline and PSMA PET/CT in prostate cancer. Evidence acquisition A systematic literature review of databases PUBMED/MEDLINE and EMBASE was conducted searching for articles fully published in English on the PET marker in prostate cancer and its clinical application. Evidence synthesis and discussion It seems as 68Ga-PSMA PET/CT is better than PET/CT in prostate cancer to detect primary prostate lesions, initial metastases in the lymph nodes and recurrence. However, further research is required to obtain high-level tests. Also, other PET markers are studied. Moreover, the emergence of a new PET/MR camera could change the performance of PET imaging.

An 84-year-old man with a history of prostate cancer, treated with radiotherapy, presented with an increase in PSA levels. F-choline PET/CT showed foci of increased choline uptake in L4 and L5 vertebrae, suggestive of bone metastases and another focus in the right cerebellopontine angle. A brain MRI revealed a focus of intense contrast enhancement in the same region, consistent with an acoustic neuroma.

144 Background: Despite having well-recognized limitations, urologists often rely on serial PSA testing as a marker for treatment response or disease progression. To determine if PSA was indeed a reliable marker for treatment response or disease progression, we compared PSA levels against C-11 choline PET/CT in the evaluation of patients with advanced prostate cancer treated with second generation hormonal therapy (2nd-HT). Methods: We retrospectively identified 239 patients who were undergoing treatment with 2nd-HT (enzalutamide or abiraterone) for advanced prostate cancer. While on treatment, patients underwent serial PSA testing and C-11 choline PET/ CTs every 3 – 6 months. Paradoxical response was defined as increasing blood pool-corrected SUVmax of known choline-avid lesions and/or identification of new choline-avid lesions, despite stable or down-trending PSA. Results: Median (IQR) age was 70.4(64.3 – 75.7) years and median (IQR) primary Gleason Score was 8 (7 – 9). In our study, 19% of patients (n = 46/239) who were receiving 2nd-HT exhibited paradoxical response. Median (IQR) PSA and corrected SUVmax at baseline evaluation were 1.3 ng/mL (0.3 – 12.8 ng/mL) and 3.5 (1.8 – 5.8), respectively. Median (IQR) PSA and corrected SUVmax at the time of paradoxical response were 0.4 ng/mL (0.1 – 5.4 ng/mL) and 4.5 (2.8 – 6.8), respectively. The median duration of 2nd-HT treatment prior to detection of paradoxical response was 4.8 months (2.9 – 10.1 months). No significant difference was noted between patients receiving enzalutamide versus abiraterone (p = 0.35). Independent predictors of paradoxical response were prior primary systemic treatment (i.e. hormonal/chemo-hormonal therapy versus local therapy) and patient’s age at time of 2nd-HT initiation on univariate and multivariate analysis. Conclusions: Our retrospective review demonstrated prostate cancer disease progression discordant with PSA down-trending in 19% of patients receiving 2nd-HT. We conclude that in this subset of patients with advanced prostate cancer, PSA may not be a reliable marker of treatment response of disease progression, and routine radiographic evaluation in these patients is warranted.

Background: To determine and compare the diagnostic accuracy of fluoride-PET/CT (NaF-PET/CT), choline-PET/CT, whole-body bone SPECT/CT (WB-SPECT/CT) and whole-body MRI (WB-MRI) for the detection of bone metastases in patients with prostate cancer. Methods: From April 2014 to April 2016, 230 patients with prostate cancer referred for bone imaging were included in the study and underwent three index tests: A routine NaF-PET/CT, a WB-MRI, and half of the patients a WB-SPECT/CT and the other half of the patients a choline-PET/CT. Experienced specialist assessed whether 0, 1–5 or > 5 bone metastases were present. In the absence of a histological reference standard, the final diagnosis was determined by an expert panel based on a review of the index tests, patient files and clinical follow-up images for a minimum of 1.5 years. Results: Two hundred thirteen patients constituted the final study population. Sixty-two patients (29%) were classified with metastatic bone disease as their final diagnosis. The proportion of patients misclassified was (false positive vs false negative): NaF-PET/CT 5% vs 1%, choline-PET/CT 1% vs 1%, WB-SPECT/CT 6% vs 0% and WB-MRI 7% vs 3%. Patient-based diagnostic performances were (sensitivity, specificity, overall accuracy): NaF-PET/CT (95%, 93%, 93%), choline-PET/CT (97%, 99%, 98%), WB-SPECT/CT (100%, 91%, 94%) and WB-MRI (89%, 90%, 90%). No significant differences in the diagnostic performances were detected. A trend towards overestimating the number of bone metastases was observed for NaF-PET/CT only (p = 0.04). Conclusions: All three nuclear medicine methods and WB-MRI had favourable diagnostic performances for the detection of bone metastases with no significant difference between them.

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Aim To evaluate the efficacy of single time-point half-body (skull base to thighs) fluorine-18 choline positron emission tomography-computed tomography (PET-CT) compared to a triple-phase acquisition protocol in the detection of prostate carcinoma recurrence. Materials and methods Consecutive choline PET-CT studies performed at a single tertiary referral centre in patients with biochemical recurrence of prostate carcinoma between September 2012 and March 2017 were reviewed retrospectively. The indication for the study, imaging protocol used, imaging findings, whether management was influenced by the PET-CT, and subsequent patient outcome were recorded. Results Ninety-one examinations were performed during the study period; 42 were carried out using a triple-phase protocol (dynamic pelvic imaging for 20 minutes after tracer injection, half-body acquisition at 60 minutes and delayed pelvic scan at 90 minutes) between 2012 and August 2015. Subsequently following interim review of diagnostic performance, a streamlined protocol and appropriate-use criteria were introduced. Forty-nine examinations were carried out using the single-phase protocol between 2015 and 2017. Twenty-nine (69%) of the triple-phase studies were positive for recurrence compared to 38 (78%) of the single-phase studies. Only one patient who had a single-phase study would have benefited from a dynamic acquisition, they have required no further treatment or imaging and are currently under prostate-specific antigen (PSA) surveillance. Conclusion Choline PET-CT remains a useful tool for the detection of prostate recurrence when used in combination with appropriate-use criteria. Removal of dynamic and delayed acquisition phases reduces study time without adversely affecting accuracy. Benefits include shorter imaging time which improves patient comfort, reduced cost, and improved scanner efficiency.

Owing to their superior uptake and higher detection rate, PSMA-labelled radioligands have largely replaced choline in routine clinical imaging of recurrent prostate cancer (PCa). Nevertheless, even at high PSA values, a small number of patients can present with PSMA negative prostate cancer (PC) lesions. For such patients choline PET continues to play an important role.

Purpose This prospective pilot study was aimed to evaluate ¹¹C-choline PET/CT (choline) as a tool for localization of parathyroid adenoma (PTA). Methods Forty patients with biochemical hyperparathyroidism underwent choline and ⁹⁹mTc-MIBI imaging within a median interval of 56 days. Choline and MIBI images were analyzed and correlated with each other, with additional modalities such as ultrasound, CT, MRI, and with surgical findings, when available. Results Thirty-seven of forty cases were choline-positive, and 3 were choline-negative. Choline uptake on PET was identified with corresponding nodules on CT of the PET/CT, yielding precise localization. Twenty of thirty-seven foci were located in typical sites in the neck, and 17 were ectopic. Clear visualization of PTA was achieved in 33 of 37, whereas findings in 4 cases were suspicious for PTA. MIBI was positive in 33 of 40 cases (22 clearly positive, 11 suspicious). In 29 of 40 cases, choline and MIBI were concordant, but choline findings were clearer in 9 of these 29 studies.At the time of writing, 27 patients had undergone surgery. In 24 cases, there was complete matching of choline with surgical findings of PTA. Overall in 23 cases, both choline and MIBI matched surgical findings of PTA. In 1 case, PTA was correctly localized on choline but not on MIBI, and in 2 cases, neither choline nor MIBI corresponded to the surgical findings. Conclusions These preliminary results indicate that the combined functional and anatomical modality of choline PET/CT is a promising tool for PTA localization, providing clearer images than MIBI, equal or better accuracy, and quicker and easier acquisition.

Background: In patients with bladder cancer (BCa) preoperative staging with 11C-choline positron emission tomography-computed tomography (PET/CT) could be used to derive prognostic information and hence stratify patients preoperatively with respect to disease management. Methods: From June 2004 to May 2007, 44 patients with localized BCa were staged with 11C-choline PET/CT before radical cystectomy. The results of imaging were correlated to overall survival (OS) and cumulative incidence of cancer-specific death (CSD). Results: There was no statistically significant difference in OS and CSD between the patient groups when stratified for organ-confined versus non-organ-confined disease or lymph node involvement defined by either 11C-choline PET/CT (OS: p = 0.262, hazard ratio [HR] = 1.60; p = 0.527, HR = 0.76; CSD: p = 0.144, HR = 2.25; p = 0.976, HR = 0.98) or CT (OS: p = 0.518, HR = 1.34; p = 0.228, HR = 1.67; CSD: p = 0.323, HR = 1.90; p = 0.136, HR = 2.38). The limitation of this study is the small number of included patients. Conclusion: In our prospective trial neither CT nor 11C-choline PET/CT were able to sufficiently predict OS or CSD in BCa patients treated with radical cystectomy albeit trends and moderately increased HRs could be demonstrated without significant differences between CT or 11C-choline PET/CT. However, these trends might prove statistically significant in bigger patient cohorts. Therefore initial transsectional imaging might be of clinical relevance in respect to prognosis and could play a role in the counseling of BCa patients.

Background: The aim of this work was to assess the use of prostate-specific membrane antigen (PSMA)-labelled radiotracers in detecting the recurrence of prostate cancer. PSMA is thought to have higher detection rates when utilized in positron emission tomography (PET)/computed tomography (CT) scans, particularly at lower prostate-specific antigen (PSA) levels, compared with choline-based scans. Methods: A systematic review was conducted comparing choline and PSMA PET/CT scans in patients with recurrent prostate cancer following an initial curative attempt. The primary outcomes were overall detection rates, detection rates at low PSA thresholds, difference in detection rates and exclusive detection rates on a per-person analysis. Secondary outcome measures were total number of lesions, exclusive detection by each scan on a per-lesion basis and adverse side effects. Results: Overall detection rates were 79.8% for PSMA and 66.7% for choline. There was a statistically significant difference in detection rates favouring PSMA [OR (M–H, random, 95% confidence interval (CI)) 2.27 (1.06, 4.85), p = 0.04]. Direct comparison was limited to PSA < 2 ng/ml in two studies, with no statistically significant difference in detection rates between the scans [OR (M–H, random, 95% CI) 2.37 (0.61, 9.17) p = 0.21]. The difference in detection on the per-patient analysis was significantly higher in the PSMA scans ( p < 0.00001). All three studies reported higher lymph node, bone metastasis and locoregional recurrence rates in PSMA. Conclusions: PSMA PET/CT has a better performance compared with choline PET/CT in detecting recurrent disease both on per-patient and per-lesion analysis and should be the imaging modality of choice while deciding on salvage and nonsystematic metastasis-directed therapy strategies.

Purpose The aims of the study were (a) to evaluate the diagnostic role, by means of positive detection rate (PDR), of 18F-choline (CH) positron emission tomography (PET)/CT in patients with prostate cancer treated with radiotherapy, with curative intent, and suspicion of relapse during follow-up, (b) to correlate the PDR with trigger prostate-specific antigen (PSA), (c) to investigate the possible influence of androgen deprivation therapy (ADT) at the time of scan on PDR and (d) to assess distribution of metastatic spread.

PURPOSE: To compare the accuracy of 18F-FACBC and 11C-choline PET/CT in patients radically treated for prostate cancer presenting with biochemical relapse. METHODS: This prospective study enrolled 100 consecutive patients radically treated for prostate cancer and presenting with rising PSA. Of these 100 patients, 89 were included in the analysis. All had biochemical relapse after radical prostatectomy (at least 3 months previously), had 11C-choline and 18F-FACBC PET/CT performed within 1 week and were off hormonal therapy at the time of the scans. The two tracers were compared directly in terms of overall positivity/negativity on both a per-patient basis and a per-site basis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated for both the tracers; follow-up at 1 year (including correlative imaging, PSA trend and pathology when available) was considered as the standard of reference. RESULTS: In 51 patients the results were negative and in 25 patients positive with both the tracers, in eight patients the results were positive with 18F-FACBC but negative with 11C-choline, and in five patients the results were positive with 11C-choline but negative with 18F-FACBC. Overall in 49 patients the results were false-negative (FN), in two true-negative, in 24 true-positive (TP) and in none false-positive (FP) with both tracers. In terms of discordances between the tracers: (1) in one patient, the result was FN with 11C-choline but FP with 18F-FACBC (lymph node), (2) in seven, FN with 11C-choline but TP with 18F-FACBC (lymph node in five, bone in one, local relapse in one), (3) in one, FP with 11C-choline (lymph node) but TP with 18F-FACBC (local relapse), (4) in two, FP with 11C-choline (lymph nodes in one, local relapse in one) but FN with 18F-FACBC, and (5) in three, TP with 11C-choline (lymph nodes in two, bone in one) but FN with 18F-FACBC. With 11C-choline and 18F-FACBC, sensitivities were 32 % and 37 %, specificities 40 % and 67 %, accuracies 32 % and 38 %, PPVs 90 % and 97 %, and NPVs 3 % and 4 %, respectively. Categorizing patients by PSA level (

The purpose of this study was to evaluate the potential usefulness of [18F]-Choline PET/CT in the restaging of prostate cancer patients, who presented a rising PSA.We evaluated 170 prostate cancer patients, previously radically treated, that were referred for restaging with [18F]-Choline PET/CT.A total of 129 patients (median PSA 4.29 ng/ml at relapse) showed one or more areas of high uptake on PET/CT scan, while 41 patients with a median PSA of 1.07 ng/ml at relapse showed negative PET/CT scans. No false negative was found, while 31 patients were identified as false positive. Specificity of Choline PET/CT in our series was 56.9 %, while sensibility was 100 %. At the time of restaging, a PSA value superior or equal to 1 ng/ml was found to be a statistically significant predictive factor of PET positivity, either at the univariate (p0.0001) and at the multivariate analysis (p0.0001).Based on our findings, [18F]-Choline PET/CT is confirmed as a useful diagnostic tool to detect early recurrence, in patients with increasing PSA after primary treatment. However, in case of a mild increase in PSA, positive results must be validated with other techniques, as specificity and positive predictive value of [18F]-Choline PET/CT decrease with the lower values of PSA.

Introduction.11C-choline-PET/CT is a promising technique for detection/restaging of patients with biochemical failure (BF) after curative therapy for prostate cancer (PCA). The aim of this paper was to evaluate the PSA response in patients with BF after radical prostatectomy (RP) who underwent secondary lymphadenectomy (LAD) due to11C-choline-PET/CT findings.Material and Methods. Eight patients with BF and positive lymph nodes in11C-choline-PET/CT after RP were retrospectively included in the study. Extended LAD until the common iliac arteries was performed in all patients.Results. Six of 8 patients had histologically proven lymph node metastases. Four patients showed an initial PSA reduction after LAD, and in 4 patients the PSA increased. Two of the latter had no histological lymph node metastases.Conclusions. Because 50% of our patients showed an initial PSA response, our data suggest that positive11C-choline-PET/CT after RP and BF could help to select patients that could benefit from secondary LAD.

Several studies investigated the potential roles of imaging modalities in prostate cancer patients for the evaluation of intra-prostatic disease, stage and restage. However no precise guidelines exist about the use of imaging modalities, in particular about the role of PET/CT hybrid imaging. Considering the results of the literature and our experience, we tried to summarize the main applications of choline positron emission tomography (PET) in prostate cancer patients. The use of choline PET/CT for initial diagnosis and staging is not recommended as a first-line method. Instead the main and important application of choline PET/CT is represented by the restaging of the disease in case of biochemical relapse for the detection of lymph node and distant recurrence. In particular choline PET/CT could play a crucial role as first diagnostic procedure in prostate cancer patients who show a fast growing Prostate Specific Antigen (PSA) kinetics.

TO THE EDITOR: I have read with great interest the paper by Piccardo et al. ([1][1]) and the editorial by Ceci et al. ([2][2]) recently published in your journal. After a careful analysis of the published data, some comments seem necessary. First, a specific 18F-choline acquisition protocol would

Apply measurability criteria based on the response evaluation criteria in solid tumors (RECIST) to lesions found on (18)F-choline positron emission tomography (PET)/computerized tomography (CT) in patients with hormone refractory prostate cancer.Whole-body PET followed by CT or in-line PET/CT using 3.3-4 MBq/kg of (18)F-choline was performed prospectively on 30 patients with prostate cancer, castrate testosterone levels, and rising post-treatment prostate specific antigen (PSA) levels. Lesions demonstrating increased (18)F-choline uptake were classified as measurable or non-measureable based on RECIST.Three patients were known previously to have RECIST measurable lesions, 10 patients had metastatic findings on radionuclide bone scan, and 17 patients had elevated serum PSA level as the only evidence of disease. Lesions demonstrating increased (18)F-choline uptake were found in 28 (93%) patients. Thirty-eight PET/CT lesions from 14 patients were measurable by RECIST. Lymph node maximum standardized uptake value (SUV(max)) correlated with lymph node diameter (Pearson r = 0.44, p0. 001). RECIST measurable lymph node SUV(max) was significantly higher than that of non-measurable nodes (8.1 vs. 3.7, p0.0001). Detection of skeletal, prostatic, or RECIST-compatible lesions was more likely with a PSA level greater than 4.0 ng/ml (Fisher exact p = 0.0005).Lesions detected with (18)F-choline PET/CT are frequently measurable by RECIST at baseline. Therefore, it may be feasible to include comparisons to RECIST in evaluations of (18)F-choline as a therapeutic response marker for hormone refractory prostate cancer.

The present study was conducted to clarify the role of carbon-11 choline ((11)C-choline) positron emission tomography (PET)/computed tomography (CT) in the management of uterine carcinoma.Twenty-two patients who underwent (11)C-choline PET/CT and pelvic MRI were evaluated retrospectively. The images were reviewed by a board-certified radiologist and a nuclear medicine specialist who were unaware of any clinical information, and a consensus was reached. Diagnostic accuracy of PET/CT was evaluated for staging. The reference standard consisted of histological examination (n = 17) and follow-up conventional CT (n = 5). In five patients with cervical carcinoma, (11)C-choline PET/CT was performed before and after treatment that consisted of cisplatin infusion and subsequent radiotherapy. Standardized uptake value (SUV) was compared with uni-dimensional and volumetric measurements that were made on magnetic resonance images (MRI) before and after treatment.Based on PET/CT interpretations, the reviewers correctly classified T stage in 8 patients (47%), N stage in 21 patients (96%), M stage in 20 patients (91%), and TNM stage in 15 patients (88%). Tumor size, volume, and SUV decreased after treatment in five patients with cervical carcinoma. Using the Pearson correlation test, a significant correlation was found between the reduction rate of SUV and reduction rate of tumor volume.(11)C-choline PET/CT is an accurate means for the management of patients with uterine carcinoma. The combination of (11)C-choline PET/CT and MRI increases the accuracy of staging in patients with uterine carcinoma.

Introduction To evaluate the detection rate of positive choline PET–CT and its clinical role in assisting with management decisions and the correlation between positive choline PET–CT and clinical/pathological parameters in prostate cancer patients with biochemical relapse following radical prostatectomy. Methods This was a longitudinal observational pilot study of 34 patients who received choline PET–CT scans with biochemical relapse after radical prostatectomy. Variables including peak PSA, PSA doubling time (DT), Gleason score, age, initial PSA at diagnosis, use of ADT prior to PET and initial clinical staging were statistically analysed to assess for independent predictive factors for positive PET findings. Results Choline PET–CT was positive in 38.2% of patients (13/34). The only statistically significant predictor for positive PET–CT was the use of ADT prior to PET–CT, with OR 18.7 (95% CI, 2.87–122.45), P

INTRODUCTION AND OBJECTIVES: Recently, Glu-NH-CONH-Lys-(Ahx)-[(68)Ga(HBED-CC)] as a novel 68Gallium-labelled ligand of the prostate-specific membrane antigen (68Ga-HBEDPSMA) has been introduced for the diagnostic evaluation of prostate cancer (PCa) patients. The aim of this study was to evaluate the accuracy of preoperative 68Ga-HBED-PSMA PET with the results of postoperative histological findings after radical prostatectomy (RP) and pelvine template lymph node (LN) dissection with regard to metastatic LN involvement. METHODS: 92 consecutive patients with intermediate to highrisk PCa patients were included. All patients received 68Ga-HBEDPSMA PET hybrid imaging prior to surgery. Pelvine template LN dissection was performed according to 8 predefined anatomical fields. In all patients LN involvement was evaluated in a blinded fashion according to a 5-point scale (1 1⁄4 metastatic; 2 1⁄4 probably metastatic; 3 1⁄4 equivocal; 4 1⁄4 probably benign; 5 1⁄4 benign) on a patientand field-based manner and correlated to postoperative histological analysis. RESULTS: Due to lacking PSMA expression of the primary tumor 4 patients were excluded from further analysis. In total, 20 patients showed metastatic LN. 68Ga-HBED-PSMA PET detected 15 out of 20 patients with histological proven metastatic LN (sensitivity: 75.0%) and correctly classified all 68 patients without histological evidence of LN metastases (specificity: 100%; accuracy 94.3%; PPV: 100%; NPV: 93.2%). 5 patients without evidence of metastatic LN on imaging showed only small metastases in single LN (3 patients with one positive LN, 2 patients with two LN). In total, 470 anatomical fields could be analysed (52 with LN metastases). Sensitivity, specificity, accuracy, PPV and NPV for the field-based analysis were calculated as 73.1%, 98.6%, 95.7%, 86.4% and 96.7%, respectively. CONCLUSIONS: 68Ga-HBED-PSMA PET hybrid imaging shows a high sensitivity as well as superb specificity and accuracy for lymph node staging in intermediate to high-risk PCa patients and might replace current standard imaging (sole MRI, CT or PET using FDG or choline-based tracers) in the future.

An early and correct diagnosis together with accurate staging of prostate cancer is necessary in order to plan the most appropriate treatment strategy. Morphological imaging modalities such as transrectal ultrasonography (TRUS), CT, and MRI can have some limitations regarding their accuracy for primary diagnosis and staging of prostate cancer; for instance, they have limited specificity in differentiating cancer from benign prostatic conditions and, by using size as the only criterion to characterize lymph node metastases, they might not be accurate enough for tumour characterization. In this scenario, PET-CT with (11)C-labelled or (18)F-labelled choline derivatives provides morphological and functional characterization and could overcome the limitations of the conventional imaging techniques. PET-CT is one of the most investigated molecular imaging modalities for prostate cancer diagnosis and staging. Currently, the main investigations on the role of PET-CT in the diagnosis and staging of prostate cancer have been performed on a retrospective basis and this type of analysis might be one of the main reasons why different results regarding its diagnostic accuracy have been reported.