Improved Survival after Transarterial Radioembolisation for Hepatocellular Carcinoma Gives the Procedure Added Value.

BACKGROUND: Transarterial Radioembolisation (TARE) requires multidisciplinary experience and skill to be effective. The aim of this study was to identify determinants of survival in patients with hepatocellular carcinoma (HCC), focusing on learning curves, technical advancements, patient selection and subsequent therapies. METHODS: From 2005 to 2020, 253 patients were treated. TARE results achieved in an initial period (2005-2011) were compared to those obtained in a more recent period (2012-2020). To isolate the effect of the treatment period, differences between the two periods were balanced using "entropy balance". RESULTS: Of the 253 patients, 68 were treated before 2012 and 185 after 2012. In the second period, patients had an Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) score of 1 (p = 0.025) less frequently, less liver involvement (p = 0.006) and a lesser degree of vascular invasion (p = 0.019). The median overall survival (OS) of patients treated before 2012 was 11.2 months and that of patients treated beginning in 2012 was 25.7 months. After reweighting to isolate the effect of the treatment period, the median OS of patients before 2012 increased to 16 months. CONCLUSIONS: Better patient selection, refinement of technique and adoption of personalised dosimetry improved survival after TARE. Conversely, sorafenib after TARE did not impact life expectancy.

International recommendations for personalised selective internal radiation therapy of primary and metastatic liver diseases with yttrium-90 resin microspheres.

PURPOSE: A multidisciplinary expert panel convened to formulate state-of-the-art recommendations for optimisation of selective internal radiation therapy (SIRT) with yttrium-90 (90Y)-resin microspheres. METHODS: A steering committee of 23 international experts representing all participating specialties formulated recommendations for SIRT with 90Y-resin microspheres activity prescription and post-treatment dosimetry, based on literature searches and the responses to a 61-question survey that was completed by 43 leading experts (including the steering committee members). The survey was validated by the steering committee and completed anonymously. In a face-to-face meeting, the results of the survey were presented and discussed. Recommendations were derived and level of agreement defined (strong agreement ≥ 80%, moderate agreement 50%-79%, no agreement ≤ 49%). RESULTS: Forty-seven recommendations were established, including guidance such as a multidisciplinary team should define treatment strategy and therapeutic intent (strong agreement); 3D imaging with CT and an angiography with cone-beam-CT, if available, and 99mTc-MAA SPECT/CT are recommended for extrahepatic/intrahepatic deposition assessment, treatment field definition and calculation of the 90Y-resin microspheres activity needed (moderate/strong agreement). A personalised approach, using dosimetry (partition model and/or voxel-based) is recommended for activity prescription, when either whole liver or selective, non-ablative or ablative SIRT is planned (strong agreement). A mean absorbed dose to non-tumoural liver of 40 Gy or less is considered safe (strong agreement). A minimum mean target-absorbed dose to tumour of 100-120 Gy is recommended for hepatocellular carcinoma, liver metastatic colorectal cancer and cholangiocarcinoma (moderate/strong agreement). Post-SIRT imaging for treatment verification with 90Y-PET/CT is recommended (strong agreement). Post-SIRT dosimetry is also recommended (strong agreement). CONCLUSION: Practitioners are encouraged to work towards adoption of these recommendations.

The role of hepatobiliary scintigraphy combined with spect/ct in predicting severity of liver failure before major hepatectomy: a single-center pilot study.

Hepatobiliary scintigraphy (HBS) has been demonstrated to predict post-hepatectomy liver failure (PHLF). However, existing cutoff values for future liver remnant function (FLR-F) were previously set according to the "50-50 criteria" PHLF definition. Methods of calculation and fields of application in liver surgery have changed in the meantime. The aim of this study was to demonstrate the role of HBS combined with single photon emission computed tomography (SPECT/CT) in predicting severity of PHLF, according to the International Study Group of Liver Surgery (ISGLS). All patients submitted to major hepatectomy with preoperative HBS-SPECT/CT between November 2016 and December 2019, were analyzed. Patients were resected according to hepatic volumetry. Receiver operating characteristic (ROC) curve analysis was performed to identify cutoffs of FLR function for predicting PHLF according to ISGLS definition and grading. Of the 38 patients enrolled, 26 were submitted to one-stage hepatectomy (living liver donors = 4) and 12 to two-stage procedures (portal vein embolization = 4, ALPPS = 8). Overall, 18 patients developed PHLF according to ISGLS criteria: 12 of grade A (no change in the patient's clinical management) and 6 of grade B (change in clinical management). ROC analysis established increasingly higher cutoffs of FLR-F for predicting PHLF according to the "50-50 criteria", ISGLS grade B and ISGLS grade A/B, respectively. HBS with SPECT/CT may help to assess severity of PHLF following major hepatectomy. Prospective multicenter trials are needed to confirm the effective role of HBS-SPECT/CT in liver surgery.

FDG-PET assessment and metabolic patterns in Lafora disease.

PURPOSE: To describe cerebral glucose metabolism pattern as assessed by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in Lafora disease (LD), a rare, lethal form of progressive myoclonus epilepsy caused by biallelic mutations in EPM2A or NHLRC1. METHODS: We retrospectively included patients with genetically confirmed LD who underwent FDG-PET scan referred to three Italian epilepsy centers. FDG-PET images were evaluated both visually and using SPM12 software. Subgroup analysis was performed on the basis of genetic and clinical features employing SPM. Moreover, we performed a systematic literature review of LD cases that underwent FDG-PET assessment. RESULTS: Eight Italian patients (3M/5F, 3 EPM2A/5 NHLRC1) underwent FDG-PET examination after a mean of 6 years from disease onset (range 1-12 years). All patients showed bilateral hypometabolic areas, more diffuse and pronounced in advanced disease stages. Most frequently, the hypometabolic regions were the temporal (8/8), parietal (7/8), and frontal lobes (7/8), as well as the thalamus (6/8). In three cases, the FDG-PET repeated after a mean of 17 months (range 7-36 months) showed a metabolic worsening compared with the baseline examination. The SPM subgroup analysis found no significant differences based on genetics, whereas it showed a more significant temporoparietal hypometabolism in patients with visual symptoms compared with those without. In nine additional cases identified from eight publications, FDG-PET showed heterogeneous findings, ranging from diffusely decreased cerebral glucose metabolism to unremarkable examinations in two cases. CONCLUSIONS: FDG-PET seems highly sensitive to evaluate LD at any stage and may correlate with disease progression. Areas of decreased glucose metabolism in LD are extensive, often involving multiple cortical and subcortical regions, with thalamus, temporal, frontal, and parietal lobes being the most severely affected. Prospective longitudinal collaborative studies are needed to validate our findings.

How Do the More Recent Reconstruction Algorithms Affect the Interpretation Criteria of PET/CT Images?

PURPOSE: Recently, a new Bayesian Penalized Likelihood (BPL) Reconstruction Algorithm was introduced by GE Healthcare, Q.Clear; it promises to provide better PET image resolution compared to the widely used Ordered Subset Expectation Maximization (OSEM). The aim of this study is to compare the performance of these two algorithms on several types of findings, in terms of image quality, lesion detectability, sensitivity, and specificity. METHODS: Between September 6th 2017 and July 31st 2018, 663 whole body 18F-FDG PET/CT scans were performed at the Nuclear Medicine Department of S. Martino Hospital (Belluno, Italy). Based on the availability of clinical/radiological follow-up data, 240 scans were retrospectively reviewed. For each scan, a hypermetabolic finding was selected, reporting both for OSEM and Q.Clear: SUVmax and SUVmean values of the finding, the liver and the background close to the finding; size of the finding; percentage variations of SUVmax and SUVmean. Each finding was subsequently correlated with clinical and radiological follow-up, to define its benign/malignant nature. RESULTS: Overall, Q.Clear improved the SUV values in each scan, especially in small findings (< 10 mm), high SUVmax values (≥ 10), and medium/low backgrounds. Furthermore, Q.Clear amplifies the signal of hypermetabolic findings without modifying the background signal, which leads to an increase in signal-to-noise ratio, improving overall image quality. Finally, Q.Clear did not affect PET sensitivity or specificity, in terms of number of reported findings and characterization of their nature. CONCLUSIONS: Q.Clear is an iterative algorithm that improves significantly the quality of PET images compared to OSEM, increasing the SUVmax of findings (in particular for small findings) and the signal-to-noise ratio. However, due to the intrinsic characteristics of this algorithm, it will be necessary to adapt and/or modify the current interpretative criteria based of quantitative evaluation, to avoid an overestimation of the disease burden.

Contrast enhanced magnetic resonance imaging of the foot in horses using intravenous versus regional intraarterial injection of gadolinium.

The use of contrast enhanced magnetic resonance imaging (MRI) for the detection of orthopedic pathologies in equine patients is poorly described. In few studies, enhanced MRI allowed to differentiate active lesions from chronic ones and to classify ambiguous lesions. The aim of this clinical prospective pilot study is to describe and compare the MRI lesions observed in horses with lameness localized to the foot using a single intravenous bolus dose of gadolinium contrast versus regional intraarterial bolus of contrast agent. Ten horses that underwent contrast enhanced MRI were included in the study. Gadolinium was injected intravenously in 3 patients and in 7 horses contrast agent was administered by intraarterial regional delivery. Regions of interest (ROI) were collected from both pre- and post-contrast images and ratios between pre- and post-contrast ROIs were calculated. No adverse reactions were noted after contrast agent injection. Injured structures that revealed greater increase in signal in post-contrast images were the deep digital flexor tendon (DDFT), the navicular spongiosa and the peritendinous tissues. Regional intraarterial administration of gadolinium provided higher ratio of contrast enhancement. Enhanced MRI using both intravenous or intraarterial injection of gadolinium, increased the diagnostic capability of MRI in horses with foot lesions. Nevertheless, regional intraarterial administration of gadolinium was considered the best choice due to the higher signal and lower volumes of contrast agent required.

Yttrium-90 microsphere radioembolization in unresectable intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma is increasing in frequency worldwide, but radical surgical treatment is practicable in 30-40% of cases. The median survival without therapy is about 8 months, increased to 12 months in combination with systemic chemotherapy. Therefore, locoregional therapies, such as, radiofrequency ablation or transarterial chemoembolization have been employed. Radioembolization with yttrium-90 microspheres (90Y-TARE) is a novel intrarterial treatment which could be included in the armamentarium of treatment options, having shown higher median survival (up to 22 months) and low complication rates. Evidence-based algorithms for staging and allocation to treatment should be defined in the future, after robust results obtained through randomized controlled trials, thus establishing the exact role and timing of 90Y-TARE in the treatment protocol of unresectable intrahepatic cholangiocarcinoma.

The Italian multicentre dosimetric study for lesion dosimetry in 223Ra therapy of bone metastases: Calibration protocol of gamma cameras and patient eligibility criteria.

PURPOSE: The aims of this work were to explore patient eligibility criteria for dosimetric studies in 223Ra therapy and evaluate the effects of differences in gamma camera calibration procedures into activity quantification. METHODS: Calibrations with 223Ra were performed with four gamma cameras (3/8-inch crystal) acquiring planar static images with double-peak (82 and 154keV, 20% wide) and MEGP collimator. The sensitivity was measured in air by varying activity, source-detector distance, and source diameter. Transmission curves were measured for attenuation/scatter correction with the pseudo-extrapolation number method, varying the experimental setup. 223Ra images of twenty-five patients (69 lesions) were acquired to study the lesions visibility. Univariate ROC analysis was performed considering visible/non visible lesions on 223Ra images as true positive/true negative group, and using as score value the lesion/soft tissue contrast ratio (CR) derived from 99mTc-MDP WB scan. RESULTS: Sensitivity was nearly constant varying activity and distance (maximum s.d.=2%). Partial volume effects were negligible for object area ⩾960mm2. Transmission curve measurements are affected by experimental setup and source size, leading to activity quantification errors up to 20%. The ROC analysis yielded an AUC of 0.972 and an optimal threshold of CR of 10, corresponding to an accuracy of 92%. CONCLUSION: The minimum calibration protocol requires sensitivity and transmission curve measurements varying the object size, performing a careful procedure standardisation. Lesions with 99mTc-MDP CR higher than 10, not overlapping the GI tract, are generally visible on 223Ra images acquired at 24h after the administration, and possibly eligible for dosimetric studies.

Yttrium-90 radioembolization for unresectable/recurrent intrahepatic cholangiocarcinoma: a survival, efficacy and safety study.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is a rapidly progressing malignancy; only a minority of the tumours can be resected and the palliative regimens have shown limited success. The aim of this study was to assess overall survival (OS), tumour response and the safety of radioembolization with yttrium-90 ((90)Y-TARE) in patients with unresectable/recurrent ICC. METHODS: Survival was calculated from the date of the (90)Y-TARE procedure. Target and overall Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST (mRECIST) and European Association for the Study of the Liver (EASL)-measuring delayed-phase contrast enhancement-treatment responses were assessed at 3 months. RESULTS: The overall median survival was 17.9 months (95% CI: 14.3-21.4 months). Significantly longer survival was obtained in naive patients as compared with patients in whom TARE was preceded by other treatments, including surgery (52 vs 16 months, P=0.009). Significantly prolonged OS was recorded for patients with a response based on mRECIST and the EASL criteria while RECIST responses were not found to be associated with survival. Treatment was well-tolerated, and no mortality was reported within 30 days. CONCLUSIONS: In unresectable ICC, (90)Y-TARE is safe and offers a survival benefit in naive patients, as well as in responders.

High Level of Agreement Between Pretherapeutic 124I PET and Intratherapeutic 131I Imaging in Detecting Iodine-Positive Thyroid Cancer Metastases.

UNLABELLED: The aim of this retrospective study was to assess the level of agreement between PET and scintigraphy using diagnostic amounts of (124)I and therapeutic amounts of (131)I, respectively, in detecting iodine-positive metastases in patients with differentiated thyroid carcinoma. METHODS: The study included patients who underwent PET /: CT 24 and 120 h after administration of approximately 25 MBq of (124)I and subsequently underwent imaging 5-10 d after administration of 1-10 GBq of (131)I. For each patient, the intratherapeutic (131)I imaging comprised a whole-body scintigraphy scan and a SPECT/CT scan of the neck to distinguish between metastatic and thyroid remnant tissues. Iodine uptake was rated as a metastatic focus if located outside the thyroid bed. Lesion- and patient-based analyses were performed. RESULTS: The study included 137 patients with 227 metastases iodine-positive on both functional imaging modalities. In the lesion-based analysis, (124)I PET and (131)I imaging detected 98% (223/227) and 99% (225/227) of the iodine-positive metastases, respectively; the level of agreement between (124)I PET and (131)I imaging was 97% (221/227). Four metastases (3 lymph node and 1 bone) in 4 patients were (124)I-negative but (131)I-positive, and 2 lymph node metastases in 2 patients were (131)I-negative but (124)I-positive. In the patient-based analysis, 61 of the 137 patients presented with iodine-positive metastases. (124)I PET and (131)I imaging detected at least one iodine-positive metastasis in 97% (59/61) and 98% (60/61) of the patients, respectively. The level of agreement was 95% (58/61). Both imaging modalities concordantly identified 76 of 137 patients without pathologic iodine uptake. CONCLUSION: Because of the high level of agreement, pretherapeutic (124)I PET/CT is an adequate methodology in the detection of iodine-positive metastases and can be used as a reliable tool for staging of thyroid cancer patients and individualized treatment planning.

Use of the bolus tracking technique for the tomographic evaluation of the uretero-vesicular junction in dogs and assessment of dose records.

BACKGROUND: The aim of the work is the application of a bolus tracking technique for tomographic evaluation of the uretero-vesicular junction in dogs. Ten adult dogs (8-14 years) with variable body weight (2,8-32 kg) were enrolled in the prospective study. The patients were placed in sternal recumbency with a 10° elevated pelvis and the visualization of the uretero-vesicular junction was obtained with the bolus tracking technique after intravenous administration of non-ionic contrast medium. In the post-contrast late phase a region of interest was placed within the lumen of the distal ureters and the density values were monitored before starting the helical scan. RESULTS: The uretero-vesicular junction was clearly visible in 100% of patients with the visualization of the endoluminal ureteral contrast enhancement and bladder washout. At the end of the tomographic study an evaluation of the dose records was performed and compared to human exposures reported in literature for the pelvic region. The effective dose estimated for each patient (37,5-138 mSv) proved to be elevated, when compared to those reported in human patients. CONCLUSION: The bolus tracking technique could be applied for the visualization of the uretero-vesicular junction in non-pathological patients, placing the region of interest in the distal ureters. The high effective doses recorded in our study support the need of specific thresholds for veterinary patients, pointing out the attention for paediatric patient's exposure also in veterinary imaging.

Efficacy of radioembolization according to tumor morphology and portal vein thrombosis in intermediate-advanced hepatocellular carcinoma.

PURPOSE: We analyzed overall survival (OS) following radioembolization according to macroscopic growth pattern (nodular vs infiltrative) and vascular invasion in intermediate-advanced hepatocellular carcinoma (HCC). METHODS: Between September 2005 and November 2013, 104 patients (50.0% portal vein thrombosis [PVT], 29.8% infiltrative morphology) were treated. RESULTS: Median OS differed significantly between patients with segmental and lobar or main PVT (p = 0.031), but was 17 months in both those with patent vessels and segmental PVT. Median OS did not differ for infiltrative and nodular HCC. Median OS was prolonged in patients with a treatment response at 3 months (p = 0.023). Prior TACE was also a significant predictor of improved OS. CONCLUSION: A further indication for radioembolization might be infiltrative HCC, since OS was similar to nodular types.

18F-Fluciclovine PET/CT for the Detection of Prostate Cancer Relapse: A Comparison to 11C-Choline PET/CT.

PURPOSE: In recent years, a new PET compound (anti-3-(18)F-FACBC or (18)F-fluciclovine) was tested for the detection of prostate cancer relapse. Despite very promising results, only preliminary data were available with regard to the comparison to (11)C-choline. The aim of this study was to compare the detection rate of (18)F-FACBC and (11)C-choline in patients presenting a biochemical relapse. PATIENTS AND METHODS: Fifty patients radically treated for prostate cancer and presenting with rising prostate-specific antigen (PSA) levels were consecutively and prospectively enrolled. All the patients were out of hormonal therapy and underwent both (11)C-choline PET/CT and (18)F-fluciclovine PET/CT within 1 week. The results were compared in terms of detection rate on a patient and lesion basis. Furthermore, a more detailed analysis regarding local, lymph node, and bone relapse was performed. RESULTS: On a patient-based analysis, (18)F-fluciclovine detection turned out to be significantly superior to (11)C-choline (P < 0.000001). This result was also true on lesion, lymph node, bone lesion, and local relapse analysis (P < 0.0001 in all the cases). There was no significant difference in terms of target to background of positive lesions between (11)C-choline and (18)F-fluciclovine. When the patients were divided into groups with different PSA levels, (18)F-fluciclovine had a superior detection rate for low, intermediate, and high PSA levels. CONCLUSIONS: In our experimental conditions, (18)F-fluciclovine provided a statistically significant better performance in terms of lesion detection rate as compared with (11)C-choline. However, more studies are required to evaluate the clinical significance of these results in terms of sensitivity, specificity, and accuracy.

Radioembolization with Yttrium-90 microspheres in hepatocellular carcinoma: Role and perspectives.

Transarterial radioembolization (TARE) is a form of brachytherapy in which intra-arterially injected yttrium-90-loaded microspheres serve as a source for internal radiation purposes. On the average, it produces disease control rates exceeding 80% and it is a consolidated therapy for hepatocellular carcinoma (HCC); however, current data are all based on retrospective series or non-controlled prospective studies since randomized controlled trials comparing it with the other liver-directed therapies for intermediate and locally advanced stage HCC are still underway. The data available show that TARE provides similar or even better survival rates when compared to transarterial chemoembolization (TACE). First-line TARE is best indicated for both intermediate-stage patients (staged according to the barcelona clinic liver cancer staging classification) who have lesions which respond poorly to TACE due to multiple tumors or a large tumor burden, and for locally advanced-stage patients with solitary tumors, and segmental or lobar portal vein tumor thrombosis. In addition, emerging data have suggested the use of TARE in patients who are classified slightly beyond the Milan criteria regarding radical treatment for downstaging purposes. As a second-line treatment, TARE can also be applied in patients progressing to TACE or sorafenib; a large number of phase II/III trials are ongoing with the purpose of evaluating the best association with systemic therapies. Transarterial radioembolization is very well tolerated and has a low rate of complications which are mainly related to unintended non-target tissue irradiation, including the surrounding liver parenchyma. The complications can be additionally reduced by accurate patient selection and a strict pre-treatment evaluation including dosimetry and assessment of the vascular anatomy. Since a correct treatment algorithm for potential TARE candidates is not clear and standardized, this comprehensive review analyzes the best selection criteria for patients who really benefit from TARE and also the new advances of this therapy, which can be a very important weapon against HCC.

Selective transarterial radioembolisation of unresectable liver-dominant colorectal cancer refractory to chemotherapy.

PURPOSE: The target lesion response (according to the Choi criteria), safety and survival following selective or superselective transarterial radioembolisation using yttrium-90-resin microspheres ((90)Y-RE) were evaluated in patients with unresectable, chemotherapy-refractory colorectal cancer liver metastases (mCRC). MATERIALS AND METHODS: A prospective case series evaluated 52 consecutive patients with mCRC who were treated at a single centre following a median of 2 lines of chemotherapy. RESULTS: Nearly half (46.2 %) of the 52 patients had a prior resection of the liver. At baseline, mCRC was limited to the liver (in 56.9 %), liver plus extra-hepatic metastases (23.5 %) or liver plus lung micro-nodules (19.6 %). Disease control rates of target lesions (partial response plus stable disease) at 3 and 6 months post-(90)Y-RE were 59 and 29 %, respectively. Target lesions were sufficiently downsized in two patients for hepatic resection and in one patient for radiofrequency ablation. Median Kaplan-Meier survival was 11.0 months (95 % confidence interval: 8.0-14.0 months) overall and 12.0 months in liver-only disease (±lung micro-nodules). Determinants of prolonged survival were response at 3 months (P = 0.046), ≤5 liver nodules (P = 0.004), single-liver-lobe involvement (P = 0.037), tumour-to-whole liver ratio <25 % (P = 0.021) and absence of extrahepatic metastases (P = 0.045). Adverse events possibly related to the nontarget distribution of (90)Y-RE were grade 1 (90)Y-RE-induced liver disease (n = 1), grade 2 and 3 gastric ulcers (n = 2). CONCLUSION: These results confirm the effectiveness and safety of selective (90)Y-RE in patients with chemotherapy-refractory mCRC, showing (90)Y-RE's potential as a bridging therapy to subsequent resection even in this end-stage population.

Yttrium-90 radioembolization vs sorafenib for intermediate-locally advanced hepatocellular carcinoma: a cohort study with propensity score analysis.

BACKGROUND & AIMS: Sorafenib and transarterial (90) Y-radioembolization (TARE) are possible treatments for Barcelona Clinic Liver Cancer (BCLC) intermediate-advanced stage hepatocellular carcinoma (HCC). No study directly comparing sorafenib and TARE is currently available. This single-centre retrospective study compares the outcomes achieved with sorafenib and TARE in HCC patients potentially amenable to either therapy. METHODS: Seventy-four sorafenib (71 ± 10 years, male 87%, BCLC B/C 53%/47%) and 63 TARE HCC patients (66 ± 9 years, male 79%, BCLC B/C 41%/59%) were included based on the following criteria: Child-Pugh class A/B, performance status ≤1, HCC unfit for other effective therapies, no metastases and no previous systemic chemotherapy. RESULTS: Median overall survivals of the two groups were comparable, being 14.4 months (95% CI: 4.3-24.5) in sorafenib and 13.2 months (95% CI: 6.1-20.2) in TARE patients, with 1-, 2- and 3-year survival rates of 52.1%, 29.3% and 14.7% vs 51.8%, 27.8% and 21.6% respectively. Two TARE patients underwent liver transplantation after successful down-staging. To minimize the impact of confounding factors on survival analysis, propensity model matched 32 patients of each group for median age, tumour gross pathology and the independent prognostic factors (portal vein thrombosis, performance status, Model for End Liver Disease). Even after matching, the median survival did not differ between sorafenib (13.1 months; 95% CI: 1.2-25.9) and TARE patients (11.2 months; 95% CI: 6.7-15.7), with comparable 1-, 2- and 3-year survival rates. CONCLUSIONS: In cirrhotic patients with intermediate-advanced or not-otherwise-treatable HCC, sorafenib and TARE provide similar survivals. Down-staging allowing liver transplantation only occurred after TARE.

11C-mHED for PET / CT: principles of synthesis, methodology and first clinical applications.

Alterations of the cardiac autonomic nervous system play an important role in the pathway of many heart diseases. Nuclear imaging tools have been demonstrated to be useful for global and regional assessment of myocardial innervation. We used (11)C-meta-hydroxy-ephedrine ((11)C-mHED), a catecholamine analogue, as a radiotracer usable with a PET/CT scanner to study the cardiac sympathetic system. After a fast and automatic synthesis of mHED and its labeling with (11)C, we acquired cardiac images by using a PET/ CT scanner. In this paper we present our preliminary results showing the radiotracer bio-distribution in humans 10 minutes post injection. The present study assesses the feasibility of PET/CT with the radiolabeled catecholamine analogue ((11)C-mHED) in order to determine sympathetic innervation in the human heart.

Pretherapeutic dosimetry in patients affected by metastatic thyroid cancer using 124I PET/CT sequential scans for 131I treatment planning.

PURPOSE: This study evaluates the use of sequential I PET/CT for predicting absorbed doses to metastatic lesions in patients with differentiated thyroid cancer undergoing I therapy. METHODS: From July 2011 until July 2013, 30 patients with metastatic differentiated thyroid cancer were enrolled. Each participant underwent PET/CT at 4, 24, 48, and 72 hours with 74 MBq of I. Blood samples and whole-body exposure measurements were obtained to calculate blood and red marrow doses. Activity concentrations and lesion volumes obtained from PET/CT were used to evaluate tumor doses with medical internal radiation dose formalism and spheres modeling. Mean administered I therapeutic dose was 5994 MBq (range, 1953-11,455 MBq). RESULTS: I PET/CT demonstrated all lesions detected by posttherapy I whole-body scans. Mean dose rates for blood, red marrow, and lesions were as follows: 0.07 ± 0.02 mGy/MBq, 0.05 ± 0.02 mGy/MBq, and 46.5 ± 117 mGy/MBq, respectively. Despite the high level of thyroid-stimulating hormone and CT detectable lesions, 15 of 30 patients did not show any abnormal I uptake. CONCLUSIONS: The quantitative value of I PET/CT allows simple and accurate evaluation of lesion dosimetry following medical internal radiation dose formalism. Negative I PET/CT predicts absence of iodine avidity, potentially allowing avoidance of therapeutically ineffective I administration.