Prospective Multicentric Assessment of 68Ga-DOTANOC PET/CT in Grade 1-2 GEP-NET.

The aim of this multicentric study was to prospectively compare 68Ga-DOTANOC PET/CT versus somatostatin receptor scintigraphy (SRS) with SPECT/CT, combined with multiphasic CT scan and MRI in patients with grade 1 or 2 gastroenteropancreatic neuroendocrine tumors (GEP-NET). Patients with histologically proven grade 1 or 2 GEP-NET with suspicion of recurrence or progression, or with typical aspects of GEP-NET on morphological imaging, were explored with conventional imaging (CI): SRS with SPECT/CT, multiphasic CT scan and/or liver MRI followed by 68Ga-DOTANOC PET/CT. The gold standard was based on histology and imaging follow-up. The data of 105 patients (45 woman and 60 men; median age) were analyzed. 68Ga-DOTANOC PET/CT sensitivity was significantly higher than CI sensitivity in per-patient (98.9% vs. 88.6%, p = 0.016) and per-region (97.6% vs. 75.6%, p < 0.001) analyses, in the detection of the primary (97.9% vs. 78.7%; p = 0.016), peritoneal carcinomatosis (95% vs. 30%, p < 0.001), and bone metastases (100% vs. 33.3%, p = 0.041). 68Ga-DOTANOC PET/CT had an impact on the therapeutic management of 41.9% (44/105) patients compared to decisions based on CI explorations. Our data confirm the superiority of 68Ga-DOTANOC PET/CT over CI in the detection of peritoneal carcinomatosis and bone metastasis, as well as its strong therapeutic impact on the management of patients with grade 1-2 GEP-NETs.

Anti-CEA Pretargeted Immuno-PET Shows Higher Sensitivity Than DOPA PET/CT in Detecting Relapsing Metastatic Medullary Thyroid Carcinoma: Post Hoc Analysis of the iPET-MTC Study.

Pretargeting parameters for the use of anti-carcinoembryonic antigen (CEA) bispecific monoclonal antibody TF2 and the 68Ga-labeled IMP288 peptide for immuno-PET have been optimized in a first-in-humans study performed on medullary thyroid carcinoma (MTC) patients (the iPET-MTC study). The aim of this post hoc analysis was to determine the sensitivity of immuno-PET in relapsing MTC patients, in comparison with conventional imaging and 18F-l-dihydroxyphenylalanine (18F-DOPA) PET/CT. Methods: Twenty-five studies were analyzed in 22 patients. All patients underwent immuno-PET 1 and 2 h after 68Ga-IMP288 injection pretargeted by TF2, in addition to neck, thoracic, abdominal, and pelvic CT; bone and liver MRI; and 18F-DOPA PET/CT. The gold standard was histology or confirmation by one other imaging method or by imaging follow-up. Results: In total, 190 lesions were confirmed by the gold standard: 89 in lymph nodes, 14 in lungs, 46 in liver, 37 in bone, and 4 in other sites (subcutaneous tissue, heart, brain, and pancreas). The number of abnormal foci detected by immuno-PET was 210. Among these, 174 (83%) were confirmed as true-positive by the gold standard. Immuno-PET showed a higher overall sensitivity (92%) than 18F-DOPA PET/CT (65%). Regarding metastatic sites, immuno-PET had a higher sensitivity than CT, 18F-DOPA PET/CT, or MRI for lymph nodes (98% vs. 83% for CT and 70% for 18F-DOPA PET/CT), liver (98% vs. 87% for CT, 65% for 18F-DOPA PET/CT, and 89% for MRI), and bone (92% vs. 64% for 18F-DOPA PET/CT and 86% for MRI), whereas sensitivity was lower for lung metastases (29% vs. 100% for CT and 14% for 18F-DOPA PET/CT). Tumor SUVmax at 60 min ranged from 1.2 to 59.0, with intra- and interpatient variability. Conclusion: This post hoc study demonstrates that anti-carcinoembryonic antigen immuno-PET is an effective procedure for detecting metastatic MTC lesions. Immuno-PET showed a higher overall sensitivity than 18F-DOPA PET/CT for disclosing metastases, except for the lung, where CT remains the most effective examination.

Assessment of Inflammation and Calcification in Pseudoxanthoma Elasticum Arteries and Skin with 18F-FluroDeoxyGlucose and 18F-Sodium Fluoride Positron Emission Tomography/Computed Tomography Imaging: The GOCAPXE Trial.

BACKGROUND: Pseudoxanthoma elasticum (PXE) is an inherited metabolic disease characterized by elastic fiber fragmentation and ectopic calcification. There is growing evidence that vascular calcification is associated with inflammatory status and is enhanced by inflammatory cytokines. Since PXE has never been considered as an inflammatory condition, no incidence of chronic inflammation leading to calcification in PXE has been reported and should be investigated. In atherosclerosis and aortic stenosis, positron emission tomography combined with computed tomographic (PET-CT) imaging has demonstrated a correlation between inflammation and calcification. The purpose of this study was to assess skin/artery inflammation and calcification in PXE patients. Methods: 18F-FluroDeoxyGlucose (18F-FDG) and 18F-Sodium Fluoride (18F-NaF) PET-CT, CT-imaging and Pulse wave velocity (PWV) were used to determine skin/vascular inflammation, tissue calcification, arterial calcium score (CS) and stiffness, respectively. In addition, inorganic pyrophosphate, high-sensitive C-reactive protein and cytokines plasma levels were monitored. RESULTS: In 23 PXE patients, assessment of inflammation revealed significant 18F-FDG uptake in diseased skin areas contrary to normal regions, and exclusively in the proximal aorta contrary to the popliteal arteries. There was no correlation between 18F-FDG uptake and PWV in the aortic wall. Assessment of calcification demonstrated significant 18F-NaF uptake in diseased skin regions and in the proximal aorta and femoral arteries. 18F-NaF wall uptake correlated with CS in the femoral arteries, and aortic wall PWV. Multivariate analysis indicated that aortic wall 18F-NaF uptake is associated with diastolic blood pressure. There was no significant correlation between 18F-FDG and 18F-NaF uptake in any of the artery walls. CONCLUSION: In the present cross-sectional study, inflammation and calcification were not correlated. PXE would appear to more closely resemble a chronic disease model of ectopic calcification than an inflammatory condition. To assess early ectopic calcification in PXE patients, 18F-NaF-PET-CT may be more relevant than CT imaging. It potentially constitutes a biomarker for disease-modifying anti-calcifying drug assessment in PXE.

Dual time point [18F]FLT-PET for differentiating proliferating tissues vs non-proliferating tissues.

PURPOSE: For differentiating tumor from inflammation and normal tissues, fluorodeoxyglucose ([18F]FDG) dual time point PET could be helpful. Albeit [18F]FLT is more specific for tumors than [18F]FDG; we explored the role of dual time point [18F]FLT-PET for discriminating benign from malignant tissues. METHODS: Before any treatment, 85 womens with de novo unifocal breast cancer underwent three PET acquisitions at 33.94 ± 8.01 min (PET30), 61.45 ± 8.30 min (PET60), and 81.06 ± 12.12 min (PET80) after [18F]FLT injection. Semiquantitative analyses of [18F]FLT uptake (SUV) were carried out on tumors, liver, bone marrow (4th thoracic vertebra (T4) and humeral head), descending thoracic aorta, muscle (deltoid), and contralateral normal breast. Repeated measures ANOVA tests and Tukey's posttests were used to compare SUVmax of each site at the three time points. RESULTS: There was a significant increase in SUVmax over time for breast lesions (5.58 ± 3.80; 5.97 ± 4.56; 6.19 ± 4.42; p < 0.0001) (m ± SD for PET30, PET60, and PET80, respectively), and bone marrow (for T4, 8.21 ± 3.17, 9.64 ± 3.66, 10.85 ± 3.63, p < 0.0001; for humeral head, 3.36 ± 1.79, 3.87 ± 1.89, 4.39 ± 2.00, p < 0.0001). A significant decrease in SUVmax over time was observed for liver (6.79 ± 2.03; 6.24 ± 1.99; 5.57 ± 1.74; p < 0.0001), muscle (0.95 ± 0.28; 0.93 ± 0.29; 0.86 ± 0.20; p < 0.027), and aorta (1.18 ± 0.34; 1.01 ± 0.32; 0.97 ± 0.30; p < 0.0001). No significant difference was observed for SUVmax in contralateral breast (0.8364 ± 0.40; 0.78 ± 0.38; 0.80 ± 0.35). CONCLUSION: [18F]FLT-SUVmax increased between 30 and 80 min only in proliferating tissues. This could be helpful for discriminating between residual tumor and scar tissue.

Bendamustine and rituximab in elderly patients with low-tumour burden follicular lymphoma. Results of the LYSA phase II BRIEF study.

The treatment of low-tumour burden follicular lymphoma (LTBFL) remains a challenge. Rituximab-based strategies may be improved by adding chemotherapy. This Lymphoma Study Association multicentre phase II study assessed rituximab and bendamustine in 63 patients with untreated LTBFL who were aged over 60 years old and had a follicular lymphoma International Prognostic Index (FLIPI) score ≥2. Induction comprised 4 weekly cycles of rituximab 375 mg/m2 intravenously combined with 2 cycles of bendamustine 90 mg/m2 days 1-2 with a 28-day interval, followed by twelve cycles of 375 mg/m2 rituximab maintenance therapy every 8 weeks. The primary endpoint was complete response (CR)/unconfirmed CR (CRu), at 12 weeks. Median age was 67·4 years and median FLIPI was 3. Ultimately, 18 patients (29%) had high tumour burden according to Groupe d'Etude des Lymphomes Folliculaires criteria. The 12-week CR/CRu rate was 54·0% and the overall response rate was 93·7%. Surprisingly, 3 patients died during maintenance (2 sepsis, 1 neoplasm). Progression-free survival was 85·4% at 24 months. In LTBFL patients with FLIPI ≥2, two cycles of rituximab and bendamustine result in a CR rate of 54·0%. However, the treatment-related deaths observed do not allow this regimen to be recommended for LTBFL patients aged over 60 years. EudraCT: 2010-020757-14; ClinicalTrials.gov: NCT01313611.

Efficacy and safety of selective internal radiotherapy with yttrium-90 resin microspheres compared with sorafenib in locally advanced and inoperable hepatocellular carcinoma (SARAH): an open-label randomised controlled phase 3 trial.

BACKGROUND: Sorafenib is the recommended treatment for patients with advanced hepatocellular carcinoma. We aimed to compare the efficacy and safety of sorafenib to that of selective internal radiotherapy (SIRT) with yttrium-90 (90Y) resin microspheres in patients with hepatocellular carcinoma. METHODS: SARAH was a multicentre, open-label, randomised, controlled, investigator-initiated, phase 3 trial done at 25 centres specialising in liver diseases in France. Patients were eligible if they were aged at least 18 years with a life expectancy greater than 3 months, had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, Child-Pugh liver function class A or B score of 7 or lower, and locally advanced hepatocellular carcinoma (Barcelona Clinic Liver Cancer [BCLC] stage C), or new hepatocellular carcinoma not eligible for surgical resection, liver transplantation, or thermal ablation after a previously cured hepatocellular carcinoma (cured by surgery or thermoablative therapy), or hepatocellular carcinoma with two unsuccessful rounds of transarterial chemoembolisation. Patients were randomly assigned (1:1) by a permutated block method with block sizes two and four to receive continuous oral sorafenib (400 mg twice daily) or SIRT with 90Y-loaded resin microspheres 2-5 weeks after randomisation. Patients were stratified according to randomising centre, ECOG performance status, previous transarterial chemoembolisation, and presence of macroscopic vascular invasion. The primary endpoint was overall survival. Analyses were done on the intention-to-treat population; safety was assessed in all patients who received at least one dose of sorafenib or underwent at least one of the SIRT work-up exams. This study has been completed and the final results are reported here. The trial is registered with ClinicalTrials.gov, number NCT01482442. FINDINGS: Between Dec 5, 2011, and March 12, 2015, 467 patients were randomly assigned; after eight patients withdrew consent, 237 were assigned to SIRT and 222 to sorafenib. In the SIRT group, 53 (22%) of 237 patients did not receive SIRT; 26 (49%) of these 53 patients were treated with sorafenib. Median follow-up was 27·9 months (IQR 21·9-33·6) in the SIRT group and 28·1 months (20·0-35·3) in the sorafenib group. Median overall survival was 8·0 months (95% CI 6·7-9·9) in the SIRT group versus 9·9 months (8·7-11·4) in the sorafenib group (hazard ratio 1·15 [95% CI 0·94-1·41] for SIRT vs sorafenib; p=0·18). In the safety population, at least one serious adverse event was reported in 174 (77%) of 226 patients in the SIRT group and in 176 (82%) of 216 in the sorafenib group. The most frequent grade 3 or worse treatment-related adverse events were fatigue (20 [9%] vs 41 [19%]), liver dysfunction (25 [11%] vs 27 [13%]), increased laboratory liver values (20 [9%] vs 16 [7%]), haematological abnormalities (23 [10%] vs 30 [14%]), diarrhoea (three [1%] vs 30 [14%]), abdominal pain (six [3%] vs 14 [6%]), increased creatinine (four [2%] vs 12 [6%]), and hand-foot skin reaction (one [<1%] vs 12 [6%]). 19 deaths in the SIRT group and 12 in the sorafenib group were deemed to be treatment related. INTERPRETATION: In patients with locally advanced or intermediate-stage hepatocellular carcinoma after unsuccessful transarterial chemoembolisation, overall survival did not significantly differ between the two groups. Quality of life and tolerance might help when choosing between the two treatments. FUNDING: Sirtex Medical Inc.

Characterization of the distribution, retention, and efficacy of internal radiation of 188Re-lipid nanocapsules in an immunocompromised human glioblastoma model.

Internal radiation strategies hold great promise for glioblastoma (GB) therapy. We previously developed a nanovectorized radiotherapy that consists of lipid nanocapsules loaded with a lipophilic complex of Rhenium-188 (LNC188Re-SSS). This approach resulted in an 83 % cure rate in the 9L rat glioma model, showing great promise. The efficacy of LNC188Re-SSS treatment was optimized through the induction of a T-cell immune response in this model, as it is highly immunogenic. However, this is not representative of the human situation where T-cell suppression is usually encountered in GB patients. Thus, in this study, we investigated the efficacy of LNC188Re-SSS in a human GB model implanted in T-cell deficient nude mice. We also analyzed the distribution and tissue retention of LNC188Re-SSS. We observed that intratumoral infusion of LNCs by CED led to their complete distribution throughout the tumor and peritumoral space without leakage into the contralateral hemisphere except when large volumes were used. Seventy percent of the 188Re-SSS activity was present in the tumor region 24 h after LNC188Re-SSS injection and no toxicity was observed in the healthy brain. Double fractionated internal radiotherapy with LNC188Re-SSS triggered survival responses in the immunocompromised human GB model with a cure rate of 50 %, which was not observed with external radiotherapy. In conclusion, LNC188Re-SSS can induce long-term survival in an immunosuppressive environment, highlighting its potential for GB therapy.

68Ga and 188Re Starch-Based Microparticles as Theranostic Tool for the Hepatocellular Carcinoma: Radiolabeling and Preliminary In Vivo Rat Studies.

PURPOSE: This work aims to develop, validate and optimize the radiolabeling of Starch-Based Microparticles (SBMP) by 188Re and 68Ga in the form of ready-to-use radiolabeling kits, the ultimate goal being to obtain a unique theranostic vector for the treatment of Hepatocellular Carcinoma. METHODS: Optimal labeling conditions and composition of freeze-dried kits were defined by monitoring the radiochemical purity while varying several parameters. In vitro stability studies were carried out, as well as an in vivo biodistribution as a preliminary approach with the intra-arterial injection of 68Ga radiolabeled SBMP into the hepatic artery of DENA-induced rats followed by PET/CT imaging. RESULTS: Kits were optimized for 188Re and 68Ga with high and stable radiochemical purity (>95% and >98% respectively). The in vivo preliminary study was successful with more than 95% of activity found in the liver and mostly in the tumorous part. CONCLUSION: SBMP are a promising theranostic agent for the Selective Internal Radiation Therapy of Hepatocellular carcinoma.

Immuno-PET Using Anticarcinoembryonic Antigen Bispecific Antibody and 68Ga-Labeled Peptide in Metastatic Medullary Thyroid Carcinoma: Clinical Optimization of the Pretargeting Parameters in a First-in-Human Trial.

Earlier clinical studies reported a high sensitivity of pretargeted immunoscintigraphy using murine or chimeric anticarcinoembryonic antigen (CEA) bispecific antibody (BsMAb) and peptides labeled with 111In or 131I in medullary thyroid carcinoma (MTC). Preclinical studies showed that new-generation humanized recombinant anti-CEA × antihistamine-succinyl-glycine (HSG) trivalent BsMAb TF2 and radiolabeled HSG peptide (IMP288) present good features for PET. This study aimed at optimizing molar doses and pretargeting interval of TF2 and 68Ga-labeled IMP288 for immuno-PET in relapsed MTC patients with calcitonin serum levels greater than 150 pg/mL. METHODS: Five cohorts (C1-C5) of 3 patients received variable molar doses of TF2 and approximately 150 MBq of 68Ga-IMP288 after different pretargeting time intervals (C1: 120 nmol TF2, 6 nmol IMP288, 24 h; C2: 120 nmol TF2, 6 nmol IMP288, 30 h; C3: 120 nmol TF2, 6 nmol IMP288, 42 h; C4: 120 nmol TF2, 3 nmol IMP288, 30 h; and C5: 60 nmol TF2, 3 nmol IMP288, 30 h). TF2 and 68Ga-IMP288 pharmacokinetics were monitored. Whole-body PET was recorded 60 and 120 min after 68Ga-IMP288 injection. Tumor maximal SUV (T-SUVmax) and T-SUVmax-to-mediastinum blood-pool (MBP) SUVmean ratios (T/MBP) were determined. RESULTS: In C1, T-SUVmax and T/MBP ranged from 4.09 to 8.93 and 1.39 to 3.72 at 60 min and 5.14 to 11.25 and 2.73 to 5.38 at 120 min, respectively. Because of the high MBP, the delay was increased to 30 h in C2, increasing T-SUVmax and T/MBP. Further increasing the delay to 42 h in C3 decreased T-SUVmax and T/MBP, showing that 30 h was the most favorable delay. In C4, the TF2-to-peptide mole ratio was increased to 40 (delay 30 h), resulting in high T-SUVmax but with higher MBP than in C2. In C5, the molar dose of TF2 was reduced, resulting in lower imaging performance. Pharmacokinetics demonstrated a fast TF2 clearance and a clear relationship between blood activity clearance and the ratio between the molar amount of injected peptide to the molar amount of circulating TF2 at the time of peptide injection. CONCLUSION: High tumor uptake and contrast can be obtained with pretargeted anti-CEA immuno-PET in relapsed MTC patients, especially using optimized pretargeting parameters: a BsMAb-to-peptide mole ratio of 20 and 30 h pretargeting delay.

For avid glucose tumors, the SUV peak is the most reliable parameter for [(18)F]FDG-PET/CT quantification, regardless of acquisition time.

BACKGROUND: This study is an assessment of the impact of acquisition times on SUV with [(18)F]FDG-PET/CT on healthy livers (reference organ with stable uptake over time) and on tumors. METHODS: One hundred six [(18)F]FDG-PET/CT were acquired in list mode over a single-bed position (livers (n = 48) or on tumors (n = 58)). Six independent datasets of different durations were reconstructed (from 1.5 to 10 min). SUVmax (hottest voxel), SUVpeak (maximum average SUV within a 1-cm(3) spherical volume), and SUVaverage were measured within a 3-cm-diameter volume of interest (VOI) in the right lobe of the liver. For [(18)F]FDG avid tumors (SUVmax ≥ 5), the SUVmax, SUVpeak, and SUV41% (isocontour threshold method) were computed. RESULTS: For tumors, SUVpeak values did not vary with acquisition time. SUVmax displayed significant differences between 1.5- and 5-10-min reconstruction times. SUV41% was the most time-dependent parameter. For the liver, the SUVaverage was the sole parameter that did not vary over time. CONCLUSIONS: For [(18)F]FDG avid tumors, with short acquisition times, i.e., with new generations of PET systems, the SUVpeak may be more robust than the SUVmax. The SUVaverage over a 3-cm-diameter VOI in the right lobe of the liver appears to be a good method for a robust and reproducible assessment of the hepatic metabolism.

Limited screening with versus without (18)F-fluorodeoxyglucose PET/CT for occult malignancy in unprovoked venous thromboembolism: an open-label randomised controlled trial.

BACKGROUND: Clear guidelines for the investigation of occult malignancy after unprovoked venous thromboembolism are not yet available. (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT could serve as a comprehensive screening strategy for occult malignancy in this context. We aimed to compare a screening strategy based on (18)F-FDG PET/CT with a limited screening strategy for detection of malignant disease in patients with unprovoked venous thromboembolism. METHODS: In an open-label, multicentre, randomised study we enrolled patients from four French university hospitals. Patients aged 18 years or older, diagnosed with unprovoked venous thromboembolism (not provoked by a major inherited or acquired risk factor) were invited to participate. Patients were randomly assigned in a 1:1 ratio to a limited screening strategy (physical examination, usual laboratory tests, and basic radiographs) or a screening strategy consisting of the limited strategy plus an (18)F-FDG PET/CT scan. Randomisation was done with a dedicated central web-based randomisation system, in block sizes of six, stratified by centre, and concealed from the investigators. Patients and investigators were not masked to study group assignment. Patients were followed up for 2 years. The primary outcome was the proportion of patients with a cancer diagnosis in each group after the initial screening assessment. Analyses were conducted in modified intention-to-test and per-protocol populations. This trial is completed and registered with ClinicalTrials.gov, number NCT00964275. FINDINGS: Between March 3, 2009, and Aug 18, 2012, we enrolled and randomly assigned 399 patients; five withdrew consent, leaving 197 in each group for the modified intention-to-test analysis. After initial screening assessment, cancer was diagnosed in 11 (5·6%) patients in the (18)F-FDG PET/CT group and four (2·0%) patients in the limited screening group (absolute risk difference 3·6%, 95% CI -0·4 to 7·9; p=0·07). At the initial screening assessment, seven (64%) of the 11 cancers diagnosed in the (18)F-FDG PET/CT group were early-stage compared with two of four cancers diagnosed in the limited screening group (p=1·00). One (0·5%) occult malignancy was detected in 186 patients who had negative initial screening in the (18)F-FDG PET/CT group, compared with nine (4·7%) in 193 patients in the limited screening group (absolute risk difference 4·1%, 95% CI 0·8 to 8·4, p=0·01). Overall, five (42%) of the 12 cancers diagnosed in the (18)F-FDG PET/CT group were advanced stage, compared with seven (54%) of the 13 cancers diagnosed in the limited screening group (p=0·70). 16 patients died during follow-up, eight (4·1%) in each group. Two (1·0%) patients in the (18)F-FDG PET/CT group and five (2·5%) in the limited screening group had cancer-related deaths. INTERPRETATION: A strategy including limited screening and a (18)F-FDG PET/CT was not associated with a significantly higher rate of cancer diagnosis after unprovoked venous thromboembolism. The risk of subsequent cancer diagnosis was, however, lower in patients who had negative initial screening that included (18)F-FDG PET/CT than in patients who had negative initial limited screening. Whether or not (18)F-FDG PET/CT might be useful in a more selected population of patients with a high risk of cancer remains to be determined. FUNDING: Programme Hospitalier de Recherche Clinique (French Department of Health).

Isotopic Scintigraphy Coupled With Computed Tomography for the Investigation of Intrathecal Baclofen Device Malfunction.

OBJECTIVE: To assess the potential use of indium-111 diethylenetriamine pentaacetic acid ((111)In-DTPA) scintigraphy coupled with computed tomography (CT) for the investigation of intrathecal baclofen (ITB) device malfunction. DESIGN: Retrospective study of a case series of patients. SETTING: Neurosurgical and physical and rehabilitation medicine departments. PARTICIPANTS: Patients (N=7) with reduced ITB effectiveness in whom prior conventional radiographs were inconclusive. INTERVENTION: Nine (111)In-DTPA scintigraphic studies and 8 CT scans. Planar acquisitions were followed by tomoscintigraphy combined with CT. MAIN OUTCOME MEASURE: Progression of the radiotracer in the pump, catheters, and in the subarachnoid space. RESULTS: In 7 cases, scintigraphy coupled with CT showed leakage behind the pump, lack of activity outside the pump reservoir, abrupt interruption of activity in the catheter, or abnormal distribution of the radiotracer, thus demonstrating that the drug did not reach its target. Surgical revision confirmed these findings in 5 cases. In 1 case, combined imagery ruled out device dysfunction. In the remaining case, only planar acquisitions were performed, showing correct diffusion of the radiotracer. CONCLUSIONS: The combination of scintigraphy and CT provides simultaneous functional and anatomic imagery of the device. The slow infusion of the radioisotope mimics the diffusion of baclofen, and this could be a useful method to explore intrathecal device malfunction. Further studies are required to compare scintigraphy coupled with CT, to radiopaque injection followed by fluoroscopy or CT.

Pharmacokinetics and Dosimetry Studies for Optimization of Pretargeted Radioimmunotherapy in CEA-Expressing Advanced Lung Cancer Patients.

OBJECTIVES: A phase I pretargeted radioimmunotherapy trial (EudractCT 200800603096) was designed in patients with metastatic lung cancer expressing carcinoembryonic antigen (CEA) to optimize bispecific antibody and labeled peptide doses, as well as the delay between their injections. METHODS: Three cohorts of three patients received the anti-CEA × anti-histamine-succinyl-glycine (HSG)-humanized trivalent bispecific antibody (TF2) and the IMP288 bivalent HSG peptide. Patients underwent a pretherapeutic imaging session S1 (44 or 88 nmol/m(2) of TF2 followed by 4.4 nmol/m(2), 185 MBq, of (111)In-labeled IMP288) and, 1-2 weeks later, a therapy session S2 (240 or 480 nmol/m(2) of TF2 followed by 24 nmol/m(2), 1.1 GBq/m(2), of (177)Lu-labeled IMP288). The pretargeting delay was 24 or 48 h. The dose schedule was defined based on preclinical TF2 pharmacokinetic (PK) studies, on our previous clinical data using the previous anti-CEA-pretargeting system, and on clinical results observed in the first patients injected using the same system in Netherlands. RESULTS: TF2 PK was represented by a two-compartment model in which the central compartment volume (Vc) was linearly dependent on the patient's surface area. PK was remarkably similar, with a clearance of 0.33 ± 0.03 L/h/m(2). (111)In- and (177)Lu-IMP288 PK was also well represented by a two-compartment model. IMP288 PK was faster (clearance 1.4-3.3 L/h). The Vc was proportional to body surface area, and IMP288 clearance depended on the molar ratio of injected IMP288 to circulating TF2 at the time of IMP288 injection. Modeling of image quantification confirmed the dependence of IMP288 kinetics on circulating TF2, but tumor activity PK was variable. Organ-absorbed doses were not significantly different in the three cohorts, but the tumor dose was significantly higher with the higher molar doses of TF2 (p < 0.002). S1 imaging predicted absorbed doses calculated in S2. CONCLUSION: The best dosing parameters corresponded to the shorter pretargeting delay and to the highest TF2 molar doses. S1 imaging session accurately predicted PK as well as absorbed doses of S2, thus potentially allowing for patient selection and dose optimization. TRIAL REGISTRATION: ClinicalTrials.gov NCT01221675 (EudractCT 200800603096).

Isotopic scintigraphy combined with computed tomography: a useful method for investigating inefficiency of intrathecal baclofen.

BACKGROUND: Intrathecal baclofen infusion is an established method for the treatment of generalized and disabling spasticity. The most frequent technical problems are due to catheter /pump disconnections, but diagnosis of dysfunction may be difficult. CASE REPORT: We report here the case of a 53-year-old woman with spastic paraplegia treated with intrathecal baclofen. Spasticity remained uncontrolled despite a gradual increase in baclofen dosage. On plain radiographs the distal end of the catheter was found to be pointing downwards with the catheter tip at level L5 and no apparent disconnection or failure. Indium111 diethylenetriamine penta-acetic acid (DTPA) scintigraphy combined with computed tomography revealed that the activity of the radioisotope was highest next to the first sacral vertebra and that there was no leakage. Radioisotope activity above the lumbar level was very low. The catheter tip was therefore repositioned to level T7. One month later, spasticity was well controlled and a second scintigraphy confirmed high activity of intrathecal radioisotope up to the basal cisterns. DISCUSSION: The combination of Indium111 DTPA scinti-graphy with computed tomography allows anatomical and functional investigation of intrathecal drug administration. In this case report this approach showed that the inefficiency of intrathecal baclofen was due to the caudal orientation of the catheter.

[¹8F]FDG positron emission tomography within two weeks of starting erlotinib therapy can predict response in non-small cell lung cancer patients.

PURPOSE: The aim of this prospective study was to evaluate whether [¹8F]FDG-PET/CT, performed within two weeks of starting erlotinib therapy can predict tumor response defined by RECIST 1.1 criteria after 8 weeks of treatment in patients with inoperable (stage IIIA to IV) non-small cell lung cancer patients. PATIENTS AND METHODS: Three [¹8F]FDG-PET/CT scans were acquired in 12 patients before (5±4 days) and after 9±3 days (early PET) and 60±6 days (late PET) of erlotinib therapy. Conventional evaluation, including at least chest CT (baseline versus after 8 weeks of treatment), was performed according to RECIST 1.1 criteria. Change in [¹8F]FDG uptake was compared with conventional response, progression-free survival (PFS), and overall survival (OS). RESULTS: By using ROC analysis, the Area Under the Curve for prediction of metabolic non-progressive disease (mNP) by early PET was 0.86 (95% CI, 0.62 to 1.1; P = 0.04) at a cut-off of 21.6% reduction in maximum Standardized Uptake Value (SUVmax). This correctly classified 11/12 patients (7 with true progressive disease; 4 with true non-progressive disease; 1 with false progressive disease). Non-progressive disease after 8 weeks of treatment according to RECIST 1.1 criteria was significantly more frequent in patients classified mNP (P = 0.01, Fisher's exact test). mNP patients showed prolonged PFS (HR = 0.27; 95% CI, 0.04 to 0.59; P<0.01) and OS (HR = 0.34; 95% CI, 0.06 to 0.84; P = 0.03). Late PET analysis provided concordant results. CONCLUSION: Morphologic response, PFS and OS survival in non-small cell lung cancer patients can be predicted by [¹8F]FDG-PET/CT scan within 2 weeks after starting erlotinib therapy.

The impact of (18)F-FDG-PET/CT on Merkel cell carcinoma management: a retrospective study of 66 scans from a single institution.

PURPOSE: Merkel cell carcinomas (MCC) are neuroendocrine skin tumours frequently responsible for lymph node recurrence and metastatic disease and for which optimal management remains to be defined. The objective of this study was to evaluate the impact of (18)F-fluorodeoxyglucose ((18)F-FDG)-PET/computed tomography (CT) on the staging and treatment of MCC patients. MATERIALS AND METHODS: Twenty-three patients with a histologic diagnosis of MCC explored by (18)F-FDG-PET/CT between 2004 and 2012 were retrospectively included in the study. The detection of new lesions and the change in tumour staging and treatment were evaluated. For each patient, the (18)F-FDG-PET/CT results were compared with histological, clinical and imaging data. RESULTS: Sixty-six (18)F-FDG-PET/CT scans were performed at initial presentation (n=18), during subsequent monitoring (n=34) or during evaluation of chemotherapy response (n=14). The sensitivity, specificity and positive and negative predictive values of the (18)F-FDG-PET/CT were 97, 89, 94 and 94%, respectively. Two false-positive results (lymphadenitis) and one false-negative result (regional metastatic lymph nodes) were accounted for. Lesions not detected clinically or by conventional imaging techniques were found in 44% of the 52 (18)F-FDG-PET/CTs performed at initial presentation and subsequent monitoring, with, respectively, 50 and 41% of scans identifying new lesions. At initial presentation, (18)F-FDG-PET/CT led to a change in tumour staging in 39% of patients. Patient management was modified by (18)F-FDG-PET/CT results in one-third of patients (33% of patients at initial presentation, 32% during subsequent monitoring and 36% during evaluation of chemotherapy response). F-FDG-PET/CT incidentally detected four additional histologically confirmed cancers. CONCLUSION: This retrospective study confirms the important impact of (18)F-FDG-PET/CT on the management of MCC patients.

Calibration test of PET scanners in a multi-centre clinical trial on breast cancer therapy monitoring using 18F-FLT.

UNLABELLED: A multi-centre trial using PET requires the analysis of images acquired on different systems We designed a multi-centre trial to estimate the value of 18F-FLT-PET to predict response to neoadjuvant chemotherapy in patients with newly diagnosed breast cancer. A calibration check of each PET-CT and of its peripheral devices was performed to evaluate the reliability of the results. MATERIAL AND METHODS: 11 centres were investigated. Dose calibrators were assessed by repeated measurements of a 68Ge certified source. The differences between the clocks associated with the dose calibrators and inherent to the PET systems were registered. The calibration of PET-CT was assessed with an homogeneous cylindrical phantom by comparing the activities per unit of volume calculated from the dose calibrator measurements with that measured on 15 Regions of Interest (ROIs) drawn on 15 consecutive slices of reconstructed filtered back-projection (FBP) images. Both repeatability of activity concentration based upon the 15 ROIs (ANOVA-test) and its accuracy were evaluated. RESULTS: There was no significant difference for dose calibrator measurements (median of difference -0.04%; min = -4.65%; max = +5.63%). Mismatches between the clocks were less than 2 min in all sites and thus did not require any correction, regarding the half life of 18F. For all the PET systems, ANOVA revealed no significant difference between the activity concentrations estimated from the 15 ROIs (median of difference -0.69%; min = -9.97%; max = +9.60%). CONCLUSION: No major difference between the 11 centres with respect to calibration and cross-calibration was observed. The reliability of our 18F-FLT multi-centre clinical trial was therefore confirmed from the physical point of view. This type of procedure may be useful for any clinical trial involving different PET systems.

Unusual uptake of 18FDG by a hepatic adenoma.

Hepatic adenoma is a rare, benign tumor (with potential for malignant degeneration) and its diagnosis is difficult because its presentation is highly variable in medical imaging, particularly with MRI. In such cases, the use of a hepatic biopsy is usually recommended. (18)FDG-PET/CT provides a very significant predictive value for malignant hepatic lesions. In addition, the occurrence of an (18)FDG-avid benign tumor is a rare event. We hereby present the case of a patient with advanced breast cancer for whom an (18)FDG-PET/CT showed a focal hepatic uptake. A subsequent biopsy provided a diagnosis of a hepatic adenoma.

Tumor eradication in rat glioma and bypass of immunosuppressive barriers using internal radiation with (188)Re-lipid nanocapsules.

To date, glioblastoma treatments have only been palliative. In this context, locoregional drug delivery strategies, which allow for blood--brain barrier bypass and reduced systemic toxicity, are of major significance. Recent progress in nanotechnology has led to the development of colloidal carriers of radiopharmaceutics, such as lipid nanocapsules loaded with rhenium-188 (LNC(188)Re-SSS) that are implanted in the brain. In our study, we demonstrated that fractionated internal radiation using LNC(188)Re-SSS triggered remarkable survival responses in a rat orthotopic glioma model (cure rates of 83%). We also highlighted the importance of the radioactivity activity gradient obtained by combining a simple stereotactic injection (SI) with convection-enhanced delivery (CED).We assumed that the immune system played a role in the treatment's efficacy on account of the overproduction of peripheral cytokines, recruitment of immune cells to the tumor site, and memory response in long-term survivor animals. Hence, nanovectorized internal radiation therapy with activity gradients stimulating immune responses may represent a new and interesting alternative for the treatment of solid tumors such as glioblastomas.