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The prospective randomized Positron Emission Tomography (PET)-Guided Therapy of Aggressive Non-Hodgkin Lymphomas (PETAL) trial was designed to test the ability of interim PET (iPET) to direct therapy. As reported previously, outcome remained unaffected by iPET-based treatment changes. In this subgroup analysis, we studied the prognostic value of baseline total metabolic tumor volume (TMTV) and iPET response in 76 patients with T-cell lymphoma. TMTV was measured using the 41% maximum standardized uptake value (SUV 41max ) and SUV 4 thresholding methods. Interim PET was performed after two treatment cycles and evaluated using the ΔSUV max approach and the Deauville scale. Because of significant differences in outcome, patients with anaplastic lymphoma kinase (ALK)-positive lymphoma were analyzed separately from patients with ALK-negative lymphoma. In the latter, TMTV was statistically significantly correlated with progression-free survival, with thresholds best dichotomizing the population, of 232 cm 3 using SUV 41max and 460 cm 3 using SUV 4 . For iPET response, the respective thresholds were 46.9% SUV max reduction and Deauville score 1-4 vs 5. The proportion of poor prognosis patients was 46% and 29% for TMTV by SUV 41max and SUV 4 , and 29% and 25% for iPET response by ΔSUV max and Deauville, respectively. At diagnosis, the hazard ratio (95% confidence interval) for poor prognosis vs good prognosis patients according to TMTV was 2.291 (1.135-4.624) for SUV 41max and 3.206 (1.524-6.743) for SUV 4 . At iPET, it was 3.910 (1.891-8.087) for ΔSUV max and 4.371 (2.079-9.187) for Deauville. On multivariable analysis, only TMTV and iPET response independently predicted survival. Patients with high baseline TMTV and poor iPET response (22% of the population) invariably progressed or died within the first year (hazard ratio, 9.031 [3.651-22.336]). Due to small numbers and events, PET did not predict survival in ALK-positive lymphoma. Baseline TMTV and iPET response are promising tools to select patients with ALK-negative T-cell lymphoma for early allogeneic transplantation or innovative therapies., (© 2019 John Wiley & Sons, Ltd.)

Standard first-line treatment of aggressive B cell lymphoma comprises six or eight cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus eight doses of rituximab (R). Whether adding two doses of rituximab to six cycles of R-CHOP is of therapeutic benefit has not been systematically investigated. The Positron Emission Tomography-Guided Therapy of Aggressive Non-Hodgkin Lymphomas (PETAL) trial investigated the ability of [ 18 F]-fluorodesoxyglucose PET scanning to guide treatment in aggressive non-Hodgkin lymphomas. Patients with B cell lymphomas and a negative interim scan received six cycles of R-CHOP with or without two extra doses of rituximab. For reasons related to trial design, only about a third underwent randomization between the two options. Combining randomized and non-randomized patients enabled subgroup analyses for diffuse large B cell lymphoma (DLBCL; n = 544), primary mediastinal B cell lymphoma (PMBCL; n = 37), and follicular lymphoma (FL) grade 3 (n = 35). With a median follow-up of 52 months, increasing the number of rituximab administrations failed to improve outcome. A non-significant trend for improved event-free survival was seen in DLBCL high-risk patients, as defined by the International Prognostic Index, while inferior survival was observed in female patients below the age of 60 years. Long-term outcome in PMBCL was excellent. Differences between FL grade 3a and FL grade 3b were not apparent. The results were confirmed in a Cox proportional hazard regression model and a propensity score matching analysis. In conclusion, adding two doses of rituximab to six cycles of R-CHOP did not improve outcome in patients with aggressive B cell lymphomas and a fast metabolic treatment response.

Purpose: The objective of this study was to evaluate positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D-glucose (FDG) in comparison to volumetry and standardized magnetic resonance imaging (MRI) parameters for the assessment of histological response in paediatric bone sarcoma patients., Methods: FDG PET and local MRI were performed in 27 paediatric sarcoma patients [Ewing sarcoma family of tumours (EWS), n = 16; osteosarcoma (OS), n = 11] prior to and after neoadjuvant chemotherapy before local tumour resection. Several parameters for assessment of response of the primary tumour to therapy by FDG PET and MRI were evaluated and compared with histopathological regression of the resected tumour as defined by Salzer-Kuntschik., Results: FDG PET significantly discriminated responders from non-responders using the standardized uptake value (SUV) reduction and the absolute post-therapeutic SUV (SUV2) in the entire patient population (SUV, p = 0.005; SUV2, p = 0.011) as well as in the subgroup of OS patients (SUV, p = 0.009; SUV2, p = 0.028), but not in the EWS subgroup. The volume reduction measured by MRI/CT did not significantly discriminate responders from non-responders either in the entire population (p = 0.170) or in both subgroups (EWS, p = 0.950; OS, p = 1.000). The other MRI parameters alone or in combination were unreliable and did not improve the results. Comparing diagnostic parameters of FDG PET and local MRI, metabolic imaging showed high superiority in the subgroup of OS patients, while similar results were observed in the population of EWS., Conclusion: FDG PET appears to be a useful tool for non-invasive response assessment in the group of OS patients and is superior to MRI. In EWS patients, however, neither FDG PET nor volumetry or standardized MRI criteria enabled a reliable response assessment to be made after neoadjuvant treatment.

Purpose: This prospective single-centre phase II trial assessed the diagnostic impact of (18)F-FDG PET-CT in the evaluation of solid pancreatic lesions (phi >or= 10 mm) compared to endosonography (EUS), endoscopic retrograde cholangio-pancreatography (ERCP) with intraductal ultrasound (IDUS), abdominal ultrasound (US) and histopathological reference., Methods: Forty-six patients (32 men/14 women, phi 61.7 years) with suspected pancreatic neoplasms underwent PET-CT with contrast-enhanced biphasic multi-detector CT of the upper abdomen followed by a diagnostic work-up with EUS, ERCP with IDUS and US within 3 weeks. PET-CT data sets were analysed by two expert readers in a consensus reading. Histology from surgery, biopsy/fine-needle aspiration and/or clinical follow-up >or=12 months served as standard of reference., Results: Twenty-seven pancreatic malignancies were histopathologically proven; 19 patients had benign diseases: 36/46 lesions (78%) were detected in the head of the pancreas, 7/46 and 3/46 in the body and tail region, respectively. Sensitivity and specificity of PET-CT were 89% and 74%, respectively; positive predictive value (PPV) and negative predictive value (NPV) were 83% and 82%, respectively. Sensitivity (81-89%), specificity (74-88%), PPV (83-90%) and NPV (77-82%) achieved by EUS, ERCP and US were not significantly different. PET analysis revealed significantly higher maximum mean standardised uptake values (SUV(max) 6.5+/-4.6) in patients with pancreatic malignancy (benign lesions: SUV(max) 4.2+/-1.5; p<0.05). PET-CT revealed cervical lymphonodal metastasis from occult bronchogenic carcinoma and a tubular colon adenoma with intermediate dysplasia on polypectomy, respectively., Conclusions: (18)F-FDG PET-CT achieves a comparably high diagnostic impact evaluating small solid pancreatic lesions versus conventional reference imaging modalities. Additional clinical diagnoses are derived from concomitant whole-body PET-CT imaging.

Correctly staging lung cancer is extremely important because treatment options and prognosis differ significantly by stage. In this review, the performance characteristics of positron emission tomography using F-18-fluoro-deoxyglucose (FDG PET) for staging the mediastinum are given in comparison with other non-invasive imaging modalities on the basis of current literature data. There are three meta-analyses demonstrating that FDG PET is more accurate than CT for detecting mediastinal metastases. First publications suggest that dual-modality PET-CT may provide a further gain in accuracy. Additionally, whole-body FDG PET provides information on M-staging and prognosis. Data comparing FDG PET with other functional imaging modalities or endoscopic ultrasound are limited. The necessity of a histological confirmation of PET results is still under discussion.

Unlabelled: The purpose of this retrospective analysis was to evaluate the prognostic significance of both initial glucose metabolism as measured by (18)F-FDG PET and osteoblastic activity as measured by (99m)Tc-methylene diphosphonate (MDP) bone scintigraphy in osteosarcoma., Methods: In 29 patients (18 male, 11 female; age range, 5-41 y) with primary osteosarcoma, (18)F-FDG uptake and (99m)Tc-MDP uptake were measured semiquantitatively (average and maximum tumor-to-nontumor ratios [T/NT(av) and T/NT(max), respectively]) using PET and bone scintigraphy at the time of diagnosis. After chemotherapy, the patients underwent surgery for their primary tumor, and the response was determined histologically. Cumulative overall survival and event-free survival were determined by clinical and imaging follow-up of 7-72 mo (median, 28 mo)., Results: Clinical and imaging follow-up revealed that the disease relapsed or failed to achieve complete remission in 9 patients and that 6 patients died of the disease. Both overall and event-free survival were significantly better in patients with a low (18)F-FDG T/NT(max) (less than the median) than in patients with a high (18)F-FDG T/NT(max) (at least the median). The negative relationship of (18)F-FDG T/NT(av), (99m)Tc-MDP T/NT(max), and (99m)Tc-MDP T/NT(av) with overall and event-free survival did not reach a level of significance. (18)F-FDG uptake values correlated moderately and positively with (99m)Tc-MDP uptake values, but a level of significance was reached only between (18)F-FDG T/NT(max) and (99m)Tc-MDP T/NT(av)., Conclusion: The initial glucose metabolism of primary osteosarcoma as measured by (18)F-FDG PET using T/NT(max) provides prognostic information. High (18)F-FDG uptake correlates with poor outcome. Thus, (18)F-FDG uptake may be complementary to other well-known factors in judging the prognosis in osteosarcoma.