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Background: Surgical resection is considered to be of purely diagnostic value in aggressive lymphoma. Evidence for an impact on outcome is scant and restricted to retrospective observations. Methods: In the "Positron Emission Tomography‐guided Therapy of Aggressive non‐Hodgkin Lymphomas" (PETAL) trial, patients with a negative baseline positron emission tomography (PET) scan were documented in a prospective observational substudy. Baseline PET‐negative patients with the absence of lymph node enlargement on computed tomography and a negative bone marrow biopsy were considered to have undergone complete lymphoma resection. Results: Eighty‐two of 1,041 patients (7.9%) had a negative baseline PET scan, and 67 were included in this analysis. All were treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), plus rituximab for CD20‐positive lymphomas. Among 52 patients with diffuse large B‐cell lymphoma (DLBCL), 48 had completely resected disease. Their outcome tended to be better than that of 115 baseline PET‐positive stage I DLBCL patients treated in the main part of the PETAL trial (2‐year progression‐free survival 92.7% [95% confidence interval 84.7‐100] versus 88.4% [82.5‐94.3], P =.056; 2‐year overall survival 92.7% [84.7‐100] versus 93.7% [89.2‐98.2], P =.176), but this was restricted to patients below the age of 60 years (2‐year progression‐free survival 100% versus 92.2% [84.8‐99.6], P =.031; 2‐year overall survival 100% versus 95.9% [90.2‐100], P =.075). In peripheral T‐cell lymphoma, eight of 11 patients had completely resected disease. In contrast to DLBCL, complete resection was not associated with improved outcome compared to the control. Conclusion: Young patients with early stage DLBCL may benefit from complete lymphoma resection prior to immunochemotherapy. [ABSTRACT FROM AUTHOR]

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 (SUV41max ) and SUV4 thresholding methods. Interim PET was performed after two treatment cycles and evaluated using the ΔSUVmax 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 cm3 using SUV41max and 460 cm3 using SUV4 . For iPET response, the respective thresholds were 46.9% SUVmax reduction and Deauville score 1-4 vs 5. The proportion of poor prognosis patients was 46% and 29% for TMTV by SUV41max and SUV4 , and 29% and 25% for iPET response by ΔSUVmax 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 SUV41max and 3.206 (1.524-6.743) for SUV4 . At iPET, it was 3.910 (1.891-8.087) for ΔSUVmax 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. [ABSTRACT FROM AUTHOR]

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 [18F]-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. [ABSTRACT FROM AUTHOR]

Summary: 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. [Copyright &y& Elsevier]