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As part of a randomized, prospective clinical trial in large cell lymphoma, we conducted serial fluorodeoxyglucose positron emission tomography (FDG-PET) at baseline, after 2 cycles of chemotherapy (interim PET [i-PET]), and at end of treatment (EoT) to identify biomarkers of response that are predictive of remission and survival. Scans were interpreted in a core laboratory by 2 imaging experts, using the visual Deauville 5-point scale (5-PS), and by calculating percent change in FDG uptake (change in standardized uptake value [ΔSUV]). Visual scores of 1 through 3 and ΔSUV ≥66% were prospectively defined as negative. Of 524 patients enrolled in the parent trial, 169 agreed to enroll in the PET substudy and 158 were eligible for final analysis. In this selected population, all had FDG-avid disease at baseline; by 5-PS, 55 (35%) remained positive on i-PET and 28 (18%) on EoT PET. Median ΔSUV on i-PET was 86.2%. With a median follow-up of 5 years, ΔSUV, as continuous variable, was associated with progression-free survival (PFS) (hazard ratio [HR] = 0.99; 95% confidence interval [CI], 0.97-1.00; P = .02) and overall survival (OS) (HR, 0.98; 95% CI, 0.97-0.99; P = .03). ΔSUV ≥66% was predictive of OS (HR, 0.31; 95% CI, 0.11-0.85; P = .02) but not PFS (HR, 0.47; 95% CI, 0.19-1.13; P = .09). Visual 5-PS on i-PET did not predict outcome. ΔSUV, but not visual analysis, on i-PET predicted OS in DLBCL, although the low number of events limited the statistical analysis. These data may help guide future clinical trials using PET response-adapted therapy. This trial was registered at www.clinicaltrials.gov as #NCT00118209.

A negative interim positron emission tomography/computerized tomography (PET/CT) after 1 to 3 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) in patients with newly diagnosed, nonbulky stage I or II Hodgkin lymphoma (HL) predicts a low relapse rate. This phase 2 trial was designed to determine if a population of patients with early-stage disease can be treated with short-course ABVD without radiation therapy (RT) on the basis of a negative interim PET/CT, thereby limiting the risks of treatment. Between 15 May 2010 and 21 February 2013, 164 previously untreated patients with nonbulky stage I/II HL were enrolled, and 149 were included in the final analysis. Patients received 2 cycles of ABVD followed by PET. Deauville scores 1 to 3 were negative (≤ liver uptake) based on central review. PET - patients received 2 more cycles of ABVD, and PET + patients received 2 cycles of dose-intense bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (escalated BEACOPP) plus 3060-cGy involved-field RT. The primary objective was to determine 3-year progression-free survival (PFS) for the PET - group. One hundred thirty-five patients (91%) were interim PET - , and 14 patients (9%) were PET + With median follow-up time of 3.8 years, the estimated 3-year PFS was 91% for the PET - group and 66% for the PET + group (hazard ratio, 3.84; 95% confidence interval, 1.50-9.84; P = .011). There was 1 death as a result of suicide. Four cycles of ABVD resulted in durable remissions for a majority of patients with early-stage nonbulky HL and a negative interim PET. This trial was registered at www.clinicaltrials.gov as #NCT01132807., (© 2018 by The American Society of Hematology.)

Given the excellent survival rates for early-stage Hodgkin lymphoma (HL), the young age of many patients, and concerns regarding acute and late treatment-related toxicities, there is a desire to have a predictive tool that enables therapy to be tailored toward the individual patient. Early (or interim) (18)F-fluorodeoxyglucose positron emission tomography with computerized tomography (FDG-PET/CT), as a test of tumor sensitivity to ongoing/planned therapy, has been shown to be prognostic for survival in HL. Based on results of interim FDG-PET/CT, therapy may be subsequently modified through minimization or via intensification for low- and high-risk patient populations, respectively (ie, response-adapted therapy). Important data have been generated to standardize the interpretability and reproducibility of interim FDG-PET/CT (eg, the Deauville 5-point system), and observational and noncontrolled prospective studies have produced evidence supporting the hypothesis that response-adapted therapy may potentially serve as a predictive tool. Furthermore, results from noninferiority phase 3 clinical trials randomizing early-stage HL patients with negative interim FDG-PET/CT to combined modality therapy versus chemotherapy alone have been reported. The current collective findings from these randomized early-stage HL studies have shown that acute relapse rates are lower with combined modality therapy, even in patients with negative interim FDG-PET/CT. Additional randomized response-adapted studies are ongoing and novel FDG-PET/CT applications involving quantitative techniques and innovative imaging modalities are being investigated to identify more robust imaging biomarkers. Treatment of early-stage HL remains a clinical management choice for physicians and patients to make with consideration of acute and long-term outcomes., (© 2014 by The American Society of Hematology. All rights reserved.)

Despite the rewarding results achieved in the treatment of Hodgkin lymphoma (HL), concerns have been raised regarding the long-term complications induced by therapy. Hence, the current challenge is to develop a new therapeutic strategy maintaining excellent patient outcome while reducing potentially life-threatening late adverse effects. Therefore, it would be beneficial to identify chemoresistant or refractory patients early during therapy for appropriate and timely escalation of treatment. Recently, compelling data have emerged on the prognostic role of interim [18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) performed early during the course of treatment to predict ultimate outcome, even proving superior to conventional prognostic factors. Several ongoing prospective trials are exploring the feasibility of treatment de-escalation strategies in patients with a negative interim PET, as well as therapy escalation in advanced-stage HL patients who have a positive interim PET result. In this article, the published reports on the contribution of interim PET to the design of ongoing response-adapted clinical trials are reviewed. Moreover, some of the unresolved issues revolving around the suboptimal positive predictive value of interim PET are addressed with an emphasis on the interpretation criteria. A final remark on the appropriate use of interim PET is also provided.

To reduce doxorubicin, bleomycin, vinblastine and dacarbazine toxicity, the Cancer and Leukemia Group B conducted a phase 2 trial of doxorubicin, vinblastine, and gemcitabine for newly diagnosed, nonbulky stages I and II Hodgkin lymphoma. Ninety-nine assessable patients received 6 cycles of doxorubicin 25 mg/m(2), vinblastine 6 mg/m(2), and gemcitabine 800 mg/m(2) (1000 mg/m(2) in first 6) on days 1 and 15 every 28 days. Computed tomography (CT) and positron emission tomography (PET) were performed before and after 2 and 6 cycles. Complete remission (CR)/CR unconfirmed was achieved in 72 of 99 patients (72.7%) and partial remission in 24 of 99 patients (24.2%). The CR rate was 81% when using PET criteria. Two patients have died of Hodgkin lymphoma progression. Median follow-up for nonprogressing patients is 3.3 years. The progression-free survival (PFS) at 3 years was 77% (95% confidence interval, 68%-84%). The relapse rate was less than 10% for patients with favorable prognostic factors. The 2-year PFS for cycle 2 PET-negative and -positive patients was 88% and 54%, respectively (P = .0009), compared with 89% and 27% for cycle 6 PET-negative and -positive patients (P = .0001). Although the CR rate and PFS were lower than anticipated, patients with favorable prognostic features had a low rate of relapse. Cycle 2 PET and cycle 6 PET were predictive of PFS.