Impact of Routine Surveillance Imaging on Outcomes of Patients With Diffuse Large B-Cell Lymphoma After Autologous Hematopoietic Cell Transplantation

ASTCT Committee on Practice Guidelines Survey on Evaluation & Management of Diffuse Large B-cell Lymphoma after Failure of Chimeric Antigen Receptor T Cell Therapy (CAR-T) Therapy

Chimeric antigen receptor T-cell therapy (CAR-T) is a major advance in managing aggressive relapsed or refractory B-cell lymphomas; however, relapses are frequent and pose a major therapeutic challenge. There is substantial variability across transplantation and cellular therapy programs in assessing and managing post-CAR-T failures. The American Society for Transplantation and Cellular Therapy Committee on Practice Guidelines conducted an online cross-sectional survey between August 2021 and October 2021 to determine the U.S. lymphoma and transplantation and cellular therapy physicians' practice patterns for the detection and diagnosis of CAR-T failure, as well as management strategies for diffuse large B-cell lymphoma in this particular setting. E-mail surveys were sent to 901 potential participants, of which 174 (19%) completed the survey. Responders were mainly White (51.2%), male (70.7%), and with >10 years of practice experience (51.2%). Overall, 87% of the responders were affiliated with university/teaching centers; 54.6% had general oncology practices, and 45.4% had lymphoma-focused transplantation/cellular therapy practices. The most common periods to perform surveillance scans were at 3 months and 12 months after CAR-T infusion. Overall, 88.5% of responders would often or always consider a biopsy to confirm relapse and 89% would routinely check for the persistence of the antigen targeted by the CAR (e.g., CD19 in the case of CD19 CAR-T). The most popular first salvage regimen for relapse or progression was an alternate CAR-T therapy (dual or alternate target) regardless of CD19 positivity. Twenty-seven percent of responders chose this regimen for CD19 positive relapse, whereas 31% of responders did so for CD19 negative relapse. Overall, 88.5% of responders favored consolidative allogeneic hematopoietic cell transplantation after response to salvage, whereas 51.2% of physicians would consider autologous hematopoietic cell transplantation in transplantation-naïve patients. There is substantial cross-center variation in surveillance, diagnosis, and management of CAR-T failure. Prospective clinical trials evaluating novel agents in this setting are urgently needed to identify best management strategies.

The role of surveillance computed tomography in patients with follicular lymphoma

Introduction

Surveillance computed tomography (CT) is performed during the follow-up of patients with lymphoma who have completed initial therapy. However, studies on the clinical benefit of surveillance CT for patients with incurable subtypes, such as follicular lymphoma (FL), are limited. This study aimed to evaluate the value of surveillance CT for patients with FL after achieving the first complete response (CR) or CR unconfirmed in the rituximab era.

Methods

We retrospectively reviewed the medical records of patients with FL who achieved CR with first-line treatment between 2000 and 2016 at our institution. In patients who experienced first relapse, we examined the patient's clinical characteristics at the time of relapse, subsequent therapies, and post-relapse survival, based on the method of relapse detection.

Results

Of the 248 patients who achieved CR after initial therapy, 109 had a relapse, with a median follow-up of 11 years; 100 were enrolled into this study. Relapse was detected by surveillance CT in 61 patients (surveillance CT group) and by means other than surveillance CT, such as the presence of patient-reported symptoms, physical findings, and blood work-up abnormalities (non-surveillance CT group), in 39 patients. There was no significant difference in the patients' characteristics at the time of relapse between the two groups, except for a higher incidence of extranodal involvement in the non-surveillance CT group. The method of relapse detection did not affect therapeutic selection after relapse and post-relapse survival. In this study, 86.8% of the 38 patients who relapsed with only deep lesions, such as mesenteric or retroperitoneal lymph nodes, had surveillance CT-detected relapse.

Conclusion

Surveillance CT did not show any clinical benefit for patients with FL in CR; however, it might lead to early detection of relapse in cases of deep lesions that cannot be identified without imaging.

Surveillance in Patients With Diffuse Large B Cell Lymphoma

With improvement in the cure rates for diffuse large B cell lymphoma, the question of surveillance imaging in patients who achieve complete remission after the initial therapy has become relevant. Some of the clinical practice guidelines recommend surveillance scanning. However, several studies have reported no benefit in overall survival with scans. Moreover, studies have highlighted an increased risk for developing secondary malignancies because of exposure to ionizing radiation from the scans. Different international societies have contrasting guidelines for the role of surveillance computerized tomography scans in patients who achieve complete remission after first-line therapy. Any benefit of surveillance imaging must be balanced by the costs, risk of radiation exposure, and lack of survival benefit. The PubMed platform was searched using relevant keywords for English-language articles with no date restrictions. Search terms were cross-referenced with review articles, and additional articles were identified by manually searching reference lists. Results were reviewed by the authors and selected for inclusion based on relevance. We present a review of this current data available for surveillance imaging in patients with diffuse large B cell lymphoma.

Surveillance Imaging after Autologous Hematopoietic Cell Transplantation Predicts Survival in Patients with Diffuse Large B Cell Lymphoma

The utility of surveillance imaging after autologous hematopoietic cell transplantation (AHCT) in relapsed/refractory diffuse large B cell lymphoma (DLBCL) remains unclear. The purpose of this study was to determine whether surveillance imaging predicts survival after AHCT. At the University of Minnesota, serial imaging for early relapse detection has been used prospectively for all consecutive AHCT recipients treated since 2010. The present analysis included 91 AHCT recipients with DLBCL who underwent ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET) scan at day +100 post-AHCT. ¹⁸F-FDG-PET parameters included the Deauville (D) 5-point scale, peak standardized uptake values (SUV_max), total legion glycolysis (TLG), and total metabolic tumor volume (TMTV). Survival of patients with clinically symptomatic versus asymptomatic radiographically detected relapsed DLBCL after AHCT was compared. Sixty patients experienced relapse; 35% was detected on day +100 surveillance PET scan. 5-year overall survival (OS) by ¹⁸F-FDG-PET scan at day +100 post-AHCT was significantly lower in D4 and D5 patients (37%; 95% confidence interval [CI], 14% to 100% versus 25%; 95% CI, 43% to 89%) compared with patients with D1 and D2 (62%; 95% CI, 43% to 89% versus 62%; 95% CI, 46% to 84%). TLG and TMTV were not prognostic. SUV_max at day +100 varied from 1.5 (D1) to 17.9 (D5). In multivariate analysis, only SUV_max was predictive of relapse and OS; mortality increased 1.8-fold with each SUV_max doubling (hazard ratio [HR], 1.8; 95% CI, 1.3 to 2.3; P < .01). At a median follow-up of 3.3 years (range, 1 to 12 years), lymphoma-related mortality was 1.8-fold higher among patients whose relapse was detected clinically (symptomatic) versus radiographically on surveillance scan (HR, 1.8; 95% CI, .9 to 3.4; P = .08). In patients with relapsed/refractory DLBCL, a routine PET imaging at day +100 post-AHCT detects asymptomatic relapse and high SUV_max identifies patients with poor expected survival of less than 1 year. Identifying this high-risk cohort can potentially highlight patients who might benefit from preemptive interventions to prevent or delay relapse.

Utility of routine surveillance imaging for diffuse large B-cell lymphoma post autologous transplant: A single center experience

Surveillance scans after autologous stem cell transplant (auto-HCT) for patients with relapsed/refractory (RR) diffuse large B Cell lymphoma (DLBCL) have no proven survival benefit. We studied survival differences among patients with RR DLBCL post auto-HCT whose recurrences were detected clinically versus with routine surveillance imaging. Among the 139 patients with RR DLBCL that underwent auto-HCT from 2000 to 2014 at our institution, 37 relapsed: 21 clinical and 16 radiological. The median time to progression was 167 days for the clinical cohort and 565 days for the radiological cohort (p = 0.03), and median overall survival (OS) was 587 days and not reached, respectively (p = 0.006). Most patients with relapsed DLBCL after auto-HCT were diagnosed clinically and were likely to be detected earlier and have a shorter OS. Relapse in patients with aggressive disease will likely be detected when clinically apparent, and the outcome of these patients is independent of the way the relapse is diagnosed. Thus, universal scanning after auto-HCT appears to have little benefit.

Are We Choosing Wisely in Lymphoma? Excessive Use of Surveillance CT Imaging in Patients With Diffuse Large B-cell Lymphoma (DLBCL) in Long-term Remission

INTRODUCTION

The use of surveillance computed tomography (CT) imaging in patients with diffuse large B-cell lymphoma in remission is neither effective nor cost-effective. The American Society of Hematology Choosing Wisely (CW) campaign, in particular, emphasizes the lack of benefit beyond 2 years of completion of therapy. We sought to describe the real-world practice of surveillance imaging.

PATIENTS AND METHODS

We used population-based health system administrative databases from Ontario, Canada. We studied a cohort of all adult patients ≥ 18 years with diffuse large B-cell lymphoma who received rituximab (R) with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) between 2004 and 2012. We defined an index date of 2 years after the last dose of RCHOP as the time frame beyond which surveillance imaging would be inappropriate. The cumulative incidence of receiving CT scans after the index date represented the primary outcome of interest.

RESULTS

The cohort consisted of 2401 patients treated with RCHOP during the study period. The cumulative incidence reached 52.5% (range, 50.4%-54.6%) by 3 years of follow-up. On multivariable analysis, patients with more comorbidities and within certain geographic regions within the province were noted to have increased CT scanning. The cumulative incidence appeared to decrease over the study follow-up period (from 62.4% in 2006 to 48.0% in 2014; P < .001).

CONCLUSION

During a timeframe in which surveillance imaging is deemed unnecessary by the CW campaign, the practice remains excessive. Regional variations in CT scanning suggest that local practice patterns can be targeted to reduce imaging. A recent decline in scanning may reflect a broadening appreciation for the evidence against surveillance or uptake of the CW campaign.