FDG-PET/CT in the Monitoring of Lymphoma Immunotherapy Response: Current Status and Future Prospects

Cancer immunotherapy has been extensively investigated in lymphoma over the last three decades. This new treatment modality is now established as a way to manage and maintain several stages and subtypes of lymphoma. The establishment of this novel therapy has necessitated the development of new imaging response criteria to evaluate and follow up with cancer patients. Several FDG PET/CT-based response criteria have emerged to address and encompass the various most commonly observed response patterns. Many of the proposed response criteria are currently being used to evaluate and predict responses. The purpose of this review is to address the efficacy and side effects of cancer immunotherapy and to correlate this with the proposed criteria and relevant patterns of FDG PET/CT in lymphoma immunotherapy as applicable. The latest updates and future prospects in lymphoma immunotherapy, as well as PET/CT potentials, will be discussed.

Efficacy and safety of front-line treatments for advanced Hodgkin lymphoma: a systematic literature review

OBJECTIVE

To assess evidence on the safety and efficacy of ABVD (doxorubicin [Adriamycin®], bleomycin, vinblastine, and dacarbazine), BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone), and A+AVD (brentuximab vedotin, with doxorubicin, vinblastine, and dacarbazine) for advanced-stage Hodgkin lymphoma (HL).

METHODS

A systematic literature review (SLR) was conducted on 29 July 2016 (updated 26 July 2018) to identify randomized controlled trials (RCTs) and non-RCTs assessing the treatment of newly-diagnosed advanced-stage HL with ABVD and BEACOPP (and their variants), and A+AVD.

RESULTS

The SLR identified 62 RCTs and 42 non-RCTs. Five-year overall survival rates for ABVD and BEACOPP were 60-97% and 84-99%, and 5-year progression-free survival rates were 58-81% and 83-96%, respectively. Both regimens were associated with tolerability issues and side effects. Discontinuation or dose reduction of bleomycin resulted in fewer adverse events, without significantly affecting efficacy. A head-to-head trial demonstrated improved efficacy for A+AVD vs ABVD, with an acceptable tolerability profile. No data from head-to-head trials comparing A+AVD with BEACOPP were available, and an indirect treatment comparison was not feasible.

CONCLUSION

New therapies, such as A+AVD, maintain the efficacy observed with current treatments, and may provide a more tolerable treatment option for patients with advanced-stage HL.

FDA's and EMA's approval of brentuximab vedotin for advanced Hodgkin lymphoma: Another player in the town?

ECHELON-1 study is a randomized open-labeled controlled trial investigating whether addition of brentuximab vedotin to chemotherapy offers benefit over the standard chemotherapy regimen in advanced Hodgkin lymphoma. After a median follow-up of 24.6 months, it has met its primary endpoint the reduction of modified progression-free survival being 23 percent. However, the beneficial effects have not been seen across all subgroups leading to further questions. The main aim of this review is to tackle these questions to provide the reader with in-depth insight of pros and cons of this novel, promising but ultimately controversial regimen.

Risk-adapted therapy for advanced-stage Hodgkin lymphoma

More than 80% of patients with advanced-stage Hodgkin lymphoma are now cured with contemporary treatment approaches. The ongoing challenge is how to further improve outcomes by identifying both high-risk patients who may benefit from more intensive frontline therapy to reduce the risk of relapse as well as lower-risk patients who may do just as well with less intensive therapy. Numerous trials have used an interim positron emission tomography (PET) response-adapted approach to evaluate early escalation or deescalation of therapy for patients with a positive or negative interim PET scan, respectively. Recent trials have incorporated novel agents, including brentuximab vedotin (BV) and the immune checkpoint inhibitors, in the frontline setting. Based on results of the ECHELON-1 trial, the Food and Drug Administration approved BV in combination with adriamycin, vinblastine, and dacarbazine chemotherapy for stage III to IV Hodgkin lymphoma. Improved methods to assess higher risk at diagnosis using quantitative PET metrics, such as metabolic tumor volume and total lesion glycolysis, and incorporation of emerging biomarkers may further refine patient selection for more intensive upfront therapy. The ultimate goal is to achieve the highest level of efficacy for an individual patient while minimizing the short- and long-term toxicities.