Phase II study of interim PET-CT-guided response-adapted therapy in advanced Hodgkin's lymphoma

Cost-effectiveness of response-adapted therapy (RAT) for advanced Hodgkin's Lymphoma compared with conventional treatment in India: a Markov-model based analysis

Cost effectiveness analysis of interim positron emission tomography (PET-2, done after 2 cycles of chemotherapy) based response adaptive therapy (RAT) approaches in advanced Hodgkin lymphoma (aHL) are not available from an Indian perspective. We used a five-year decision analytics model to assess the cost-effectiveness of the two RAT approaches [(escalation (RAT-1) or de-escalation (RAT-2)] compared with standard care (SOC) in aHL (mean age:35 years). Modelling data was derived from secondary sources and sensitivity analyses were performed to assess the robustness of the model. Net monetary benefit (NMB) gained from RAT2 in Indian rupees (INR) (INR 2,26,896) was higher than the RAT1 (INR 1,83,138) when compared with SOC. Proportion achieving the complete response after initial treatment (CR1) was the key determining factor for the RAT1/2 dominance over SOC. Despite higher initial input costs, response-adapted therapy of aHL was cost-effective by minimizing the cost incurred and disutility experienced during relapse and salvage.

Outcomes Among Classical Hodgkin Lymphoma Patients After an Interim PET Scan: A Real-World Experience

INTRODUCTION

The utility of dose escalation after positive positron emission tomography following 2 cycles of ABVD (PET2) for Hodgkin Lymphoma (HL) remains controversial. We describe the United States real-world practice patterns for PET2 positive patients.

PATIENTS AND METHODS

Data was collected from 15 sites on PET2 positive HL patients after receiving frontline treatment between January, 2015 and June, 2019. Descriptive analyses between those with therapy change and those continuing initial therapy were assessed.

RESULTS

A total of 129 patients were identified; 111 (86%) were treated with ABVD therapy and 18 (14%) with an alternate regimen. At PET2 assessment, 74.4% (96/129) had Deauville score (DS) 4 and 25.6% (33/129) had DS 5. Of the 66 limited stage (LS) patients with PET2 DS score of 4/5, 77.3% (51/66) continued initial therapy and 22.7% (15/66) changed to escalated therapy. The 12-month progression-free survival (PFS) for DS 4/5 LS patients was 67.0% (95% CI; 54.9-81.7) for patients without escalation compared with 51.4% (95% CI; 30.8-85.8) for those who escalated. Of the 63 DS 4/5 patients with advanced stage (AS) disease, 76.2% (48/63) continued initial therapy and 23.8% (15/63) changed to escalated therapy. The 12-month PFS for DS 4/5 AS patients was 38.3% (95% CI: 26.3%-55.7%) for patients without escalation compared with 57.1% (95% CI: 36.3-89.9) for those with escalation.

CONCLUSION

A minority of PET2 positive HL patients undergo therapy escalation and outcomes remain overall suboptimal. Improved prognostics markers and better therapeutics are required to improve outcomes for high-risk PET2 positive HL patients.

Real-World Outcomes of Hodgkin Lymphoma: A Multi-Centric Registry From India

Background

Hodgkin’s lymphoma (HL) is one of the most curable malignancies with a 5-year survival of over 80%. Most published literature from low-middle income countries comes from single institute experience.

Methodology

The OncoCollect Lymphoma group registry was set up in 2017 and has 9 major participating sites across India. Data of newly diagnosed classical HL (CHL) patients, treated between 2011 and 2017, were collected using OncoCollect software. The clinical features, subtypes, prognostic stratification, treatment patterns, response to first-line treatment, and 5-year outcomes were analyzed. All statistical analysis was done using Microsoft R Open statistical software linked to OncoCollect software.

Results

There were 939 newly diagnosed CHL patients with a median age of 38 (range, 18–99) years at presentation. The male-to-female ratio was 2.07:1. Histological subtypes included mixed cellularity, CHL (MC, CHL), nodular sclerosis, CHL (NS, CHL), lymphocyte-rich, CHL (LR, CHL), and lymphocyte-depleted, CHL (LD, CHL), in 60.60%, 26.94%, 9.80%, and 2.66%, respectively. At presentation, 50.43% had B symptoms and 53.35% had advanced disease. 29.71% of advanced-stage patients had high Hodgkin IPI score. 79% and 21% of patients received 1st-line treatment with chemotherapy alone or combined modality treatment with chemotherapy and radiotherapy. The most common first-line chemotherapy was ABVD-based regimen (94.68%). The overall response rate was 93.48%. Complete response rates among early-stage favorable and unfavorable risk groups were 92.73% and 86.79%, and those among advanced-stage low- and high-risk groups were 76.64% and 69.78%, respectively. The median relapse-free follow-up duration was 51 months (IQR 22–69). A significant difference was found in 5-year EFS between the early- and advanced-stage disease 83.53% and 73.55% (p = 0.00087), respectively. Similarly, significant difference was found in EFS among early-stage patients treated with a combination of 4-cycle chemotherapy and radiotherapy vs. chemotherapy alone 88.57% and 66.33% (p = 0.0042), respectively.

Conclusions

In this large cohort from India, survival of patients with HL was comparable to the developed world. With a median follow-up of 51 months, the 5-year EFS and OS of all patients were 78.24% and 83.63%, respectively.

PET/CT-Based Response Evaluation in Cancer-a Systematic Review of Design Issues

Positron emission tomography/x-ray computed tomography (PET/CT) has long been discussed as a promising modality for response evaluation in cancer. When designing respective clinical trials, several design issues have to be addressed, especially the number/timing of PET/CT scans, the approach for quantifying metabolic activity, and the final translation of measurements into a rule. It is unclear how well these issues have been tackled in quest of an optimised use of PET/CT in response evaluation. Medline via Ovid and Science Citation Index via Web of Science were systematically searched for articles from 2015 on cancer patients scanned with PET/CT before and during/after treatment. Reports were categorised as being either developmental or evaluative, i.e. focusing on either the establishment or the evaluation of a rule discriminating responders from non-responders. Of 124 included papers, 112 (90 %) were accuracy and/or prognostic studies; the remainder were response-curve studies. No randomised controlled trials were found. Most studies were prospective (62 %) and from single centres (85 %); median number of patients was 38.5 (range 5-354). Most (69 %) of the studies employed only one post-baseline scan. Quantification was mainly based on SUVmax (91 %), while change over time was most frequently used to combine measurements into a rule (79 %). Half of the reports were categorised as developmental, the other half evaluative. Most development studies assessed only one element (35/62, 56 %), most frequently the choice of cut-off points (25/62, 40 %). In summary, the majority of studies did not address the essential open issues in establishing PET/CT for response evaluation. Reasonably sized multicentre studies are needed to systematically compare the many different options when using PET/CT for response evaluation.

SUVmax-based assessment of PET response shows a superior specificity to Deauville criteria for predicting recurrence in Hodgkin's lymphoma

One of the limitations of ¹⁸FDG PET/CT for therapeutic evaluation in Hodgkin's Lymphoma is the relatively high rate of false positive uptake. SUV_max reduction (ΔSUV_max) and tumor/liver ratio (TLr) are promising tools for response assessment in lymphoma. We determined the optimal cutoff values for ΔSUV_max and TLr and compared them to Deauville score (DS) after two and four cycles chemotherapy (PET2 and PET4 respectively) and at the end of treatment PET (PETeot) on a cohort of 362 patients. TLr showed better diagnostic performances than DS for predicting 5-year progression-free survival (PFS), especially on early PET/CT assessments. Positive predictive values at PET2 for TLr, ΔSUV_max and DS were 51%, 34% and 31% respectively. On the multivariable analysis, significant predictive factors of PFS were TLr (at PET2, PET4 and PETeot) and ΔSUV_max (at PET4 and PETeot). DS was not significantly associated with PFS at any PET timing.

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.

PET-adapted approaches to primary therapy for advanced Hodgkin lymphoma

Recent results of randomized phase III studies of FDG-PET-adapted therapy for advanced Hodgkin lymphoma (HL) have clearly demonstrated benefit to alteration of treatment according to interim response, in particular regarding reducing toxicity while maintaining efficacy. However, these studies have differences in design including initial chemotherapy regimen, PET response criteria, patient populations enrolled, and inclusion of radiation, and report different results regarding efficacy and toxicities, which makes cross-trial comparisons difficult. Practitioners are presented with deciding which of these approaches will provide the optimum outcome, balancing toxicity and efficacy, and for which patient with advanced-stage HL. This review summarizes the observations reported from these trials and provides context to help guide physicians and patients in treatment decisions for advanced HL.

Does Interim PET Scan After 2 Cycles of ABVD Predict Outcome in Hodgkin Lymphoma? Real-World Evidence

PURPOSE

Escalated BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) improves overall survival (OS) in patients with Hodgkin lymphoma (HL) relative to ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) therapy. However, the associated higher cost and toxicity discourage clinicians from prescribing it. Identifying high-risk patients and administering escalated BEACOPP remains an effective strategy. We assessed the significance of interim positron emission tomography (iPET) scan after 2 cycles (iPET2) in identifying this high-risk subset.

PATIENTS AND METHODS

This cohort study used secondary data from 12 tertiary care centers in South India gathered over 10 years (2008-2018). OS, event-free survival (EFS), determinants of EFS, and complete response (CR) in iPET2 were assessed.

RESULTS

The study included 409 patients with HL (mean age, 34.5 years; male/female ratio, 1.4:1). The median duration of follow-up was 2.8 years. Of 409 patients, 63% underwent PET-based staging and 37% underwent computerized tomography (CT) staging. Stage IV (28.9%) and bone involvement (9.2%) were seen more often with PET than with CT staging (9.2% and 2%, respectively). Among 171 patients with iPET2 results, 24% did not achieve CR, and no factors were significantly associated. The 5-year EFS and OS rates of the entire cohort were 78% and 97%, respectively. The 5-year EFS and OS rates of patients with CR on iPET2 were 90% and 99%, respectively, whereas these were 65% and 100%, respectively, for patients not achieving CR. On univariable analysis, sex, stage, and iPET2 response significantly predicted inferior EFS. On multivariate analysis, only iPET2 response significantly predicted EFS (P < .000).

CONCLUSION

Our study supports the use of PET for staging and iPET2 for response assessment. Nonachievement of CR on iPET2 indicates unfavorable outcome, and such patients may benefit from more intensive treatment.

2-deoxy-2[F-18] fluoro-D-glucose positron emission tomography Deauville scale and core-needle biopsy to determine successful management after six doxorubicin, bleomycin, vinblastine and dacarbazine cycles in advanced-stage Hodgkin lymphoma

BACKGROUND

The clinical impact of the positivity of the Deauville scale (DS) of positron emission tomography (PET) performed at the end of doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) in patients with advanced Hodgkin lymphoma (HL), in terms of providing rationale to shift poor responders onto a more intensive regimen, remain to be validated by histopathology.

PATIENTS AND METHODS

This prospective trial involved patients with stage IIB/IV HL who after six ABVD cycles underwent PET (PET6) and core-needle cutting biopsy (CNCB) of 2-deoxy-2[F-18] fluoro-d-glucose (FDG)-avid lymph nodes. Patients received high-dose chemotherapy/autologous haematopoietic stem cell rescue (HDCT/AHSCR) if CNCB was positive for HL, alternatively, if CNCB or PET was negative, received observation or consolidation radiotherapy (cRT) on residual nodal masses, as initially planned. The end-point was 5-year progression-free survival (PFS).

RESULTS

In all, 43 of the 169 (25%) evaluable patients were PET6 positive (DS 4, 32; DS 5, 11). Among them, histology showed malignancy (HL) in 100% of DS 5 scores and in 12.5% of DS 4 scores. Fifteen patients with positive biopsy received HDCT/AHSCR, whereas 28 patients with negative biopsy, as well as 126 patients with negative PET6, continued the original plan (cRT, 78 patients; observation, 76 patients). The 5-year PFS in the negative PET6 group, negative biopsy group and positive biopsy group was 95.4%, 100% and 52.5%, respectively.

CONCLUSION

DS positivity of end-of-ABVD PET in advanced HL carried a certain number of CNCB-proven non-malignant FDG-uptakes. The DS 4 scores which were found to have negative histology appeared to benefit from continuing the original non-intensive therapeutic plane as indicated by the successful outcome in more than 95% of them by obtaining similar 5-year PFS to the PET6-negative group. By contrast, the DS 5 score had consistently positive histology and was associated with unsuccessful conventional therapy, promptly requiring treatment intensification or innovative therapeutic approaches.

Gemcitabine, vinorelbine and dexamethasone: A safe and effective regimen for treatment of relapsed/refractory hodgkin's lymphoma

BACKGROUND

Salvage regimens in relapsed/refractory Hodgkin's lymphoma (HL) differ in their efficacy and toxicity profiles. Gemcitabine (G), vinorelbine (V) and liposomal doxorubicin (GVDoxil) is one regimen with high response rates but has high toxicity and cost. We devised a regimen of GVDex by substituting the more expensive liposomal doxorubicin with the cheaper high-dose dexamethasone (Dex).

PATIENTS AND METHODS

We analyzed the data of 48 adult and paediatric patients of relapsed/refractory HL who received GVDex as salvage therapy. GVDex was delivered as outpatient once in 3 weeks (Q3 weekly) (G 1000 mg/m² IV over 30 min on D1, 8; V 25 mg^/m² IV fast infusion on D1, 8; Dex40 mg PO D1-4) for 2-3 cycles. We present the overall response rate, toxicity, progression-free (PFS) and overall survival (OS) from the time of start of GVDex.

RESULTS

Forty-eight patients [median age: 24 years (5-63)] received GVDex [(median cycles:3(1-6)] in this period. Median time from diagnosis to the first relapse was 18.9 (2-119) months. Overall response rate [ORR = complete (CR)+partial (PR)] was 63%. Eleven (23%) patients developed febrile neutropenia. After a median follow-up of 20 months, the Kaplan-Meier estimates of patients alive and progression-free at 24 months were 60% and 49%, respectively.

CONCLUSIONS

The response rates with GVDex were comparable to those reported with GVDoxil when used as a first-line salvage regimen in relapsed/refractory HL. It was an effective regimen even in patients who failed 2 lines of therapy for HL.

Response-Adapted Treatment Strategies in Hodgkin Lymphoma Using PET Imaging

Hodgkin lymphoma, a B-cell malignancy, is most common in patients younger than 55 years. Between 70% and 90% are cured with standard approaches. The high cure rate and long-term survival resulted in a need to minimize therapy toxicity. Response-adapted approaches have been developed to de-escalate therapy in those likely to be cured and intensifying therapy in those not responding to initial treatment. FDG-PET after chemotherapy is highly predictive of outcome. Thus, FDG-PET has been incorporated into response-adapted treatments. Use of FDG-PET to guide treatment in Hodgkin lymphoma has been recommended. We summarize literature and discuss challenges and future directions.

Prognostic Utility of the IPS 3 Score for Predicting Outcomes in Advanced Hodgkin Lymphoma

BACKGROUND

The International Prognostic Scoring System (IPSS) consisting of 7 parameters (IPS7) has been the standard prognostic model used in advanced Hodgkin lymphoma (aHL). However, recent studies have questioned its discriminatory power. For retrospective analyses, its utility might be limited by missing parameters. A recent study has shown that the IPSS consisting of only 3 high-risk features (IPS3; stage IV, age 45 years or older, and hemoglobin <105 g/L) is a simple predictor of survival in aHL. However, there are limited data validating the IPS3.

PATIENTS AND METHODS

Outcomes of adults with aHL treated between 2001 and 2015 at a single center were retrospectively analyzed with data from medical records. The prognostic validity of various baseline parameters was assessed individually as well as in combination (IPS7 and IPS3 scores). The Kaplan-Meier method was used to describe the event-free survival (EFS) and overall survival (OS) and univariate (log rank) and multivariate (Cox regression) tests were performed to identify prognostic factors.

RESULTS

We identified 314 patients (median age, 32 [range, 18-60] years; male sex [n = 215; 68%]) treated during this period. IPS7 was available in 231 of 314 (73%) and IPS3 in all (100%) patients. Most (71%) were treated with 6 to 8 cycles of ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) and others received hybrid or cyclophosphamide, vincristine, procarbazine, prednisolone regimens, and 72 (23%) underwent interim positron emission tomography imaging with escalation to bleomycin, etoposide, adriamycin, cyclophosphamide, vincristine, procarbazine, prednisolone in 8 patients. After a median follow-up of 57 months (range, 1.3-167), the 5-year EFS and OS were 72% and 82%, respectively. IPS3 produced a wider separation of survival curves than IPS7 in univariate analysis. In multivariate analysis for EFS, IPS3 (scores of 2 or 3 vs. scores of 0 and 1; hazard ratio, 2.1; P = .004) was the only significant predictor. For OS, no factor emerged as significant.

CONCLUSION

The IPS3 is a simple 3-point system that is very useful for prediction of outcomes in aHL and might be particularly suited for retrospective data analysis where all components of the IPS7 might not be available.

Can Radiotherapy Be Omitted in Children With Hodgkin Lymphoma Who Achieve Metabolic Remission on Interim Positron Emission Tomography? Experience of a Tertiary Care Cancer Referral Center

PURPOSE

Treating pediatric Hodgkin lymphoma (HL) involves a delicate balance between cure and reducing late toxicity. Fluorodeoxyglucose positron emission tomography (PET) combined with computed tomography (CT) identifies patients with early response to chemotherapy, for whom radiotherapy may be avoided. The role of PET-CT in upfront risk stratification and response-adapted treatment is evaluated in this study.

METHODS

Patients with HL, who were younger than 18 years, were included. PET-CT was performed at baseline and after two cycles of chemotherapy. Patients were stratified into three risk groups: group 1 (stage I or II with no unfavorable features); group 2 (stage I or II with bulky disease/B symptoms); and group 3 (stage III/IV). A doxorubicin, bleomycin, vinblastine, dacarbazine-based regimen was used in early disease. A cyclophosphamide, vincristine, prednisolone, procarbazine, doxorubicin, bleomycin, vinblastine-based regimen was used in advanced disease.

RESULTS

Forty-nine patients were included. Fifteen (31%), seven (14%), and 27 (55%) patients were included in groups 1, 2, and 3, respectively. Among 36 patients who underwent staging by PET-CT at diagnosis, seven (19%) patients were upstaged and one (3%) patient was downstaged by PET compared with CT. On the basis of negative interim PET responses, 39 (80%) patients were treated without radiotherapy. The 3-year event-free survival for the entire cohort was 91% (± 5.2%) and overall survival was 100%.

CONCLUSION

PET-CT is an excellent stand-alone staging modality in HL. The omission of radiotherapy can be considered in patients who achieve metabolic remission on interim PET.

PET-adapted therapy for advanced Hodgkin lymphoma - systematic review

INTRODUCTION

Positron emission tomography-computed tomography (PET-CT) performed after two chemotherapy cycles (PET-2) has become an accepted prognostic tool in Hodgkin lymphoma (HL). We evaluated the effect of PET-adapted strategy on outcome in advanced stage HL.

METHODS

In August 2017, we searched electronic databases, conference proceedings and ongoing trials. We included all studies in which treatment modification for advanced HL was performed based on the results of the interim PET scan. The primary analysis included randomized controlled trials (RCTs). Outcomes were progression-free survival (PFS) and overall survival (OS).

RESULTS

We identified 13 studies (4 RCTs, 7 phase II and 2 retrospective studies), conducted between 1999 and 2014, including 6856 patients. Of the four RCTS: one used therapy escalation, one did de-escalation and two trials performed both. Outcomes were assessed at different time point between 2 and 5 years. Three RCTs for de-escalating therapy, obtained similar outcomes despite reducing therapy, with a 2-year PFS of 88-92% (6 escalated BEACOPP (EB) vs. 4 ABVD cycles), a 5-year PFS of 91-92% (6/8 EB vs. 4 EB cycles) and a 5-year PFS of 80-82% (6 ABVD vs. omitting bleomycin after two successful ABVD cycles). Two RCTs implemented escalation. The randomization was between adding rituximab or not. In both trials, it did not affect outcome, with a 4-year PFS of 68-69% (addition of rituximab to BEACOPP after 2 ABVD cycles) and 5-year PFS of 88-90% (addition of rituximab to EB after 2 EB cycles). Performing true randomization between PET-adapted and a standard ABVD control arm was not feasible, given historical data.

CONCLUSIONS

This systematic review of PET-adapted therapy, mainly based on RCTs, suggests that a change to the treatment paradigm is appropriate in advanced HL.

New Treatment Algorithms in Hodgkin Lymphoma: Too Much or Too Little?

Hodgkin lymphoma treatment continues to evolve as new means of assessing response to treatment, new appreciation of important risk factors, and more effective therapeutic agents become available. Treatment algorithms integrating functional imaging now provide the opportunity to modify therapy during its delivery, allowing adjustment of duration and intensity of chemotherapy and rationale identification of patients who may benefit from the addition of therapeutic irradiation. Novel agents, including the antibody drug conjugate brentuximab vedotin and checkpoint inhibitors such as nivolumab and pembrolizumab can improve the effectiveness of treatment while keeping toxicity within acceptable limits. Carefully designed clinical trials permit the identification of superior approaches in which efficacy is enhanced and toxicity minimized. Clinicians treating patients with Hodgkin lymphoma now have access to novel treatment approaches, which will require detailed assessment of each patient and careful discussion of the goals and risks of treatment at the time of planning primary treatment, again during delivery of that treatment as data indicating ongoing effectiveness become available, at the conclusion of initial intervention, and, when the need arises, at the time of recurrence of disease.

An evidence-based review on the value of interim FDG-PET in assessing response to therapy in lymphoma

Assessing response to therapy in lymphoma is important for determining patients' prognosis, guiding subsequent treatment, and may be used as an outcome measure of prognostic and therapeutic trials. Traditionally, computed tomography was the mainstay for response assessment and was predominantly performed at the end of treatment, whereas the most recent guidelines propose ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) for this purpose. However, the value of FDG-PET performed during treatment (interim FDG-PET) is still a topic of debate. The purpose of this scientific communication is to provide an evidence-based overview of the value of interim FDG-PET in patients with lymphoma. The article first describes the development of imaging-based response assessment in lymphoma, the rationale and limitations of using FDG-PET for this purpose, and continues with the evidence-based clinical utility of interim FDG-PET in three major lymphoma subtypes (Hodgkin lymphoma, diffuse large B-cell lymphoma, and follicular lymphoma), and finishes with conclusions and recommendations for standard care and future research.

Interim PET Response-adapted Strategy in Untreated Advanced Stage Hodgkin Lymphoma: Results of GOELAMS LH 2007 Phase 2 Multicentric Trial

BACKGROUND

Patients with advanced stage Hodgkin lymphoma still present unsatisfactory outcomes.

PATIENTS AND METHODS

The Groupe d'étude des Leucémies Aigues et des Maladies du Sang (GOELAMS) group conducted a prospective multicentric trial (NCT00920153) for advanced stage Hodgkin lymphoma to evaluate a positron emission tomography (PET)-adapted strategy. Patients received an intensive regimen (VABEM [vindesine, doxorubicin, carmustine, etoposide, and methylprednisolone]) in front-line and interim ^18FFDG-PET evaluation after 2 courses (PET-2). Patients with negative PET-2 findings received 1 additional course. Patients with positive PET-2 findings underwent early salvage therapy followed by high-dose therapy/autologous stem cell transplantation.

RESULTS

Fifty-one patients were included. The final complete remission rate was 88%. With a median follow up of 5.3 years, 5-year event-free survival and overall survival rates were 75.3% and 85.3%, respectively, for the whole cohort. Patients who were PET-2-negative had 5-year event-free survival and overall survival rates of, respectively, 77.8% and 88.2% versus 85.1% and 91.7% for patients who were PET-2-positive.

CONCLUSION

A PET-guided strategy with early salvage therapy and high-dose therapy/autologous stem cell transplantation for patients with interim PET-2-positive findings is safe and feasible and provide similar outcome as patients with a negative PET-2.

Frontline Therapy for Classical Hodgkin Lymphoma by Stage and Prognostic Factors

Hodgkin lymphoma is a highly curable malignancy in early and advanced stages. Most patients are diagnosed in their teens or twenties and are expected to live decades beyond their treatment. Therefore, the toxicity of treatment must be balanced with the goal of cure. Thus, treatment has been refined through prognostic models and positron emission tomography-computed tomography (PET-CT)-directed therapy. Stratification by prognostic models defines groups of patients with favorable characteristics who may be treated with less intensive therapy upfront, including fewer cycles of chemotherapy, lower doses of radiation, or omission of radiation altogether. Alternatively, high-risk patients may be assigned to a more aggressive initial approach. The modern use of interim PET-CT allows further tailoring of treatment by response.

How to Approach a Patient With Limited Stage Hodgkin Lymphoma Who Remains PET Positive at the End of Chemotherapy: Radiation Therapy?

The use of 18-F fluorodeoxyglucose (FDG) positron emission tomography (PET) with computed tomography has emerged as a crucial tool for response-adapted therapy in Hodgkin lymphoma (HL). Although more studies have focused on the predictive value of an interim or early PET obtained after 2 cycles of chemotherapy, there are indications that the end of therapy PET might even be more predictive of outcome. The optimal treatment of patients with limited stage HL who are PET-positive after chemotherapy is unknown. Here we review the prognostic significance of end of treatment PET in early stage HL, the role of consolidative radiotherapy in patients who have FDG-PET avidity at the end of chemotherapy, and discuss the place of salvage chemotherapy and autologous transplantation in these patients.

Controversies on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma

Hodgkin lymphoma, even in advanced-stage, is a highly curable malignancy, but treatment is associated with short-term toxicity and long-term side effects. Early predictive markers are required to identify those patients who do not require the full-length standard therapy (and thus qualify for therapy de-escalation) and those patients who will not be cured by standard therapy (and thus qualify for therapy escalation). Multiple trials have assessed the value of ¹⁸ F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) after a few cycles of chemotherapy (also known as 'interim FDG-PET') in predicting outcome in advanced-stage Hodgkin lymphoma. Furthermore, multiple interim FDG-PET-adapted trials, in which patients with positive interim FDG-PET scans are assigned to escalated therapies, and patients with negative interim FDG-PET scans are assigned to de-escalated therapies, have recently been published or are currently ongoing, with generally heterogeneous results. The present article reports the currently available evidence (and controversies) on the prognostic value of interim FDG-PET in advanced-stage Hodgkin lymphoma in patients with positive and negative interim FDG-PET findings following continuation of standard chemotherapy or escalated/de-escalated therapy.

Proportion of false-positive lesions at interim and end-of-treatment FDG-PET in lymphoma as determined by histology: Systematic review and meta-analysis

PURPOSE

To systematically review and meta-analyze the proportion of false-positive lesions at interim and end-of-treatment ¹⁸F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in lymphoma using biopsy as reference standard.

MATERIALS AND METHODS

Medline was searched for original studies. Methodological quality of included studies was evaluated, and results were meta-analytically summarized using random effects (in case of interstudy heterogeneity [I²≤50%]) or fixed effects (in case of no interstudy heterogeneity [I²>50%]).

RESULTS

Eleven studies, comprising 139 patients who underwent biopsy of an FDG-avid lesion during or after completion of antilymphoma treatment, were included. Overall methodological quality was moderate. The proportion of false-positive results among all biopsied FDG-avid lesions at PET performed during of after completion of treatment ranged between 7.7% and 90.5% (the vast majority was due to inflammatory changes), with a weighted summary proportion (random effects, I²=75.7%) of 55.7% (95% confidence interval [CI]: 32.6-76.6%). There were no available studies on interim FDG-PET in Hodgkin lymphoma. The pooled summary false-positive proportions were 83.0% (95% CI: 72.0%-90.2%) for interim FDG-PET in non-Hodgkin lymphoma (fixed effects, I²=27.7%), 23.1% (95% CI: 4.7%-64.5%) for end-of-treatment FDG-PET in Hodgkin lymphoma (random effects; I²=67.1%), and 31.5% (95% CI: 3.9%-83.9%) for end-of-treatment FDG-PET in non-Hodgkin lymphoma (random effects, I²=68.3%).

CONCLUSION

Both interim and end-of-treatment FDG-PET scans in patients with lymphoma suffer from a very high number of false-positive FDG-avid lesions. This finding, in combination with the previously reported high number of false-negative FGD-PET scans for residual disease detection, suggests that the role of interim and end-of-treatment FDG-PET should be reconsidered.

Treatment of advanced-stage Hodgkin lymphoma

There is now good evidence that the escalated BEACOPP regimen (bleomycin, etoposide, adriamycin, cyclophosphamide, vincristine, procarbazine, prednisone) is more effective in controlling advanced-stage Hodgkin lymphoma (HL) than the widely used ABVD regimen (adriamycin, bleomycin, vinblastine, dacarbazine), but the extra efficacy comes at the expense of both short- and long-term toxicity, and there is debate as to whether overall survival is affected. Baseline prognostic factors have proven of limited utility for determining which patients require more intensive therapy and recent studies have sought to use interim fluoro-deoxyglucose positron emission tomography (FDG-PET) evaluation as a means to guide the modulation of treatment, both upwards and downwards in intensity. These suggest that if treatment starts with ABVD then patients remaining PET-positive after 2 months can be salvaged with escalated BEACOPP in around 65% of cases, but those becoming PET-negative may still experience recurrences in 15%-20%, an event that is more common in those with more advanced disease at presentation. There are early data to suggest that starting with escalated BEACOPP may reduce the rate of recurrence after a negative interim PET to less than 10%. This may be an attractive approach for those with very high-risk features at presentation, but risks overtreating many patients if applied nonselectively. New regimens incorporating antibody-drug conjugates may shift the balance of efficacy and toxicity once again, and further studies are underway to evaluate this.

Risk-Adapted Treatment of Advanced Hodgkin Lymphoma With PET-CT

Although patients with advanced-stage classic Hodgkin lymphoma have excellent outcomes with contemporary therapy, the outcomes of patients with refractory disease is suboptimal. Identification of these high-risk patients at diagnosis is challenging as the differences in outcomes using clinical criteria are less marked using current modern therapy. Data suggest that an interim PET-CT may be a powerful tool in risk-stratifying patients. Retrospective studies show that a negative interim PET-CT after two to four cycles of ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) is predictive of favorable outcome independent of IPS score. Currently, there are several ongoing trials that aim to determine whether early-response assessment can be used to select patients who might benefit from modifications of subsequent therapy, either by intensifying or abbreviating regimens and/or omitting radiotherapy with promising early results. Longer follow-up is required to assess whether this strategy impacts overall survival (OS). Herein, we review the results of recent trials using interim PET-CT-based adaptive design in the treatment of advanced HL.