End-of-treatment but not interim PET scan predicts outcome in nonbulky limited-stage Hodgkin's lymphoma

Revisiting the predictive role of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography on treatment outcome in early-stage favorable Hodgkin lymphoma

In the present manuscript Gallamini et al. comment the results of three large, phase III, randomized clinical trials in early-stage favorable Hodgkin Lymphoma (HL), aimed at exploring the non-inferiority of ABVD chemotherapy alone compared to combined-modality treatment with ABVD and Involved Field/Node Radiotherapy (INRT). The authors also report the preliminary results of risk-stratification in the first 60 enrolled patients in the phase 2, prospective, international study RAFTING: RAdiotherapy Free Treatment IN Good-prognosis early-stage HL (National Trial Identifier 04866654). In this trial patients are stratified, before treatment onset, according to the risk of therapy failure in a single patient basis, taking into account non only the results of interim and End-of-Therapy PET, but also the value of new metrics extracted from the baseline PET/CT such as the Large Nodal Mass (LNM) and Total Metabolic Tumor Volume (TMTV). Treatment intensity, consisting in ABVD chemotherapy, INRT and Nivolumab maintenance, is modulated on the presence/absence of the above factors, in a personalized-medicine approach. The most frequently detected factors driving treatment intensity were LNM and TMTV, while the results of interim and end-of-treatment PET were also determinant, albeit in a lower percentage of cases.

PET/CT in Hodgkin Lymphoma: An Update

¹⁸F-FDG-PET/CT is now an integral part of the workup and management of patients with Hodgkin's lymphoma (HL). PET/CT is currently routinely performed for staging and for response assessment at the end of treatment. Interim PET/CT is typically performed after 1-4 of 6-8 chemo/chemoimmunotherapy cycles ± radiation for prognostication and potential treatment escalation or de-escalation early in the course of therapy, a concept known as response-or risk-adapted treatment. Quantitative PET is an area of growing interest. Metrics such as the standardized uptake value (SUV), metabolic tumor volume, total lesion glycolysis, and their changes with treatment are being investigated as more reproducible and, potentially, more accurate predictors of response and prognosis. Despite the progress made in standardizing the use of PET/CT in lymphoma, challenges remain, particularly with respect to its limited positive predictive value. This review highlights the most relevant applications of PET/CT in HL, its strengths and limitations, as well as recent efforts to implement PET/CT-based metrics as promising tools for precision medicine. Finally, the value of PET/CT for response assessment to immunotherapy is discussed.

Standardized classification schemes in reporting oncologic PET/CT

The imaging report is essential for the communication between physicians in patient care. The information it contains must be clear, concise with evidence-based conclusions and sufficient to support clinical decision-making. In recent years, several classification schemes and/or reporting guidelines for PET have been introduced. In this manuscript, we will review the classifications most frequently used in oncology for interpreting and reporting 18F-FDG PET imaging in lymphoma, multiple myeloma, melanoma and head and neck cancers, PSMA-ligand PET imaging for prostate cancer, and 68Ga-DOTA-peptide PET in neuroendocrine tumors (NET).

Thymus and activation-regulated chemokine (TARC) as treatment response marker for paediatric Hodgkin lymphoma: A pilot study

Classical Hodgkin lymphoma (cHL) is characterised by malignant Hodgkin Reed-Sternberg cells located in an inflammatory microenvironment. Blood biomarkers result from active cross-talk between malignant and non-malignant cells. One promising biomarker in adult patients with cHL is thymus and activation-regulated chemokine (TARC). We investigated TARC as marker for interim and end-of-treatment response in paediatric cHL. In this multicentre prospective study, TARC levels were measured among 99 paediatric patients with cHL before each cycle of chemotherapy and were linked with interim and end-of-treatment remission status. TARC levels were measured by enzyme-linked immunosorbent assay. At diagnosis, TARC levels were elevated in 96% of patients. Plasma TARC levels declined significantly after one cycle of chemotherapy (p < 0.01 vs. baseline) but did not differ at interim assessment by positron emission tomography (p = 0.31). In contrast, median plasma TARC at end of treatment was significantly higher in three patients with progressive disease compared to those in complete remission (1.226 vs. 90 pg/ml; p < 0.001). We demonstrate that, in paediatric patients, plasma TARC is a valuable response marker at end-of-treatment, but not at interim analysis after the first two chemotherapy cycles. Further research is necessary to investigate TARC as marker for long-term progression free survival.

Validation of Deauville Score for Response Evaluation in Hodgkin's Lymphoma

Context

Positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) for treatment monitoring in patients with lymphoma is one of the most well-developed clinical applications. Deauville five-point score (DS) is recommended for response assessment in international guidelines. DS gives the threshold for adequate or inadequate response to be adapted according to the clinical context or research question.

Aims

We aimed to validate DS in Hodgkin's lymphoma (HL) by retrospectively assigning this score to F-18 FDG PET-computed tomography (CT) studies done before 2016 and analyzing its concordance with the line of management. The secondary aim was to assess the reproducibility of DS in the interpretation of PET-CT scans.

Subjects and Methods

A total of 100 eligible consecutive patients underwent F-18 FDG PET-CT scans between January 2014 and December 2015. Their interim, end of treatment, and follow-up PET scans were retrospectively visually analyzed and assigned DS by three nuclear medicine physicians. Concordance was defined as agreement between the DS assigned and the line of treatment. Interobserver variability was calculated using weighted Kappa and presented with 95% confidence interval.

Results

Among 212 scans assigned DS, 165 scans showed agreement between the DS and line of treatment. Of these, 95.2% of scans scored DS 1-3 were kept on following or the same treatment plan was continued and patients did well. Among the scans that showed discordance, 24 scans scored DS 4/5 were continued on the same treatment regimen and the next assessment showed disease progression.

Conclusions

Our study confirmed that DS is a useful tool to aid in reporting F-18 FDG PET-CT in the management of HL with good positive and negative predictive values. This study also demonstrated good interobserver agreement.

Positron Emission Tomography Molecular Imaging for Phenotyping and Management of Lymphoma

Positron emission tomography (PET) represents molecular imaging for non-invasive phenotyping of physiological and biochemical processes in various oncological diseases. PET imaging with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) for glucose metabolism evaluation is the standard imaging modality for the clinical management of lymphoma. One of the ¹⁸F-FDG PET applications is the detection and pre-treatment staging of lymphoma, which is highly sensitive. ¹⁸F-FDG PET is also applied during treatment to evaluate the individual chemo-sensitivity and accordingly guide the response-adapted therapy. At the end of the therapy regiment, a negative PET scan is indicative of a good prognosis in patients with advanced Hodgkin's lymphoma and diffuse large B-cell lymphoma. Thus, adjuvant radiotherapy may be alleviated. Future PET studies using non-¹⁸F-FDG radiotracers, such as ⁶⁸Ga-labeled pentixafor (a cyclic pentapeptide that enables sensitive and high-contrast imaging of C-X-C motif chemokine receptor 4), ⁶⁸Ga-labeled fibroblast activation protein inhibitor (FAPI) that reflects the tumor microenvironment, and ⁸⁹Zr-labeled atezolizumab that targets the programmed cell death-ligand 1 (PD-L1), may complement ¹⁸F-FDG and offer essential tools to decode lymphoma phenotypes further and identify the mechanisms of lymphoma therapy.

The optimal use of PET/CT in the management of lymphoma patients

¹⁸F-fluoro-deoxyglucose positron emission tomography (PET)/computed tomography (CT) scans play an important role in the management of lymphoma patients. They are critical to accurately stage disease and assess its response to therapy. In addition, PET/CT scans enable precise target delineation for radiation therapy planning. In this review, we describe the use of PET/CT scans in lymphoma, with a focus on their role in staging disease, assessing response to therapy, predicting prognosis, and planning RT.

Ability of final PET/CT to predict response to first-line treatment in real patients with classical Hodgkin lymphoma

Up to 25% of patients with classical Hodgkin lymphoma (cHL) and a negative interim PET/CT will progress. Unfortunately, there are few published studies on the predictive value of PET/CT performed after finishing treatment. The objective of our study was to assess the role of the final PET/CT (fPET/CT) in predicting progression in a retrospective series of patients treated in the last 10 years with a homogeneous protocol (ABVD + / - radiotherapy). We reviewed a cohort of 227 patients with newly diagnosed cHL. fPET/CT was performed on 212 patients (93%). In patients with a positive fPET, progression-free survival at 60 months was 17% (94% if fPET was negative, p = 0.000). The positive and negative predictive values for the fPET were 76% and 94%, respectively (Fisher's exact test, p = 0.000). In the subgroup of patients with advanced-stage cHL, progression-free survival at 60 months was 91% with negative fPET and 0% with positive fPET (p = 0.000). However, fPET was negative in 19 of the 29 patients with a positive interim PET/CT (only 2 showed progression). In conclusion, fPET is a useful tool to predict treatment failure in patients with newly diagnosed cHL, especially advanced-stage disease.

Intratumor Heterogeneity Assessed by 18F-FDG PET/CT Predicts Treatment Response and Survival Outcomes in Patients with Hodgkin Lymphoma

RATIONALE AND OBJECTIVES

Radiomic analysis of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) images enables the extraction of quantitative information of intratumour heterogeneity. This study investigated whether the baseline ¹⁸F-FDG PET/CT radiomics can predict treatment response and survival outcomes in patients with Hodgkin lymphoma (HL).

MATERIALS AND METHODS

Thirty-five patients diagnosed with HL who underwent ¹⁸F-FDG PET/CT scans before and during chemotherapy were retrospectively enrolled in this investigation. For each patient, we extracted 709 radiomic features from pretreatment PET/CT images. Clinical variables (age, gender, B symptoms, bulky tumor, and disease stage) and radiomic signatures (intensity, texture, and wavelet) were analyzed according to response to therapy, progression-free survival (PFS), and overall survival (OS). Receiver operating characteristic curve, logistic regression, and Cox proportional hazards model were used to examine potential predictive and prognostic factors.

RESULTS

High-intensity run emphasis (HIR) of PET and run-length nonuniformity (RLNU) of CT extracted from gray-level run-length matrix (GLRM) in high-frequency wavelets were independent predictive factors for the treatment response (odds ratio [OR] = 36.4, p = 0.014; OR = 30.4, p = 0.020). Intensity nonuniformity (INU) of PET and wavelet short run emphasis (SRE) of CT from GLRM and Ann Arbor stage were independently related to PFS (hazard ratio [HR] = 9.29, p = 0.023; HR = 18.40, p = 0.012; HR = 7.46, p = 0.049). Zone-size nonuniformity (ZSNU) of PET from gray-level size zone matrix (GLSZM) was independently associated with OS (HR = 41.02, p = 0.001). Based on these factors, a prognostic stratification model was devised for the risk stratification of patients. The proposed model allowed the identification of four risk groups for PFS and OS (p < 0.001 and p < 0.001).

CONCLUSION

HIR_{_}GLRM_PET and RLNU_{_}GLRM_CT in high-frequency wavelets serve as independent predictive factors for treatment response. ZSNU_{_}GLSZM_PET, INU_{_}GLRM_PET, and wavelet SRE_{_}GLRM_CT serve as independent prognostic factors for survival outcomes. The present study proposes a prognostic stratification model that may be clinically beneficial in guiding risk-adapted treatment strategies for patients with HL.

Update on Hodgkin lymphoma from a radiologist's perspective

Recent advances in the management of Hodgkin lymphoma, due to new staging and response assessment systems as well as new therapies, have redefined the role of imaging for this disease. The purpose of this article is to provide radiologists with an update on the current role of imaging in Hodgkin lymphoma from diagnosis to assessment of treatment response, in view of the new staging and response assessment system and current treatment strategies.

Interim PET-results for prognosis in adults with Hodgkin lymphoma: a systematic review and meta-analysis of prognostic factor studies

BACKGROUND

Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET during chemotherapy has been posited as a prognostic factor in individuals with HL to distinguish between those with a poor prognosis and those with a better prognosis. This distinction is important to inform decision-making on the clinical pathway of individuals with HL.

OBJECTIVES

To determine whether in previously untreated adults with HL receiving first-line therapy, interim PET scan results can distinguish between those with a poor prognosis and those with a better prognosis, and thereby predict survival outcomes in each group.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and conference proceedings up until April 2019. We also searched one trial registry (ClinicalTrials.gov).

SELECTION CRITERIA

We included retrospective and prospective studies evaluating interim PET scans in a minimum of 10 individuals with HL (all stages) undergoing first-line therapy. Interim PET was defined as conducted during therapy (after one, two, three or four treatment cycles). The minimum follow-up period was at least 12 months. We excluded studies if the trial design allowed treatment modification based on the interim PET scan results.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form according to the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Two teams of two review authors independently screened the studies, extracted data on overall survival (OS), progression-free survival (PFS) and PET-associated adverse events (AEs), assessed risk of bias (per outcome) according to the Quality in Prognosis Studies (QUIPS) tool, and assessed the certainty of the evidence (GRADE). We contacted investigators to obtain missing information and data.

MAIN RESULTS

Our literature search yielded 11,277 results. In total, we included 23 studies (99 references) with 7335 newly-diagnosed individuals with classic HL (all stages). Participants in 16 studies underwent (interim) PET combined with computed tomography (PET-CT), compared to PET only in the remaining seven studies. The standard chemotherapy regimen included ABVD (16) studies, compared to BEACOPP or other regimens (seven studies). Most studies (N = 21) conducted interim PET scans after two cycles (PET2) of chemotherapy, although PET1, PET3 and PET4 were also reported in some studies. In the meta-analyses, we used PET2 data if available as we wanted to ensure homogeneity between studies. In most studies interim PET scan results were evaluated according to the Deauville 5-point scale (N = 12). Eight studies were not included in meta-analyses due to missing information and/or data; results were reported narratively. For the remaining studies, we pooled the unadjusted hazard ratio (HR). The timing of the outcome measurement was after two or three years (the median follow-up time ranged from 22 to 65 months) in the pooled studies. Eight studies explored the independent prognostic ability of interim PET by adjusting for other established prognostic factors (e.g. disease stage, B symptoms). We did not pool the results because the multivariable analyses adjusted for a different set of factors in each study. Overall survival Twelve (out of 23) studies reported OS. Six of these were assessed as low risk of bias in all of the first four domains of QUIPS (study participation, study attrition, prognostic factor measurement and outcome measurement). The other six studies were assessed as unclear, moderate or high risk of bias in at least one of these four domains. Four studies were assessed as low risk, and eight studies as high risk of bias for the domain other prognostic factors (covariates). Nine studies were assessed as low risk, and three studies as high risk of bias for the domain 'statistical analysis and reporting'. We pooled nine studies with 1802 participants. Participants with HL who have a negative interim PET scan result probably have a large advantage in OS compared to those with a positive interim PET scan result (unadjusted HR 5.09, 95% confidence interval (CI) 2.64 to 9.81, I² = 44%, moderate-certainty evidence). In absolute values, this means that 900 out of 1000 participants with a negative interim PET scan result will probably survive longer than three years compared to 585 (95% CI 356 to 757) out of 1000 participants with a positive result. Adjusted results from two studies also indicate an independent prognostic value of interim PET scan results (moderate-certainty evidence). Progression-free survival Twenty-one studies reported PFS. Eleven out of 21 were assessed as low risk of bias in the first four domains. The remaining were assessed as unclear, moderate or high risk of bias in at least one of the four domains. Eleven studies were assessed as low risk, and ten studies as high risk of bias for the domain other prognostic factors (covariates). Eight studies were assessed as high risk, thirteen as low risk of bias for statistical analysis and reporting. We pooled 14 studies with 2079 participants. Participants who have a negative interim PET scan result may have an advantage in PFS compared to those with a positive interim PET scan result, but the evidence is very uncertain (unadjusted HR 4.90, 95% CI 3.47 to 6.90, I² = 45%, very low-certainty evidence). This means that 850 out of 1000 participants with a negative interim PET scan result may be progression-free longer than three years compared to 451 (95% CI 326 to 569) out of 1000 participants with a positive result. Adjusted results (not pooled) from eight studies also indicate that there may be an independent prognostic value of interim PET scan results (low-certainty evidence). PET-associated adverse events No study measured PET-associated AEs.

AUTHORS' CONCLUSIONS

This review provides moderate-certainty evidence that interim PET scan results predict OS, and very low-certainty evidence that interim PET scan results predict progression-free survival in treated individuals with HL. This evidence is primarily based on unadjusted data. More studies are needed to test the adjusted prognostic ability of interim PET against established prognostic factors.

Clinical characteristics of interim-PET negative patients with a positive end PET from the prospective HD08-01 FIL study

FDG-positron emission tomography (PET) performed early during therapy in advanced Hodgkin lymphoma patients has been confirmed as being important for progression-free survival. A group of patients with a negative interim-PET (i-PET) showed a positive end induction PET (e-PET). The aim of this study was to evaluate the clinical characteristics of patients with a positive e-PET as a secondary end point of the HD0801 study. A total of 519 patients with advanced-stage de novo Hodgkin lymphoma received initial treatment and underwent an i-PET. Patients with negative results continued the standard treatment. i-PET negative patients were then evaluated for response with an e-PET and those patients found to have a positive one were also then given a salvage therapy. Among 409 i-PET negative, 16 interrupted the therapy, 393 patients were evaluated with an e-PET, and 39 were positive. Sixteen out of 39 underwent a diagnostic biopsy and 15 were confirmed as HD. Seventeen out of 39 e-PET were reviewed according to the Deauville Score and, in sixteen, it was confirmed positive (10 DS 5, 6 DS 4). With the exception of high LDH value at diagnosis (p = 0.01; HR 95% CI 1.18-4.89), no clinical characteristics were significantly different in comparison with e-PET negative patients. Positive e-PET after a negative i-PET has a worse outcome when compared with i-PET positive patients salvaged with therapy intensification. It was not possible to identify clinical characteristics associated with a positive e-PET.

Interim PET-results for prognosis in adults with Hodgkin lymphoma: a systematic review and meta-analysis of prognostic factor studies

BACKGROUND

Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET during chemotherapy has been posited as a prognostic factor in individuals with HL to distinguish between those with a poor prognosis and those with a better prognosis. This distinction is important to inform decision-making on the clinical pathway of individuals with HL.

OBJECTIVES

To determine whether in previously untreated adults with HL receiving first-line therapy, interim PET scan results can distinguish between those with a poor prognosis and those with a better prognosis, and thereby predict survival outcomes in each group.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and conference proceedings up until April 2019. We also searched one trial registry (ClinicalTrials.gov).

SELECTION CRITERIA

We included retrospective and prospective studies evaluating interim PET scans in a minimum of 10 individuals with HL (all stages) undergoing first-line therapy. Interim PET was defined as conducted during therapy (after one, two, three or four treatment cycles). The minimum follow-up period was at least 12 months. We excluded studies if the trial design allowed treatment modification based on the interim PET scan results.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form according to the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Two teams of two review authors independently screened the studies, extracted data on overall survival (OS), progression-free survival (PFS) and PET-associated adverse events (AEs), assessed risk of bias (per outcome) according to the Quality in Prognosis Studies (QUIPS) tool, and assessed the certainty of the evidence (GRADE). We contacted investigators to obtain missing information and data.

MAIN RESULTS

Our literature search yielded 11,277 results. In total, we included 23 studies (99 references) with 7335 newly-diagnosed individuals with classic HL (all stages).Participants in 16 studies underwent (interim) PET combined with computed tomography (PET-CT), compared to PET only in the remaining seven studies. The standard chemotherapy regimen included ABVD (16) studies, compared to BEACOPP or other regimens (seven studies). Most studies (N = 21) conducted interim PET scans after two cycles (PET2) of chemotherapy, although PET1, PET3 and PET4 were also reported in some studies. In the meta-analyses, we used PET2 data if available as we wanted to ensure homogeneity between studies. In most studies interim PET scan results were evaluated according to the Deauville 5-point scale (N = 12).Eight studies were not included in meta-analyses due to missing information and/or data; results were reported narratively. For the remaining studies, we pooled the unadjusted hazard ratio (HR). The timing of the outcome measurement was after two or three years (the median follow-up time ranged from 22 to 65 months) in the pooled studies.Eight studies explored the independent prognostic ability of interim PET by adjusting for other established prognostic factors (e.g. disease stage, B symptoms). We did not pool the results because the multivariable analyses adjusted for a different set of factors in each study.Overall survivalTwelve (out of 23) studies reported OS. Six of these were assessed as low risk of bias in all of the first four domains of QUIPS (study participation, study attrition, prognostic factor measurement and outcome measurement). The other six studies were assessed as unclear, moderate or high risk of bias in at least one of these four domains. Nine studies were assessed as high risk, and three studies as moderate risk of bias for the domain study confounding. Eight studies were assessed as low risk, and four studies as high risk of bias for the domain statistical analysis and reporting.We pooled nine studies with 1802 participants. Participants with HL who have a negative interim PET scan result probably have a large advantage in OS compared to those with a positive interim PET scan result (unadjusted HR 5.09, 95% confidence interval (CI) 2.64 to 9.81, I² = 44%, moderate-certainty evidence). In absolute values, this means that 900 out of 1000 participants with a negative interim PET scan result will probably survive longer than three years compared to 585 (95% CI 356 to 757) out of 1000 participants with a positive result.Adjusted results from two studies also indicate an independent prognostic value of interim PET scan results (moderate-certainty evidence).Progression-free survival Twenty-one studies reported PFS. Eleven out of 21 were assessed as low risk of bias in the first four domains. The remaining were assessed as unclear, moderate or high risk of bias in at least one of the four domains. Eleven studies were assessed as high risk, nine studies as moderate risk and one study as low risk of bias for study confounding. Eight studies were assessed as high risk, three as moderate risk and nine as low risk of bias for statistical analysis and reporting.We pooled 14 studies with 2079 participants. Participants who have a negative interim PET scan result may have an advantage in PFS compared to those with a positive interim PET scan result, but the evidence is very uncertain (unadjusted HR 4.90, 95% CI 3.47 to 6.90, I² = 45%, very low-certainty evidence). This means that 850 out of 1000 participants with a negative interim PET scan result may be progression-free longer than three years compared to 451 (95% CI 326 to 569) out of 1000 participants with a positive result.Adjusted results (not pooled) from eight studies also indicate that there may be an independent prognostic value of interim PET scan results (low-certainty evidence).PET-associated adverse eventsNo study measured PET-associated AEs.

AUTHORS' CONCLUSIONS

This review provides moderate-certainty evidence that interim PET scan results predict OS, and very low-certainty evidence that interim PET scan results predict progression-free survival in treated individuals with HL. This evidence is primarily based on unadjusted data. More studies are needed to test the adjusted prognostic ability of interim PET against established prognostic factors.

The role of PET/CT in the modern treatment of Hodgkin lymphoma

Classical Hodgkin Lymphoma is distinguished from other lymphomas by its peculiar biology and heterogeneous chemosensitivity. Most of the patients respond to the standard first-line treatment and are cured, however, in selected cases, the disease relapses or remains primarily refractory. Among predictive/prognostic factors ¹⁸FDG positron emission tomography (PET), fully integrated with computed tomography (PET/CT) proved to be extremely useful in identifying patients with poor prognosis at the time of diagnosis, during and at the end of treatment. The aim of this review is to present the current role of PET/CT in cHL at staging, interim and end of therapy assessment and its ability to guide treatment with a response- and risk-adapted strategy in clinical practice. Finally, quantitative PET measurement and the concurrent use of PET with selected biomarkers are discussed.

Brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine for nonbulky limited-stage classical Hodgkin lymphoma

Doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) with or without radiation is standard therapy for limited-stage Hodgkin lymphoma (HL) but carries risks of bleomycin-induced lung injury and radiation toxicity. Brentuximab vedotin is highly active in relapsed HL and was recently approved with doxorubicin, vinblastine, and dacarbazine (AVD) for previously untreated stage III/IV HL. We evaluated brentuximab-AVD for nonbulky stage I/II HL in a multicenter phase 2 study. Patients received a lead-in cycle of brentuximab vedotin monotherapy on days 1 and 15, followed by an exploratory positron emission tomography/computed tomography scan. Patients then received brentuximab-AVD for 4 to 6 cycles based on interim positron emission tomography/computed tomography scanning after cycle 2. Thirty-four patients were enrolled with a median age of 36 years (range, 20-75 years). Risk was early favorable in 62% and unfavorable in 38%. The best complete response rate was 100%. At a median follow-up of 38 months, the progression-free survival and overall survival were 94% and 97%, respectively. The most common adverse events were peripheral sensory neuropathy (79%), neutropenia (76%), fatigue (74%), and nausea (71%). The most common grade 3/4 toxicities were neutropenia (62%), febrile neutropenia (35%), and peripheral sensory neuropathy (24%). One elderly patient died of neutropenic sepsis in the first brentuximab-AVD cycle. Brentuximab dose reductions were required in 38% of patients, most for peripheral neuropathy. In conclusion, brentuximab-AVD without bleomycin or radiation produced a high complete response rate, with most patients requiring only 4 total cycles of therapy. Because toxicity was higher than would be expected from AVD alone, this method may not be appropriate for early-stage patients with a highly favorable prognosis. This trial was registered at www.clinicaltrials.gov as #NCT01534078.

18F-FDG PET-CT in paediatric oncology: established and emerging applications

Accurate staging and response assessment is vital in the management of childhood malignancies. Fluorine-18 fluorodeoxyglucose positron emission tomography/CT (FDG PET-CT) provides complimentary anatomical and functional information. Oncological applications of FDG PET-CT are not as well-established within the paediatric population compared to adults. This article will comprehensively review established oncological PET-CT applications in paediatric oncology and provide an overview of emerging and future developments in this domain.

Role of FDG PET-CT in the treatment management of Hodgkin lymphoma

Fluorodeoxyglucose (FDG) positons emission tomography (PET)-computed tomography (CT) is used in many ways at baseline and during the treatment of patients with Hodgkin lymphoma. Many properties of the technique are used in the different steps of patient's management. Initial staging with PET-CT is more accurate than conventional imaging and PET-CT also became the gold standard imaging at the end of treatment with a negative PET-CT mandatory for reaching a complete remission. Early assessment of response by PET-CT is one of the most powerful prognostic factors for progression-free survival of patients with localized and advanced stages and allows guiding treatment. Conversely, previous studies showed that there is no role of FDG PET-CT for the patient's follow-up.

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.

Brentuximab Vedotin with Chemotherapy for Stage III or IV Hodgkin's Lymphoma

BACKGROUND

Brentuximab vedotin is an anti-CD30 antibody-drug conjugate that has been approved for relapsed and refractory Hodgkin's lymphoma.

METHODS

We conducted an open-label, multicenter, randomized phase 3 trial involving patients with previously untreated stage III or IV classic Hodgkin's lymphoma, in which 664 were assigned to receive brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine (A+AVD) and 670 were assigned to receive doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). The primary end point was modified progression-free survival (the time to progression, death, or noncomplete response and use of subsequent anticancer therapy) as adjudicated by an independent review committee. The key secondary end point was overall survival.

RESULTS

At a median follow-up of 24.6 months, 2-year modified progression-free survival rates in the A+AVD and ABVD groups were 82.1% (95% confidence interval [CI], 78.8 to 85.0) and 77.2% (95% CI, 73.7 to 80.4), respectively, a difference of 4.9 percentage points (hazard ratio for an event of progression, death, or modified progression, 0.77; 95% CI, 0.60 to 0.98; P=0.04). There were 28 deaths with A+AVD and 39 with ABVD (hazard ratio for interim overall survival, 0.73 [95% CI, 0.45 to 1.18]; P=0.20) [corrected]. All secondary efficacy end points trended in favor of A+AVD. Neutropenia occurred in 58% of the patients receiving A+AVD and in 45% of those receiving ABVD; in the A+AVD group, the rate of febrile neutropenia was lower among the 83 patients who received primary prophylaxis with granulocyte colony-stimulating factor than among those who did not (11% vs. 21%). Peripheral neuropathy occurred in 67% of patients in the A+AVD group and in 43% of patients in the ABVD group; 67% of patients in the A+AVD group who had peripheral neuropathy had resolution or improvement at the last follow-up visit. Pulmonary toxicity of grade 3 or higher was reported in less than 1% of patients receiving A+AVD and in 3% of those receiving ABVD. Among the deaths that occurred during treatment, 7 of 9 in the A+AVD group were associated with neutropenia and 11 of 13 in the ABVD group were associated with pulmonary-related toxicity.

CONCLUSIONS

A+AVD had superior efficacy to ABVD in the treatment of patients with advanced-stage Hodgkin's lymphoma, with a 4.9 percentage-point lower combined risk of progression, death, or noncomplete response and use of subsequent anticancer therapy at 2 years. (Funded by Millennium Pharmaceuticals and Seattle Genetics; ECHELON-1 ClinicalTrials.gov number, NCT01712490 ; EudraCT number, 2011-005450-60 .).

PET-CT in Staging, Response Evaluation, and Surveillance of Lymphoma

OPINION STATEMENT

Lymphoma represents a broad spectrum of diseases with diverse biology, clinical behavior, and imaging features. Functional imaging with 18-F-fluorodeoxyglucose (FDG)-positron emission tomography combined with computed tomography (PET-CT) is widely recognized as the most sensitive and specific imaging modality for patients with lymphoma and is used as part of staging, response evaluation, and surveillance in patients with Hodgkin (HL) and non-Hodgkin lymphoma (NHL). Recent efforts at standardizing the conduct and consensus interpretation of PET-CT have facilitated its use in patients on clinical studies and beyond. The role of PET-CT has been affirmed in some clinical situations, such as staging and end-of-treatment evaluation in Hodgkin lymphoma and diffuse large B cell lymphoma (DLBCL), and in the evaluation of aggressive transformation of an indolent lymphoma. However, the role of functional imaging in other histologies and clinical settings is not as clear given the higher rate of false positive results and the costs inherent to PET-CT. There is little evidence to suggest its utility or impact on outcome in most indolent lymphomas, or in the setting of post-treatment surveillance. In addition, there remains controversy about the value of PET-CT in early response assessment during active therapy, particularly in DLBCL. This review will evaluate the evidence surrounding the role of PET-CT in staging, response evaluation and surveillance of Hodgkin and non-Hodgkin lymphoma.

Early-stage Hodgkin lymphoma outcomes after combined modality therapy according to the post-chemotherapy 5-point score: can residual pet-positive disease be cured with radiotherapy alone?

Early-stage classical Hodgkin lymphoma (HL) patients are evaluated by an end-of-chemotherapy positron emission tomography-computed tomography (eoc-PET-CT) after doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) and before radiation therapy (RT). We determined freedom from progression (FFP) in patients treated with ABVD and RT according to the eoc-PET-CT 5-point score (5PS). Secondarily, we assessed whether patients with a positive eoc-PET-CT (5PS of 4-5) can be cured with RT alone. The cohort comprised 174 patients treated for stage I-II HL with ABVD and RT alone. ABVD was given with a median of four cycles and RT with a median dose of 30·6 Gy. Five-year FFP was 97%. Five-year FFP was 100% (0 relapses/98 patients) for patients with a 5PS of 1-2, 97% (2/65) for a 5PS of 3, 83% (1/8) for a 5PS of 4, and 67% (1/3) for a 5PS of 5 (P < 0·001). Patients with positive eoc-PET-CT scans who were selected for salvage RT alone had experienced a very good partial response to ABVD. Risk factors for recurrence in this subgroup included a small reduction in tumour size and a 'bounce' in ≥1 PET-CT parameter (reduction then rise from interim to final scan). Thus, a positive eoc-PET-CT is associated with inferior FFP; however, appropriately selected patients can be cured with RT alone.

FDG PET for therapy monitoring in Hodgkin and non-Hodgkin lymphomas

PET using 18F-FDG for treatment monitoring in patients with lymphoma is one of the most well-developed clinical applications. PET/CT is nowadays used during treatment to assess chemosensitivity, with response-adapted therapy given according to 'interim' PET in clinical practice to adults and children with Hodgkin lymphoma. PET is also used to assess remission from disease and to predict prognosis in the pretransplant setting. Mature data have been reported for the common subtypes of aggressive B-cell lymphomas, with more recent data also supporting the use of PET for response assessment in T-cell lymphomas. The Deauville five-point scale incorporating the Deauville criteria (DC) is recommended for response assessment in international guidelines. FDG uptake is graded in relation to the reference regions of normal mediastinum and liver. The DC have been validated in most lymphoma subtypes. The DC permit the threshold for adequate or inadequate response to be adapted according to the clinical context or research question. It is important for PET readers to understand how the DC have been applied in response-adapted trials for correct interpretation and discussion with the multidisciplinary team. Quantitative methods to perform PET in standardized ways have also been developed which may further improve response assessment including a quantitative extension to the DC (qPET). This may have advantages in providing a continuous scale to refine the threshold for adequate/inadequate response in specific clinical situations or treatment optimization in trials. qPET is also less observer-dependent and limits the problem of optical misinterpretation due to the influence of background activity.

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.

The role of FDG-PET in Hodgkin lymphoma

18-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) is currently the most valuable imaging technique in Hodgkin lymphoma. Since its first use in lymphomas in the 1990s, it has become the gold standard in the staging and end-of-treatment remission assessment in patients with Hodgkin lymphoma. The possibility of using early (interim) PET during first-line therapy to evaluate chemosensitivity and thus personalize treatment at this stage holds great promise, and much attention is now being directed toward this goal. With high probability, it is believed that in the near future, the result of interim PET-CT would serve as a compass to optimize treatment. Also the role of PET in pre-transplant assessment is currently evolving. Much controversy surrounds the possibility of detecting relapse after completed treatment with the use of PET in surveillance in the absence of symptoms suggestive of recurrence and the results of published studies are rather discouraging because of low positive predictive value. This review presents current knowledge about the role of 18-FDG-PET/CT imaging at each point of management of patients with Hodgkin lymphoma.

Pediatric Hodgkin Lymphoma: Predictive value of interim 18F-FDG PET/CT in therapy response assessment

We investigated the prognostic value of interim F-FDG PET/CT (PET-2) in pediatric Hodgkin lymphoma (pHL), evaluating both visual and semiquantitative analysis.Thirty pHL patients (age ≤16) underwent serial F-FDG PET/CT: at baseline (PET-0), after 2 cycles of chemotherapy (PET-2) and at the end of first-line chemotherapy (PET-T). PET response assessment was carried out visually according to the Deauville Score (DS), as well as semiquantitatively by using the semiquantitative parameters reduction from PET-0 to PET-2 (ΔΣSUVmax0-2, ΔΣSUVmean0-2). Final clinical response assessment (outcome) at the end of first-line chemotherapy was the criterion standard, considering patients as responders (R) or nonresponders (NR). Disease status was followed identifying patients with absence or relapsed/progression disease (mean follow-up: 24 months, range 3-78).Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of visual and semiquantitative assessment were calculated; furthermore, Fisher exact test was performed to evaluate the association between both visual and semiquantitative assessment and outcome at the end of the first-line chemotherapy. The prognostic capability of PET-2 semiquantitative parameters was calculated by ROC analysis and expressed as area under curve (AUC). Finally, progression-free survival (PFS) was analyzed according to PET-2 results based on the 5-point scale and semiquantitative criteria, using the Kaplan-Meier method.Based on the outcome at the end of first-line chemotherapy, 5 of 30 patients were NR, the remnant 25 of 30 were R. Sensitivity, specificity, PPV, NPV, and accuracy of visual analysis were 60%,72%,30%,90%,70%; conversely, sensitivity, specificity, PPV, NPV, and accuracy of semiquantitative assessment were 80%, 92%, 66.7%, 95.8%, 90%. The highest AUC resulted for ΔΣSUVmax0-2 (0.836; cut-off <12.5; sensitivity 80%; specificity 91%). The association between ΔΣSUVmax0-2 and outcome at the end of first-line chemotherapy resulted to have a strong statistical significance (P = 0.0026). Both methods demonstrated to influence PFS, even if the semiquantitative assessment allowed a more accurate identification of patients with a high risk of treatment failure (P = 0.005).Our preliminary results showed that PET-2 visual assessment, by using Deauville criteria, can be improved by using the semiquantitative analysis. The SUV max reduction (ΔΣSUVmax0-2) evaluation might provide a support for the interpretation of intermediate scores, predicting with good confidence those patients who will have a poor outcome and require alternative therapies.

Utility of baseline, interim and end-of-treatment 18F-FDG PET/CT in extranodal natural killer/T-cell lymphoma patients treated with L-asparaginase/pegaspargase

Positron emission tomography-computed tomography (PET/CT) is widely used for initial staging and monitoring treatment responses in Hodgkin and diffuse large B-cell lymphoma. However, its prognostic value in extranodal natural killer (NK)/T-cell lymphoma (ENKL) remains unclear. Here, we conducted a retrospective study to determine the impact of PET/CT in ENKL. Fifty-two patients newly diagnosed with ENKL were enrolled. Baseline maximum standardized uptake values (SUVmax), whole-body metabolic tumor volume (WBMTV) and whole-body total lesion glycolysis (WBTLG) were recorded. Additionally, interim PET/CT (I-PET) and end-of-treatment PET/CT (E-PET) results were scored using a 5-point scale. Patients were divided into groups using baseline parameter cut-off values; significant differences were found in overall survival (OS) and progression-free survival (PFS) between the high and low WBMTV and WBTLG groups and in OS between the two SUVmax groups. Positive I-PET and E-PET results predicted inferior PFS and OS. A multivariate analysis showed that baseline WBTLG, I-PET and E-PET results were associated with PFS and OS, and baseline SUVmax was an independent predictor of OS. Thus, baseline WBTLG, I-PET and E-PET results are good predictors of PFS and OS in ENKL patients who received L-asparaginase/pegaspargase in their first-line treatment, and baseline SUVmax is a valuable tool for assessing OS.

PET/CT in the Evaluation of Relapsed or Refractory Hodgkin Lymphoma

18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) has been the most important advance in the assessment of Hodgkin lymphoma (HL) since the introduction of computed tomography (CT). In the frontline management of HL, FDG-PET combined with low-dose CT has emerged as the modality of choice for staging and treatment response assessment. Substantial data have accumulated over the past several years supporting the use of PET/CT in the evaluation and management of relapsed or refractory HL, as well. In this article, we review the role of PET/CT after the frontline treatment of HL, as well as the prognostic utility of PET/CT before autologous and allogeneic stem cell transplantation. We also review the use of PET/CT as a part of response-adapted treatment strategies in relapsed or refractory HL and implications for current and future clinical practice.

Hodgkin lymphoma: a negative interim-PET cannot circumvent the need for end-of-treatment-PET evaluation

We examined the outcome of a cohort of patients with Hodgkin lymphoma (HL) in order to assess if fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) at the end of treatment (end-PET) can be omitted when the interim PET (int-PET) is negative. Seventy-six ABVD(adriamycin, bleomycin, vinblastine, dacarbazine)-treated patients were retrospectively included. No change in treatment was made on the basis of int-PET results. Suspicious foci on end-PET received biopsy confirmation whenever possible. Median follow-up was 58·9 months. Uptake on int-PET higher than liver (scores 4-5) was rated positive according to the Lugano classification, while a positive end-PET corresponded to scores 3, 4 and 5. Fifteen patients had treatment failure. Sensitivity, specificity, positive predictive value (PPV), negative predictive value and accuracy of int-PET were 46·7%, 85·2%, 43·8%, 86·7% and 77·6%, respectively. For end-PET the figures were: 80%, 93·4%, 75%, 95% and 90·8%. Eight patients with negative int-PET had treatment failure; six of them were identified as non-responders with end-PET. The 5-year progression-free survival (PFS) was 87% for patients with negative int-PET versus 56% with positive int-PET. The 5-year PFS was 96% with negative end-PET versus 23% with positive end-PET. The prognostic information from int-PET as regards PFS (log-rank test P = 0·0048) was lower than that provided by end-PET (P < 0·0001). Int-PET predicted only half of the failures. When used in clinical routine, a negative int-PET study cannot obviate the need for end-PET examination.

Hodgkin Lymphoma: the Changing Role of Radiation Therapy in Early-Stage Disease—the Role of Functional Imaging

Early-stage classical Hodgkin lymphoma (CHL) is a highly curable malignancy. Historically, extended-field radiotherapy (EFRT) alone showed excellent cure rates, but the risk of radiotherapy (RT)-associated toxicities led to combined modality therapy (CMT) replacing RT alone. RT has subsequently evolved further with significant reductions of dose and field size, and is currently restricted to involved sites only (ISRT). Contemporary CMT yields cure rates in excess of 85%, and most studies do not have adequate follow-up required to evaluate the risk reduction in late effects. In an effort to avoid RT altogether, response-adapted treatment approaches utilizing results of interim [(18)F]fluorodeoxyglucose (FDG) positron emission tomography with fused computed tomography (PET/CT) imaging have been studied. Results from two studies in favorable-risk (UK RAPID and EORTC H10F) and one in unfavorable-risk patients (EORTC H10U) suggest that omission of RT in patients with a negative interim PET/CT response (Deauville score ≤2) yields slightly inferior progression-free survival (PFS) compared to conventional CMT, but with no difference in overall survival (OS) albeit with short-term follow-up. In order to extrapolate results to daily practice, it is critical to understand the selection of patients entered on trials since definitions of favorable and unfavorable disease vary between study groups. Currently, CMT continues to be the standard of care for the vast majority of patients with early-stage CHL and RT is an integral part of therapy in patients with bulky disease. However, for selected patients with favorable characteristics, emerging data suggest that a chemotherapy-alone approach is reasonable.

Systematic review and meta-analysis on the prognostic value of complete remission status at FDG-PET in Hodgkin lymphoma after completion of first-line therapy

This study aimed to systematically review and meta-analyze the prognostic value of complete remission status at 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in Hodgkin lymphoma after completion of first-line therapy. A systematic literature search was performed in the MEDLINE database for suitable original articles. The included studies were methodologically assessed using the Quality In Prognosis Studies tool. The proportion of patients who developed disease relapse during follow-up, among those patients who were in complete remission according to FDG-PET at the completion of first-line therapy, was calculated for each included study. Heterogeneity in disease relapse proportions across individual studies was assessed using the I2 statistic, with heterogeneity regarded present if I2<50 %. Weighted summary disease relapse proportion was calculated using either a random effects model (if I2>50) or a fixed effects model (if I2≤50). Ten studies comprising a total number of 1137 Hodgkin lymphoma patients with complete remission status according to FDG-PET after completion of first-line therapy were included. Overall methodological quality of included studies was reasonably good. The disease relapse rate during follow-up among all patients with complete remission status at end-of-treatment FDG-PET ranged from 0 to 26.7 %, with a weighted summary proportion of 7.5 % (95 % confidence interval 3.9–13.8 %) using the random effects model (I2=88.3 %). In conclusion, although the disease relapse rate in Hodgkin lymphoma patients who achieve an FDG-PET-based complete remission after first-line therapy is low from an absolute point of view, it is actually high when considering the generally favorable outcome of Hodgkin lymphoma.

The evolving role of response-adapted PET imaging in Hodgkin lymphoma

(18)F-fluorodeoxyglucose positron emission tomography with (FDG-PET) has a well-established role in the pre- and post-treatment staging of Hodgkin lymphoma (HL), however its use as a predictive therapeutic tool via responded-adapted therapy continues to evolve. There have been a multitude of retrospective and noncontrolled clinical studies showing that early (or interim) FDG-PET is highly prognostic in HL, particularly in the advanced-stage setting. Response-adapted treatment approaches in HL are attempting to diminish toxicity for low-risk patients by minimizing therapy, and conversely, intensify treatment for high-risk patients. Results from phase III noninferiority studies in early-stage HL with negative interim FDG-PET that randomized patients to chemotherapy alone versus combined modality therapy showed a continued small improvement in progression-free survival for patients who did not receive radiation. Preliminary reports of data escalating therapy for positive interim FDG-PET in early-stage HL and for de-escalation of therapy [i.e. bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine and prednisone (BEACOPP)] for negative interim FDG-PET in advanced stage HL (i.e. deletion of bleomycin) have demonstrated improved outcomes. Maturation of these studies and continued follow up of all response-adapted studies are needed. Altogether, the treatment of HL remains an individualized clinical management choice for physicians and patients. Continued refinement and optimization of FDG-PET is needed, including within the context of targeted therapeutic agents. In addition, a number of new and novel techniques of functional imaging, including metabolic tumor volume and tumor proliferation, are being explored in order to enhance staging, characterization, prognostication and ultimately patient outcome.

Post-ABVD/pre-radiotherapy (18)F-FDG-PET provides additional prognostic information for early-stage Hodgkin lymphoma: a retrospective analysis on 165 patients

OBJECTIVE

To evaluate the prognostic role of both interim fluorine-18 fludeoxyglucose positron emission tomography (i-(18)F-FDG-PET) and end-of-chemotherapy fluorine-18 fludeoxyglucose positron emission tomography (eoc-(18)F-FDG-PET) in patients with early-stage Hodgkin lymphoma (HL).

METHODS

We screened 257 patients with early-stage HL treated with combined modality therapy between March 2003 and July 2011. All were staged using fluorine-18 fludeoxyglucose positron emission tomography ((18)F-FDG-PET) before chemotherapy and after two doxorubicin, bleomycin, vinblastine and dacarbazine cycles (i-(18)F-FDG-PET); 165 patients were also evaluated by (18)F-FDG-PET at the end of chemotherapy (eoc-(18)F-FDG-PET).

RESULTS

After revision, 85% of patients were negative for i-(18)F-FDG-PET and 15% were positive. After eoc-(18)F-FDG-PET revision, 23 patients had a positive scan. The median follow-up was 56 months. The 5-year overall survival (OS) and progression-free survival (PFS) for the whole cohort were 97.5% and 95.6%, respectively. For i-(18)F-FDG-PET-negative and i-(18)F-FDG-PET-positive patients, the 5-year PFS rates were 98% and 84%, respectively; for eoc-(18)F-FDG-PET-negative and eoc-(18)F-FDG-PET-positive patients, the 5-year PFS rates were 97% and 78%, respectively. Combining the i-(18)F-FDG-PET and eoc-(18)F-FDG-PET results, the 5-year PFS were 97%, 100% and 82% in negative/negative, positive/negative and positive/positive groups, respectively. The 5-year OS rates were 98% and 83% in eoc-(18)F-FDG-PET-negative and eoc-(18)F-FDG-PET-positive patients, respectively; the 5-year OS was 98%, 100% and 83% in negative/negative, positive/negative and positive/positive groups, respectively.

CONCLUSION

This study provides additional information on the prognostic role of i-(18)F-FDG-PET and eoc-(18)F-FDG-PET in early-stage HL. As data are accumulating and the clinical scenario is rapidly evolving, we might need to rethink the use of (18)F-FDG-PET as a prognostic marker for early-stage HL in the near future.

ADVANCES IN KNOWLEDGE

This study provides additional information on the prognostic role of i-(18)F-FDG-PET and eoc-(18)F-FDG-PET in early-stage HL. On the basis of the present data, we may suggest to use eoc-(18)F-FDG-PET as a strong prognostic marker, especially for patients with i-(18)F-FDG-PET positivity.

PET/CT, MR, and PET/MR in Lymphoma and Melanoma

With the introduction of hybrid imaging technologies such as PET/CT and recently PET/MRI, staging and therapy-response monitoring have evolved. PET/CT has been shown to be of value for routine staging of FDG-avid lymphomas before as well as at the end of treatment. For interim staging, trials are ongoing to evaluate the use of PET/CT. In melanoma, PET/CT can be recommended for stages III and IV diseases for initial staging and before surgery. Studies investigating the use of PET/CT for early therapy response are promising. The role of PET/MR in lymphoma and melanoma imaging has to be defined because no larger studies exist so far. There may be an application of PET/MR in research especially for tumor characterization and therapy response. Furthermore, the potential role of non-FDG tracers is elucidated regarding the assessment of treatment response in targeted drug regimens.

Low-dose consolidation radiation therapy for early stage unfavorable Hodgkin lymphoma

PURPOSE

The German Hodgkin Study Group (GHSG) trial HD11 established 4 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and 30 Gy of radiation therapy (RT) as a standard for early stage (I, II), unfavorable Hodgkin lymphoma (HL). Additional cycles of ABVD may allow for a reduction in RT dose and improved toxicity profile.

METHODS AND MATERIALS

Patients treated with combined modality therapy at the Duke Cancer Institute for early stage, unfavorable HL by GHSG criteria from 1994 to 2012 were included. Patients who did not undergo post-chemotherapy functional imaging (positron emission tomography or gallium imaging) or who failed to achieve a complete response were excluded. Clinical outcomes were estimated using the Kaplan-Meier method. Late effects were also evaluated.

RESULTS

A total of 90 patients met inclusion criteria for analysis. Median follow-up was 5 years. Chemotherapy consisted primarily of ABVD (88%) with a median number of 6 cycles. The median dose of consolidation RT was 23.4 Gy. Four patients had relapses, 2 of which were in-field. Ten-year progression-free survival (PFS) and overall survival (OS) were 93% (95% confidence interval [CI]: 0.82-0.97) and 98% (95% CI: 0.92-0.99), respectively. For the subset of patients (n=46) who received 5 to 6 cycles of chemotherapy and ≤ 24 Gy, the 10-year PFS and OS values were 88% (95% CI: 70%-96%) and 98% (95% CI: 85% - 99%), respectively. The most common late effect was hypothyroidism (20%) with no cardiac complications. Seven secondary malignancies were diagnosed, with only 1 arising within the RT field.

CONCLUSIONS

Lower doses of RT may be sufficient when combined with more than 4 cycles of ABVD for early stage, unfavorable HL and may result in a more favorable toxicity profile than 4 cycles of ABVD and 30 Gy of RT.