PET-guided omission of radiotherapy in early-stage unfavourable Hodgkin lymphoma (GHSG HD17): a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: Combined-modality treatment consisting of chemotherapy and consolidation radiotherapy is standard of care for patients with early-stage unfavourable Hodgkin lymphoma. However, the use of radiotherapy can have long-term sequelae, which is of particular concern, as Hodgkin lymphoma is frequently diagnosed in young adults with a median age of approximately 30 years. In the German Hodgkin Study Group HD17 trial, we investigated whether radiotherapy can be omitted without loss of efficacy in patients who have a complete metabolic response after receiving two cycles of escalated doses of etoposide, cyclophosphamide, and doxorubicin, and regular doses of bleomycin, vincristine, procarbazine, and prednisone (eBEACOPP) plus two cycles of doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) chemotherapy (2 + 2). METHODS: In this multicentre, open-label, randomised, phase 3 trial, patients (aged 18-60 years) with newly diagnosed early-stage unfavourable Hodgkin lymphoma (all histologies) and an Eastern Cooperative Oncology Group performance status of 2 or less were enrolled at 224 hospitals and private practices in Germany, Switzerland, Austria, and the Netherlands. Patients were randomly assigned (1:1) to receive either standard combined-modality treatment, consisting of the 2 + 2 regimen (eBEACOPP consisted of 1250 mg/m2 intravenous cyclophosphamide on day 1, 35 mg/m2 intravenous doxorubicin on day 1, 200 mg/m2 intravenous etoposide on days 1-3, 100 mg/m2 oral procarbazine on days 1-7, 40 mg/m2 oral prednisone on days 1-14, 1·4 mg/m2 intravenous vincristine on day 8 [maximum dose of 2 mg per cycle], and 10 mg/m2 intravenous bleomycin on day 8; ABVD consisted of 25 mg/m2 intravenous doxorubicin, 10 mg/m2 intravenous bleomycin, 6 mg/m2 intravenous vinblastine, and 375 mg/m2 intravenous dacarbazine, all given on days 1 and 15) followed by 30 Gy involved-field radiotherapy (standard combined-modality treatment group) or PET4-guided treatment, consisting of the 2 + 2 regimen followed by 30 Gy of involved-node radiotherapy only in patients with positive PET at the end of four cycles of chemotherapy (PET4; PET4-guided treatment group). Randomisation was done centrally and used the minimisation method and seven stratification factors (centre, age, sex, clinical symptoms, disease localisation, albumin concentration, and bulky disease), and patients and investigators were masked to treatment allocation until central review of the PET4 examination had been completed. With the final analysis presented here, the primary objective was to show non-inferiority of the PET4-guided strategy in a per-protocol analysis of the primary endpoint of progression-free survival. We defined non-inferiority as an absolute difference of 8% in the 5-year progression-free survival estimates between the two groups. Safety analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT01356680. FINDINGS: Between Jan 13, 2012, and March 21, 2017, we enrolled and randomly assigned 1100 patients to the standard combined-modality treatment group (n=548) or to the PET4-guided treatment group (n=552); two patients in each group were found ineligible after randomisation. At a median follow-up of 46·2 months (IQR 32·7-61·2), 5-year progression-free survival was 97·3% (95% CI 94·5-98·7) in the standard combined-modality treatment group and 95·1% (92·0-97·0) in the PET4-guided treatment group (hazard ratio 0·523 [95% CI 0·226-1·211]). The between-group difference was 2·2% (95% CI -0·9 to 5·3) and excluded the non-inferiority margin of 8%. The most common grade 3 or 4 acute haematological adverse events were leucopenia (436 [83%] of 528 patients in the standard combined-modality treatment group vs 443 [84%] of 529 patients in the PET4-guided treatment group) and thrombocytopenia (139 [26%] vs 176 [33%]), and the most frequent acute non-haematological toxic effects were infection (32 [6%] vs 40 [8%]) and nausea or vomiting (38 [7%] vs 29 [6%]). The most common acute radiotherapy-associated adverse events were dysphagia (26 [6%] in the standard combined-modality treatment group vs three [2%] in the PET4-guided treatment group) and mucositis (nine [2%] vs none). 229 serious adverse events were reported by 161 (29%) of 546 patients in the combined-modality treatment group, and 235 serious adverse events were reported by 164 (30%) of 550 patients in the PET4-guided treatment group. One suspected unexpected serious adverse reaction (infection) leading to death was reported in the PET4-guided treatment group. INTERPRETATION: PET4-negativity after treatment with 2 + 2 chemotherapy in patients with newly diagnosed early-stage unfavourable Hodgkin lymphoma allows omission of consolidation radiotherapy without a clinically relevant loss of efficacy. PET4-guided therapy could thereby reduce the proportion of patients at risk of the late effects of radiotherapy. FUNDING: Deutsche Krebshilfe.

Outcome-based interpretation of early interim PET in advanced-stage Hodgkin lymphoma.

The HD18 study for patients with newly diagnosed advanced-stage Hodgkin lymphoma (HL) used positron emission tomography (PET) after 2 cycles (PET-2) of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone in escalated doses (eBEACOPP) to guide further treatment. Here, we analyzed the impact of PET-2 results in the context of eBEACOPP according to the Deauville score (DS) in patients treated within the HD18 trial. Residual tissue was visually compared with reference regions according to DS. We analyzed the association between PET-2 uptake and baseline characteristics, progression-free survival (PFS), and overall survival (OS). One thousand five patients (52%) had DS1 or DS2, 471 (24%) had DS3, and 469 (24%) DS4. PET-2 uptake was associated with baseline risk factors large mediastinal mass, extranodal disease, and high International Prognostic Score (P < .0001 each). Among 722 patients receiving standard therapy with 6 cycles of eBEACOPP, 3-year PFS rates were 92.2%, 95.9%, and 87.6% with DS1-2, DS3, and DS4, respectively. Univariate hazard ratio (HR) for PFS in patients with DS4 vs DS1-3 was 2.3 (1.3-3.8; P = .002). DS4 was the only factor remaining significant for PFS in a multivariate analysis including the associated baseline risk factors. Three-year OS rates were 97.6% for DS1-2, 99.0% for DS3, and 96.8% for DS4, with a univariate HR for DS4 vs DS1-3 of 2.6 (1.0-6.6; P = .04). Residual uptake above that in the liver at PET-2 (ie, DS4) is an important risk factor regarding survival outcomes for patients treated with eBEACOPP upfront. We thus recommend DS4 as the cutoff value for PET-2 positivity. This trial was registered at www.clinicaltrials.gov as #NCT00515554.

PET-guided treatment in patients with advanced-stage Hodgkin's lymphoma (HD18): final results of an open-label, international, randomised phase 3 trial by the German Hodgkin Study Group.

BACKGROUND: The intensive polychemotherapy regimen eBEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone in escalated doses) is very active in patients with advanced-stage Hodgkin's lymphoma, albeit at the expense of severe toxicities. Individual patients might be cured with less burdensome therapy. We investigated whether metabolic response determined by PET after two cycles of standard regimen eBEACOPP (PET-2) would allow adaption of treatment intensity, increasing it for PET-2-positive patients and reducing it for PET-2-negative patients. METHODS: In this open-label, randomised, parallel-group phase 3 trial, we recruited patients aged 18-60 years with newly diagnosed, advanced-stage Hodgkin's lymphoma in 301 hospitals and private practices in Germany, Switzerland, Austria, the Netherlands, and the Czech Republic. After central review of PET-2, patients were assigned (1:1) to one of two parallel treatment groups on the basis of their PET-2 result. Patients with positive PET-2 were randomised to receive six additional cycles of either standard eBEACOPP (8 × eBEACOPP in total) or eBEACOPP with rituximab (8 × R-eBEACOPP). Those with negative PET-2 were randomised between standard treatment with six additional cycles of eBEACOPP (8 × eBEACOPP) or experimental treatment with two additional cycles (4 × eBEACOPP). A protocol amendment in June, 2011, introduced a reduction of standard therapy to 6 × eBEACOPP; after this point, patients with positive PET-2 were no longer randomised and were all assigned to receive 6 × eBEACOPP and patients with negative PET-2 were randomly assigned to 6 × eBEACOPP (standard) or 4 × eBEACOPP (experimental). Randomisation was done centrally using the minimisation method including a random component, stratified according to centre, age (<45 vs ≥45 years), stage (IIB, IIIA vs IIIB, IV), international prognostic score (0-2 vs 3-7), and sex. eBEACOPP was given as previously described; rituximab was given intravenously at a dose of 375 mg/m2 (maximum total dose 700 mg). The primary objectives were to show superiority of the experimental treatment in the PET-2-positive cohort, and to show non-inferiority of the experimental treatment in the PET-2-negative cohort in terms of the primary endpoint, progression-free survival. We defined non-inferiority as an absolute difference of 6% in the 5-year progression-free survival estimates. Primary analyses in the PET-2-negative cohort were per protocol; all other analyses were by intention to treat. This trial was registered with ClinicalTrials.gov, number NCT00515554. FINDINGS: Between May 14, 2008, and July 18, 2014, we recruited 2101 patients, of whom 137 were found ineligible before randomisation and a further 19 were found ineligible after randomisation. Among 434 randomised patients (217 per arm) with positive PET-2, 5-year progression-free survival was 89·7% (95% CI 85·4-94·0) with eBEACOPP and 88·1% (83·5-92·7) with R-eBEACOPP (log-rank p=0·46). Patients with negative PET-2 randomly assigned to either 8 × eBEACOPP or 6 × eBEACOPP (n=504) or 4 × eBEACOPP (n=501) had 5-year progression-free survival of 90·8% (95% CI 87·9-93·7) and 92·2% (89·4-95·0), respectively (difference 1·4%, 95% CI -2·7 to 5·4). 4 × eBEACOPP was associated with fewer severe infections (40 [8%] of 498 vs 75 [15%] of 502) and organ toxicities (38 [8%] of 498 vs 91 [18%] of 502) than were 8 × eBEACOPP or 6 × eBEACOPP in PET-2-negative patients. Ten treatment-related deaths occurred: four in the PET-2-positive cohort (one [<1%] in the 8 × eBEACOPP group, three [1%] in the 8 × R-eBEACOPP group) and six in the PET-2-negative group (six [1%] in the 8 × eBEACOPP or 6 × eBEACOPP group). INTERPRETATION: The favourable outcome of patients treated with eBEACOPP could not be improved by adding rituximab after positive PET-2. PET-2 negativity allows reduction to only four cycles of eBEACOPP without loss of tumour control. PET-2-guided eBEACOPP provides outstanding efficacy for all patients and increases overall survival by reducing treatment-related risks for patients with negative PET-2. We recommend this PET-2-guided treatment strategy for patients with advanced-stage Hodgkin's lymphoma. FUNDING: Deutsche Krebshilfe, Swiss State Secretariat for Education and Research, and Roche Pharma AG.

Progression-free survival of early interim PET-positive patients with advanced stage Hodgkin's lymphoma treated with BEACOPPescalated alone or in combination with rituximab (HD18): an open-label, international, randomised phase 3 study by the German Hodgkin Study Group.

BACKGROUND: Advanced stage Hodgkin's lymphoma represents a heterogeneous group of patients with different risk profiles. Data suggests that interim PET assessment during chemotherapy is superior to baseline international prognostic scoring in terms of predicting long-term treatment outcome in patients with Hodgkin's lymphoma. We therefore hypothesised that early interim PET-imaging after two courses of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP) might be suitable for guiding treatment in patients with advanced stage Hodgkin's lymphoma. We aimed to assess whether intensifying standard chemotherapy (BEACOPPescalated) by adding rituximab would improve progression-free survival in patients with positive PET after two courses of chemotherapy. METHODS: In this open-label, international, randomised, phase 3 study, we recruited patients aged 18-60 years with newly diagnosed, advanced stage Hodgkin's lymphoma from 160 hospitals and 77 private practices in Germany, Switzerland, Austria, the Netherlands, and the Czech Republic. Interim PET-imaging was done after two cycles of BEACOPPescalated and centrally assessed by an expert panel. Patients with a positive PET after 2 cycles of BEACOPPescalated chemotherapy (PET-2) were randomly assigned (1:1) to receive six additional courses of either BEACOPPescalated (BEACOPPescalated group) or BEACOPPescalated plus rituximab (R-BEACOPPescalated group). PET-2 was assessed using a 5-point scale with 18FDG uptake higher than the mediastinal blood pool (corresponding to Deauville scale 3) defined as positive. BEACOPPescalated was given as previously described; rituximab was given intravenously at a dose of 375 mg/m2 (maximum total dose 700 mg), the first administration starting 24 h before starting the fourth cycle of BEACOPPescalated (day 0 and day 3 in cycle 4, day 1 in cycles 5-8). Randomisation was done centrally and used the minimisation method including a random component, stratified according to centre, age, stage, international prognostic score, and sex. The primary efficacy endpoint was 5 year progression-free survival, analysed in the intention-to-treat population. We are reporting this second planned interim analysis as the final report of the trial. The trial is registered with ClinicalTrials.gov, number NCT00515554. FINDINGS: Between May 14, 2008, and May 31, 2011, we enrolled 1100 patients. 440 patients had a positive PET-2 and were randomly assigned to either the BEACOPPescalated group (n=220) or the R-BEACOPPescalated group (n=220). With a median follow-up of 33 months (IQR 25-42) for progression-free survival, estimated 3 year progression-free survival was 91·4% (95% CI 87·0-95·7) for patients in the BEACOPPescalated group and 93·0% (89·4-96·6) for those in the R-BEACOPPescalated group (difference 1·6%, 95% CI -4·0 to 7·3; log rank p=0·99). Common grade 3-4 adverse events were leucopenia (207 [95%] of 218 patients in the BEACOPPescalated group vs 211 [96%] of 220 patients in the R-BEACOPPescalated group), and severe infections (51 [23%] vs 43 [20%] patients). Based on a futility analysis, the independent data monitoring committee recommended publication of this second planned interim analysis as the final result. Six (3%) of 219 patients in the BEACOPPescalated group and ten (5%) of 220 in the R-BEACOPPescalated group died; fatal treatment-related toxic effects occurred in one (<1%) patient in the BEACOPPescalated group and three (1%) in the R-BEACOPPescalated group, all of them due to infection. INTERPRETATION: The addition of rituximab to BEACOPPescalated did not improve the progression-free survival of PET-2 positive patients with advanced stage Hodgkin's lymphoma. However, progression-free survival for PET-2 positive patients was much better than expected, exceeding even the outcome of PET-2-unselected patients in the previous HD15 trial. Thus, PET-2 cannot identify patients at high-risk for treatment failure in the context of the very effective German Hodgkin Study Group standard treatment for advanced stage Hodgkin's lymphoma. FUNDING: Deutsche Krebshilfe; Swiss State Secretariat for Education, Research and Innovation (SERI); and Roche Pharma.

Incorporation of brentuximab vedotin into first-line treatment of advanced classical Hodgkin's lymphoma: final analysis of a phase 2 randomised trial by the German Hodgkin Study Group.

BACKGROUND: A high proportion of patients with relapsed classical Hodgkin's lymphoma achieve a response with the antibody-drug conjugate brentuximab vedotin, and the drug is well tolerated. We modified the escalated BEACOPP regimen (eBEACOPP; bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) and implemented brentuximab vedotin with the aim to reduce toxic effects while maintaining the protocol's efficacy. METHODS: We did an open-label, multicentre, randomised phase 2 study at 20 study sites in Germany. Adult patients (aged 18-60 years) with newly diagnosed, advanced, classical Hodgkin's lymphoma were randomly assigned (1:1) to treatment with six cycles of either BrECAPP (brentuximab vedotin 1·8 mg/kg on day 1, etoposide 200 mg/m2 on days 2-4, doxorubicin 35 mg/m2 on day 2, cyclophosphamide 1250 mg/m2 on day 2, procarbazine 100 mg/m2 on days 2-8, and prednisone 40 mg/m2 on days 2-15) or BrECADD (brentuximab vedotin 1·8 mg/kg on day 1, etoposide 150 mg/m2 on days 2-4, doxorubicin 40 mg/m2 on day 2, cyclophosphamide 1250 mg/m2 on day 2, dacarbazine 250 mg/m2 on days 3-4, and dexamethasone 40 mg on days 2-5). Randomisation was done centrally by stratified minimisation, with study site and sex as stratification factors. The co-primary endpoints were complete response to chemotherapy and complete remission at the end of treatment, which were assessed by intention to treat. Patients who were found not to meet inclusion criteria after randomisation or without restaging data after two cycles of study treatment were excluded from the primary endpoint analysis. All patients who started study treatment were assessable for safety. This report presents the final analysis at a median follow-up of 17 months (IQR 13·2-21·5). The preplanned 2-year follow-up analysis is yet to be reported. This trial is registered with ClinicalTrials.gov, number NCT01569204. FINDINGS: Between Oct 26, 2012, and May 15, 2014, 104 patients were enrolled to the study (52 were assigned to each study arm). Two patients dropped out before the start of study treatment because of acute infection (n=1) and withdrawal of consent (n=1) and one patient was excluded because of intermediate-stage disease (all were assigned BrECAPP). 42 (86%, 95% CI 73-94) of 49 patients assigned BrECAPP achieved a complete response after chemotherapy and 46 (94%, 95% CI 83-99) had complete remission as their final treatment outcome. In the BrECADD group, 46 (88%, 95% CI 77-96) of 52 patients achieved both a complete response after chemotherapy and complete remission as their final treatment outcome. 58 serious adverse events were reported, 32 events in 21 of 50 patients who received BrECAPP and 26 events in 18 of 52 patients who received BrECADD. The most common grade 3-4 toxic effects were haematological adverse events (91 [89%] of 102 patients). Grade 3-4 organ toxic effects were reported in seven (17%) of 42 patients assigned BrECAPP and two (4%) of 46 allocated BrECADD. 16 (32%) of 50 patients assigned BrECAPP and 18 (35%) of 52 allocated BrECADD had grade 1-2 peripheral neuropathy, and one (2%) patient assigned BrECAPP developed grade 3 peripheral neuropathy; all but one case (allocated BrECAPP) resolved. No deaths were reported during the follow-up period. INTERPRETATION: Both eBEACOPP variants met the co-primary efficacy endpoints. Particularly, the BrECADD regimen was associated with a more favourable toxicity profile and was, therefore, selected to challenge standard eBEACOPP for the treatment of advanced classical Hodgkin's lymphoma in the phase 3 HD21 study by the German Hodgkin Study Group (NCT02661503), which aims to further reduce treatment-related morbidity. FUNDING: Takeda Pharmaceuticals.

A phase 1 study of the bispecific anti-CD30/CD16A antibody construct AFM13 in patients with relapsed or refractory Hodgkin lymphoma.

AFM13 is a bispecific, tetravalent chimeric antibody construct (TandAb) designed for the treatment of CD30-expressing malignancies. AFM13 recruits natural killer (NK) cells via binding to CD16A as immune effector cells. In this phase 1 dose-escalation study, 28 patients with heavily pretreated relapsed or refractory Hodgkin lymphoma received AFM13 at doses of 0.01 to 7 mg/kg body weight. Primary objectives were safety and tolerability. Secondary objectives included pharmacokinetics, antitumor activity, and pharmacodynamics. Adverse events were generally mild to moderate. The maximum tolerated dose was not reached. Pharmacokinetics assessment revealed a half-life of up to 19 hours. Three of 26 evaluable patients achieved partial remission (11.5%) and 13 patients achieved stable disease (50%), with an overall disease control rate of 61.5%. AFM13 was also active in brentuximab vedotin-refractory patients. In 13 patients who received doses of ≥1.5 mg/kg AFM13, the overall response rate was 23% and the disease control rate was 77%. AFM13 treatment resulted in a significant NK-cell activation and a decrease of soluble CD30 in peripheral blood. In conclusion, AFM13 represents a well-tolerated, safe, and active targeted immunotherapy of Hodgkin lymphoma. A phase 2 study is currently planned to optimize the dosing schedule in order to further improve the therapeutic efficacy. This phase 1 study was registered at www.clinicaltrials.gov as #NCT01221571.

Impact of PET/CT image reconstruction methods and liver uptake normalization strategies on quantitative image analysis.

BACKGROUND: In oncological imaging using PET/CT, the standardized uptake value has become the most common parameter used to measure tracer accumulation. The aim of this analysis was to evaluate ultra high definition (UHD) and ordered subset expectation maximization (OSEM) PET/CT reconstructions for their potential impact on quantification. PATIENTS AND METHODS: We analyzed 40 PET/CT scans of lung cancer patients who had undergone PET/CT. Standardized uptake values corrected for body weight (SUV) and lean body mass (SUL) were determined in the single hottest lesion in the lung and normalized to the liver for UHD and OSEM reconstruction. Quantitative uptake values and their normalized ratios for the two reconstruction settings were compared using the Wilcoxon test. The distribution of quantitative uptake values and their ratios in relation to the reconstruction method used were demonstrated in the form of frequency distribution curves, box-plots and scatter plots. The agreement between OSEM and UHD reconstructions was assessed through Bland-Altman analysis. RESULTS: A significant difference was observed after OSEM and UHD reconstruction for SUV and SUL data tested (p < 0.0005 in all cases). The mean values of the ratios after OSEM and UHD reconstruction showed equally significant differences (p < 0.0005 in all cases). Bland-Altman analysis showed that the SUV and SUL and their normalized values were, on average, up to 60 % higher after UHD reconstruction as compared to OSEM reconstruction. CONCLUSION: OSEM and HD reconstruction brought a significant difference for SUV and SUL, which remained constantly high after normalization to the liver, indicating that standardization of reconstruction and the use of comparable SUV measurements are crucial when using PET/CT.

Follow-up of the GHSG HD16 trial of PET-guided treatment in early-stage favorable Hodgkin lymphoma.

The primary analysis of the GHSG HD16 trial indicated a significant loss of tumor control with PET-guided omission of radiotherapy (RT) in patients with early-stage favorable Hodgkin lymphoma (HL). This analysis reports long-term outcomes. Overall, 1150 patients aged 18-75 years with newly diagnosed early-stage favorable HL were randomized between standard combined-modality treatment (CMT) (2x ABVD followed by PET/CT [PET-2] and 20 Gy involved-field RT) and PET-2-guided treatment omitting RT in case of PET-2 negativity (Deauville score [DS] < 3). The study aimed at excluding inferiority of PET-2-guided treatment and assessing the prognostic impact of PET-2 in patients receiving CMT. At a median follow-up of 64 months, PET-2-negative patients had a 5-year progression-free survival (PFS) of 94.2% after CMT (n = 328) and 86.7% after ABVD alone (n = 300; HR = 2.05 [1.20-3.51]; p = 0.0072). 5-year OS was 98.3% and 98.8%, respectively (p = 0.14); 4/12 documented deaths were caused by second primary malignancies and only one by HL. Among patients assigned to CMT, 5-year PFS was better in PET-2-negative (n = 353; 94.0%) than in PET-2-positive patients (n = 340; 90.3%; p = 0.012). The difference was more pronounced when using DS4 as cut-off (DS 1-3: n = 571; 94.0% vs. DS ≥ 4: n = 122; 83.6%; p < 0.0001). Taken together, CMT should be considered standard treatment for early-stage favorable HL irrespective of the PET-2-result.

Quantitative assessment of 18F-FDG PET in patients with Hodgkin lymphoma: is it significantly affected by contrast-enhanced computed tomography attenuation correction?

OBJECTIVE: The reliability of visual and quantitative response assessment may be impaired owing to inconsistent scanning protocols and image reconstruction methods of 2-deoxy-2-[F]fluoro-D-glucose (F-FDG) PET. Hence, this study investigates the effect of contrast-enhanced computed tomography (CT) attenuation correction in patients with Hodgkin lymphoma. PATIENTS AND METHODS: In 10 consecutive patients undergoing either staging or response assessment, F-FDG PET images were attenuation-corrected once on the basis of unenhanced CT and additionally using contrast-enhanced CT. Reconstruction was performed in both cases with ordered subset expectation maximization (OSEM) and ultra-high definition (UHD) algorithm. While maximum and peak standardized uptake value (SUV) were obtained from tumour tissue (lesionSUVmax and lesionSUVpeak), maximum and mean SUVs were determined within the background regions liver (liverSUVmax and liverSUVmean) and mediastinal blood pool (mbpSUVmax and mbpSUVmean). RESULTS: After switching to contrast-enhanced CT attenuation correction, lesionSUVmax and lesionSUVpeak increased on average by 2.55±3.24 (P=0.018) and 3.64±3.22% (P=0.008), respectively, with OSEM and by 4.59±5.49 (P=0.005) and 3.84±5.65% (P=0.005), respectively, with UHD reconstruction. LiverSUVmax and liverSUVmean showed a mean rise of 7.15±4.27 (P=0.005) and 6.97±2.18% (P=0.005), respectively, in the OSEM data sets and of 7.24±6.59 (P=0.017) and 6.29±2.83% (P=0.005), respectively, in the UHD images. The average increases of mbpSUVmax and mbpSUVmean were 10.82±4.89 (P=0.005) and 12.40±3.73% (P=0.005), respectively, after OSEM, compared with 13.11±14.93 (P=0.005) and 11.50±12.19% (P=0.005), respectively, after UHD reconstruction. CONCLUSION: As the use of CT contrast fluids results in a stronger SUV increase within the liver and mediastinal blood pool than within lymphoma tissue, this may have clinical consequences regarding visual and quantitative response assessment. Ideally, CT scans for PET attenuation correction should therefore be performed in the absence of a contrast agent.

Positron Emission Tomography-Guided Treatment in Early-Stage Favorable Hodgkin Lymphoma: Final Results of the International, Randomized Phase III HD16 Trial by the German Hodgkin Study Group.

PURPOSE: Combined-modality treatment (CMT) with 2× ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) and small-field radiotherapy is standard of care for patients with early-stage favorable Hodgkin lymphoma (HL). However, the role of radiotherapy has been challenged. Positron emission tomography (PET) after 2× ABVD (PET-2) might help to predict individual outcomes and guide treatment. METHODS: Between November 2009 and December 2015, we recruited patients age 18 to 75 years with newly diagnosed, early-stage favorable HL for this international randomized phase III trial. Patients were assigned to standard CMT of 2× ABVD and 20-Gy involved-field radiotherapy or PET-guided treatment, omitting involved-field radiotherapy after negative PET-2 (Deauville score < 3). Primary objectives were to exclude inferiority of 10% or more in 5-year progression-free survival (PFS) of ABVD alone compared with CMT in a per-protocol analysis among PET-2-negative patients (noninferiority margin for hazard ratio, 3.01) and to confirm PET-2 positivity (Deauville score ≥ 3) as a risk factor for PFS among CMT-treated patients. RESULTS: We enrolled 1,150 patients. Median follow-up was 45 months. Among 628 PET-2-negative, per-protocol-treated patients, 5-year PFS was 93.4% (95% CI, 90.4% to 96.5%) with CMT and 86.1% (95% CI, 81.4% to 90.9%) with ABVD (difference 7.3% [95% CI, 1.6% to 13.0%]; hazard ratio, 1.78 [95% CI, 1.02 to 3.12]). Five-year overall survival was 98.1% (95% CI, 96.5% to 99.8%) with CMT and 98.4% (95% CI, 96.5% to 100.0%) with ABVD. Among 693 patients who were assigned to CMT, 5-year PFS was 93.2% (95% CI, 90.2% to 96.2%) among PET-2-negative patients and 88.4% (95% CI, 84.2% to 92.6%) in PET-2-positive patients (P = .047). When using the more common liver cutoff (Deauville score, 4) for PET-2 positivity, the difference was more pronounced (5-year PFS, 93.1% [95% CI, 90.7% to 95.5%] v 80.9% [95% CI, 72.2% to 89.7%]; P = .0011). CONCLUSION: In early-stage favorable HL, a positive PET after two cycles ABVD indicates a high risk for treatment failure, particularly when a Deauville score of 4 is used as a cutoff for positivity. In PET-2-negative patients, radiotherapy cannot be omitted from CMT without clinically relevant loss of tumor control.

Metabolic Tumour Volume for Response Prediction in Advanced-Stage Hodgkin Lymphoma.

Rationale: (18F)fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) for staging Hodgkin lymphoma may allow for accurate and reliable assessment of the metabolic tumour volume (MTV) as baseline risk factor. Our aim was to analyse the prognostic impact of MTV measurements, obtained by different means in advanced-stage Hodgkin lymphoma patients treated within the German Hodgkin Study Group HD18 trial. Methods: Within the German Hodgkin Study Group trial HD18, 310 patients underwent 18F-FDG PET/CT scanning for staging which was available to the central review panel for quantitative analysis. We calculated the MTV by four different thresholding methods and performed receiver operating characteristic (ROC) analysis to evaluate the potential for prediction of early response determined by PET after two cycles (PET-2) dose-escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (eBEACOPP). Logistic regression was used to evaluate its prognostic value concerning progression-free survival (PFS) and overall survival (OS). Results: All different MTV calculations used predicted PET-2 response to a moderate and comparable degree (area under the curve = 0.62-0.63, P = 0.01-0.06). With none of the measuring methods did the ROC curves point to any unique cut-off values, but indicated a wide range of possible cut-offs. However, none of the MTV measurements was prognostic for PFS (Hazard ratio 1.2-1.5, P = 0.15-0.52) or OS (Hazard ratio 1.0-1.5, P = 0.95 - 0.27). Conclusion: Baseline MTV as determined by different means, is a predictive factor for early response to eBEACOPP after two cycles. However, value as a prognostic factor after highly effective PET-2 adapted treatment strategy could not be observed.

In vivo Patterns of Tau Pathology, Amyloid-ß Burden, and Neuronal Dysfunction in Clinical Variants of Alzheimer's Disease.

The clinical heterogeneity of Alzheimer's disease is not reflected in the rather diffuse cortical deposition of amyloid-ß. We assessed the relationship between clinical symptoms, in vivo tau pathology, amyloid distribution, and hypometabolism in variants of Alzheimer's disease using novel multimodal PET imaging techniques. Tau pathology was primarily observed in brain regions related to clinical symptoms and overlapped with areas of hypometabolism. In contrast, amyloid-ß deposition was diffusely distributed over the entire cortex. Tau PET imaging may thus serve as a valuable biomarker for the localization of neuronal injury in vivo and may help to validate atypical subtypes of Alzheimer's disease.

Comparison of [(18)F]DCFPyL and [ (68)Ga]Ga-PSMA-HBED-CC for PSMA-PET Imaging in Patients with Relapsed Prostate Cancer.

PURPOSE: Gallium-68 (Ga-68)-labeled tracers for imaging expression of the prostate-specific membrane antigen (PSMA) such as the [(68)Ga]Ga-PSMA-HBED-CC have already demonstrated high potential for the detection of recurrent prostate cancer. However, compared to Ga-68, a labeling with fluorine-18 (F-18) would offer advantages with respect to availability, production amount, and image resolution. [(18)F]DCFPyL is a promising F-18-labeled candidate for PSMA-positron emission tomography (PET) imaging that has been recently introduced. In the current study, we aimed to compare [(68)Ga]Ga-PSMA-HBED-CC and [(18)F]DCFPyL for clinical use in biochemically relapsed prostate cancer. PROCEDURES: In 14 selected patients with PSA relapse of prostate cancer, [(18)F]DCFPyL PET/X-ray computed tomography (CT) was performed in addition to [(68)Ga]Ga-PSMA-HBED-CC PET/CT. A systematic comparison was carried out between results obtained with both tracers with regard to the number of detected PSMA-positive lesions, the standardized uptake value (SUV)max and the lesion to background ratios. RESULTS: All suspicious lesions identified by [(68)Ga]Ga-PSMA-HBED-CC were also detected with [(18)F]DCFPyL. In three patients, additional lesions were observed using [(18)F]DCFPyL PET/CT. The mean SUVmax in the concordant [(18)F]DCFPyL PSMA-positive lesions was significantly higher as compared to [(68)Ga]Ga-PSMA-HBED-CC (14.5 vs. 12.2, p = 0.028, n = 15). The mean tumor to background ratios (n = 15) were significantly higher for [(18)F]DCFPyL compared to [(68)Ga]Ga-PSMA-HBED-CC using kidney, spleen, or parotid as reference organs (p = 0.006, p = 0.002, p = 0.008), but no significant differences were found using the liver (p = 0.167) or the mediastinum (p = 0.363) as reference organs. CONCLUSION: [(18)F]DCFPyL PET/CT provided a high image quality and visualized small prostate lesions with excellent sensitivity. [(18)F]DCFPyL represents a highly promising alternative to [(68)Ga]Ga-PSMA-HBED-CC for PSMA-PET/CT imaging in relapsed prostate cancer.

Relapse analysis of irradiated patients within the HD15 trial of the German Hodgkin Study Group.

PURPOSE: To determine, in the setting of advanced-stage of Hodgkin lymphoma (HL), whether relapses occur in the irradiated planning target volume and whether the definition of local radiation therapy (RT) used by the German Hodgkin Study Group (GHSG) is adequate, because there is no harmonization of field and volume definitions among the large cooperative groups in the treatment of advanced-stage HL. METHODS AND MATERIALS: All patients with residual disease of ≥ 2.5 cm after multiagent chemotherapy (CTX) were evaluated using additional positron emission tomography (PET), and those with a PET-positive result were irradiated with 30 Gy to the site of residual disease. We re-evaluated all sites of disease before and after CTX, as well as the PET-positive residual tumor that was treated in all relapsed patients. Documentation of radiation therapy (RT), treatment planning procedures, and portal images were carefully analyzed and compared with the centrally recommended RT prescription. The irradiated sites were compared with sites of relapse using follow-up computed tomography scans. RESULTS: A total of 2126 patients were enrolled, and 225 patients (11%) received RT. Radiation therapy documents of 152 irradiated patients (68%) were analyzed, with 28 irradiated patients (11%) relapsing subsequently. Eleven patients (39%) had an in-field relapse, 7 patients (25%) relapsed outside the irradiated volume, and an additional 10 patients (36%) showed mixed in- and out-field relapses. Of 123 patients, 20 (16%) with adequately performed RT relapsed, compared with 7 of 29 patients (24%) with inadequate RT. CONCLUSIONS: The frequency and pattern of relapses suggest that local RT to PET-positive residual disease is sufficient for patients in advanced-stage HL. Insufficient safety margins of local RT may contribute to in-field relapses.

18-Fluorodeoxyglucose positron emission tomography/computed tomography for assessment of response to brentuximab vedotin treatment in relapsed and refractory Hodgkin lymphoma.

Brentuximab vedotin has emerged as a possible treatment option in patients suffering from relapsed and refractory Hodgkin lymphoma (HL). We investigated the role of 18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for monitoring treatment response to brentuximab vedotin in patients with relapsed and refractory HL. Twelve consecutive, heavily pretreated patients with relapsed and refractory HL treated with brentuximab vedotin were available for analysis. FDG-PET/CT studies were performed early during treatment after a median of 3 cycles (range, 2-5 cycles), and were analyzed visually using a 5-point scale (5PS) and quantitatively using the maximum standardized uptake value (SUV(max)) and the three-dimensional (3D) isocontour at 50% of the maximum pixel value (SUV(50)) in the hottest single lesion. The median follow-up in our study cohort was 16 months (range, 5-30 months). The median progression-free survival (PFS) was 12.5 months and PFS at 12 months was 58%. Patients treated with brentuximab vedotin and negative interim FDG-PET/CT assessed by visual or quantitative analysis demonstrated a significantly prolonged PFS compared to patients with positive interim FDG-PET/CT. The 1-year PFS was 100% in patients with negative interim FDG-PET/CT assessed by visual analysis, whereas patients with positive interim FDG-PET/CT had a worse outcome with a 1-year PFS of 38% (p = 0.033). The 1-year PFS was 75% in patients with negative interim FDG-PET/CT assessed by quantitative analysis using the SUV(50), whereas patients with positive interim FDG-PET/CT had a worse outcome with a 1-year PFS of 25% (p = 0.017) Interim FDG-PET/CT might be a suitable diagnostic approach to predict response to brentuximab vedotin in relapsed and refractory HL.

Assessment of tumor size reduction improves outcome prediction of positron emission tomography/computed tomography after chemotherapy in advanced-stage Hodgkin lymphoma.

PURPOSE: Positron emission tomography (PET) after chemotherapy can guide consolidating radiotherapy in advanced-stage Hodgkin lymphoma (HL). This analysis aims to improve outcome prediction by integrating additional criteria derived by computed tomography (CT). PATIENTS AND METHODS: The analysis set consisted of 739 patients with residues≥2.5 cm after chemotherapy from a total of 2,126 patients treated in the HD15 trial (HD15 for advanced stage Hodgkin's disease: Quality assurance protocol for reduction of toxicity and the prognostic relevance of fluorodeoxyglucose-positron-emission tomography [FDG-PET] in the first-line treatment of advanced-stage Hodgkin's disease) performed by the German Hodgkin Study Group. A central panel performed image analysis and interpretation of CT scans before and after chemotherapy as well as PET scans after chemotherapy. Prognosis was evaluated by using progression-free survival (PFS); groups were compared with the log-rank test. Potential prognostic factors were investigated by using receiver operating characteristic analysis and logistic regression. RESULTS: In all, 548 (74%) of 739 patients had PET-negative residues after chemotherapy; these patients did not receive additional radiotherapy and showed a 4-year PFS of 91.5%. The 191 PET-positive patients (26%) receiving additional radiotherapy had a 4-year PFS of 86.1% (P=.022). CT alone did not allow further separation of patients in partial remission by risk of recurrence (P=.9). In the subgroup of the 54 PET-positive patients with a relative reduction of less than 40%, the risk of progression or relapse within the first year was 23.1% compared with 5.3% for patients with a larger reduction (difference, 17.9%; 95% CI, 5.8% to 30%). CONCLUSION: Patients with HL who have PET-positive residual disease after chemotherapy and poor tumor shrinkage are at high risk of progression or relapse.

Brentuximab vedotin (SGN-35) in patients with transplant-naive relapsed/refractory Hodgkin lymphoma.

Only limited data are available on the role of brentuximab vedotin (SGN-35) in transplant-naive relapsed or refractory patients with Hodgkin lymphoma (HL). We thus retrospectively analyzed 14 patients with primary refractory or relapsed HL who were treated with brentuximab vedotin as single agent in a named patient program, who had not received prior high-dose chemotherapy (HDCT) and autologous stem cell transplant (ASCT) due to refractory disease (n = 9), comorbidity (n = 4) and unknown reasons (n = 1). Brentuximab vedotin resulted in an overall response rate of 71% (10/14) with five complete responses (CRs). Five of those patients with refractory disease and four patients with relevant comorbidity responded. Consolidating ASCT (n = 4) or allogeneic SCT (n = 1) was performed in five patients. Median progression-free survival (PFS) was 9 months and the median overall survival (OS) was not reached. These data indicate the therapeutic efficacy of brentuximab vedotin in chemotherapy-refractory transplant-naive patients with HL.