Prognostic value of baseline metabolic tumor volume in children and adolescents with intermediate-risk Hodgkin lymphoma treated with chemo-radiation therapy: FDG-PET parameter analysis in a subgroup from COG AHOD0031

Role of 18F-Fluorodeoxyglucose Positron Emission Tomography in Children With Germ Cell Tumor After Chemotherapy

BACKGROUND/AIM

18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is a diagnostic tool widely used in adult oncology and some pediatric oncological settings. There are no established recommendations for the use of this imaging modality in pediatric malignant germ cell tumors (mGCT), however. Our aim is to evaluate the role of 18F-FDG PET/CT in the restaging of mGCT after chemotherapy in children and adolescents.

METHODS

We retrospectively reviewed patients with mGCT treated in Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) centers who underwent 18F-FDG PET/CT between 2011 and 2021.

RESULTS

Seventeen patients (median age 13 y) were included in the study. In 14 patients, 18F-FDG PET/CT was performed at diagnosis; 12 showed pathologic uptake. The 2 18F-FDG PET/CT negative cases were histologically defined as yolk sac tumor (YST) and mixed (chorioncarcinoma, YST). Nine of the 12 patients who had pathologic 18F-FDG PET/CT at diagnosis repeated the examination after neoadjuvant chemotherapy, before, second look surgery. In 5 cases, no pathologic uptake was evident. Histology showed necrosis alone in 4 cases and necrosis and mature teratoma in 1. In 3 of the 6 cases with pathologic uptake (2 of 6 patients did not perform the examination at diagnosis), histology showed persistence of malignant component, whereas in the remaining 3 cases, necrosis and mature teratoma were present.

CONCLUSION

In our review of a series of children with mGCT, 18F-FDG PET/CT after neoadjuvant chemotherapy showed 1 of 5 false negatives and was unable to discriminate between residual malignant component and mature teratoma.

Prognostic value of baseline and interim [18F]FDG PET metabolic parameters in pediatric Hodgkin's lymphoma

BACKGROUND

Hodgkin lymphoma (HL) in pediatric populations has a high survival rate but poses risks for long-term morbidities. Although [18F]fluoro‑2‑deoxy‑2‑d‑glucose positron emission tomography ([18F]FDG PET) scans offer potential for improved risk stratification, the definitive prognostic value of quantitative [18F]FDG PET parameters remains unclear for pediatric HL.

METHODS

A single-center, retrospective study included pediatric patients diagnosed with HL between 2016 and 2023 treated according to EuroNet-PHL-C1 and DAL/GPOH-HD protocols. Patients underwent baseline and interim PET/CT scans after two chemotherapy cycles. Event-free survival (EFS) was the primary endpoint, Deauville score was the secondary endpoint. Quantitative [18F]FDG PET parameters included SUVmax, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) that were evaluated using two segmentation methods (SUV 2.5, 41% SUVmax). Survival outcomes were assessed using Cox regression analysis.

RESULTS

A total of 115 patients (50 males, median age 14.2 years) were studied, with a median follow-up period of 35 months. During this period, 16 cases (13.9%) of relapse or progression were noted. Baseline and interim MTV 2.5, MTV 41%, TLG 2.5, and TLG 41%, along with interim SUVmax, were significantly associated with worse EFS and correlated with post-treatment Deauville scores. In multivariable analysis, interim MTV 2.5 > 0 ml (adj. hazard ratio, HR: 3.89, p = 0.009) and interim TLG 41% ≥ 30 g (adj. HR: 7.98, p = 0.006) were independent risk factors for EFS.

CONCLUSION

Baseline and interim [18F]FDG PET parameters can serve as significant prognostic indicators for EFS and treatment response in pediatric HL. These quantitative measures could enhance individualized, risk-adapted treatment strategies for children and adolescents with HL.

Prognostic model using 18F-FDG PET radiomics predicts progression-free survival in relapsed/refractory Hodgkin lymphoma

Investigating prognostic factors in patients with relapsed or primary refractory classical Hodgkin lymphoma (R/R cHL) is essential to optimize risk-adapted treatment strategies. We built a prognostic model using baseline quantitative 18F-fluorodeoxyglucose positron emission tomography (PET) radiomics features and clinical characteristics to predict the progression-free survival (PFS) among patients with R/R cHL treated with salvage chemotherapy followed by autologous stem cell transplantation. Metabolic tumor volume and several novel radiomics dissemination features, representing interlesional differences in distance, volume, and standard uptake value, were extracted from the baseline PET. Machine learning using backward selection and logistic regression were applied to develop and train the model on a total of 113 patients from 2 clinical trials. The model was validated on an independent external cohort of 69 patients. In addition, we validated 4 different PET segmentation methods to calculate radiomics features. We identified a subset of patients at high risk for progression with significant inferior 3-year PFS outcomes of 38.1% vs 88.4% for patients in the low-risk group in the training cohort (P < .001) and 38.5% vs 75.0% in the validation cohort (P = .015), respectively. The overall survival was also significantly better in the low-risk group (P = .022 and P < .001). We provide a formula to calculate a risk score for individual patients based on the model. In conclusion, we developed a prognostic model for PFS combining radiomics and clinical features in a large cohort of patients with R/R cHL. This model calculates a PET-based risk profile and can be applied to develop risk-stratified treatment strategies for patients with R/R cHL. These trials were registered at www.clinicaltrials.gov as #NCT02280993, #NCT00255723, and #NCT01508312.

Children's Oncology Group's 2023 blueprint for research: Hodgkin lymphoma

The goal of therapy in pediatric Hodgkin lymphoma (HL) is to maximize overall survival while minimizing the morbidity of curative therapy. Key findings from recent Children's Oncology Group (COG) trials include: (i) superior event-free survival with the addition of brentuximab vedotin (Bv) in frontline regimens for high-risk disease, (ii) successful reduction in myeloablative regimens with demonstrated safety and efficacy of Bv and checkpoint inhibitor therapy in relapsed disease, and (ii) the potential to select a population that can be salvaged after relapse without receiving a stem cell transplant. The COG HL committee will lead a National cancer Institute National Clinical Trials Network phase 3 trial to evaluate the combination of Bv/nivolumab in early-stage disease. Ongoing advances in technology and blood biomarkers are increasing the ability to deliver biologically driven, personalized treatment for HL.

Imaging recommendations in pediatric lymphoma: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) are both malignancies originating in the lymphatic system and both affect children, but many features differ considerably, impacting workup and management. This paper provides consensus-based imaging recommendations for evaluation of patients with HL and NHL at diagnosis and response assessment for both interim and end of therapy (follow-up).

Baseline metabolic tumour burden improves risk stratification in Hodgkin lymphoma: A Children's Oncology Group study

The Children's Oncology Group AHOD0831 study used a positron emission tomography (PET) response-adapted approach in high-risk Hodgkin lymphoma, whereby slow early responders (SERs) received more intensive therapy than rapid early responders (RERs). We explored if baseline PET-based characteristics would improve risk stratification. Of 166 patients enrolled in the COG AHOD0831 study, 94 (57%) had baseline PET scans evaluable for quantitative analysis. For these patients, total body metabolic tumour volume (MTV), total lesion glycolysis (TLG), maximum standardized uptake value (SUVmax ) and peak SUV (SUVpeak ) were obtained. MTV/TLG thresholds were an SUV of 2.5 (MTV2.5 /TLG2.5 ) and 40% of the tumour SUVmax (MTV40% /TLG40% ). TLG2.5 was associated with event-free survival (EFS) in the complete cohort (p = 0.04) and in RERs (p = 0.01), but not in SERs (p = 0.8). The Youden index cut-off for TLG2.5 was 1841. Four-year EFS was 92% for RER/TLG2.5  up to 1841, 60% for RER/TLG2.5  greater than 1841, 74% for SER/TLG2.5  up to 1841 and 79% for SER/TLG2.5  greater than 1841. Second EFS for RER/TLG2.5  up to 1841 was 100%. Thus, RERs with a low baseline TLG2.5 experienced excellent EFS with less intensive therapy, whereas RERs with a high baseline TLG2.5 experienced poor EFS. These findings suggest that patients with a high upfront tumour burden may benefit from intensified therapy, even if they achieve a RER.

Diagnosis and management of Hodgkin lymphoma in children, adolescents, and young adults

Advances in the management of Hodgkin lymphoma in children, adolescents and young adult have resulted in survival outcomes exceeding 90%. The risk of late toxicity, however, remains a significant concern for survivors of HL and the focus of modern trials have been to advance cure rates while reducing long term toxicity. This has been accomplished through response-adapted treatment approaches and the incorporation of novel agents, many of which target the unique interaction between the Hodgkin and Reed Sternberg cells and the tumor microenvironment. In addition, an improved understanding of prognostic markers, risk stratification, and the biology of this entity in children and AYAs may allow us to further tailor therapy. This review focuses on the current management of HL in the upfront and relapsed settings, recent advances in novel agents that target HL and the tumor microenvironment, and promising prognostic markers that may help guide the future management of HL.

Nomogram model and risk score predicting overall survival and guiding clinical decision in patients with Hodgkin's lymphoma: an observational study using SEER population-based data

INTRODUCTION

This study developed a prognostic nomogram of Hodgkin lymphoma (HL) for purpose of discussing independent risk factors for HL patients with Surveillance, Epidemiology and End Results (SEER) database.

METHODS

We collected data of HL patients from 2010 to 2015 from the SEER database and divided it into two cohorts: the training and the verification cohort. Then the univariate and the multivariate Cox regression analyses were conducted in the training, the verification as well as the total cohort, after which the intersection of variables with statistical significance was taken as independent risk factors to establish the nomogram. The predictive ability of the nomogram was validated by the Concordance Index. Additionally, the calibration curve and receiver operating characteristic curve were implemented to evaluate the accuracy and discrimination. Finally, we obtained 1-year, 3-year and 5-year survival rates of HL patients.

RESULTS

10 912 patients were eligible for the study. We discovered that Derived American Joint Committee on Cancer (AJCC) Stage Group, lymphoma subtype, radiotherapy and chemotherapy were four independent risk factors affecting the prognosis of HL patients. The 1-year, 3-year and 5-year survival rates for high-risk patients were 85.4%, 79.9% and 76.0%, respectively. It was confirmed that patients with stage I or II had a better prognosis. Radiotherapy and chemotherapy had a positive impact on HL outcomes. However, patients with lymphocyte-depleted HL were of poor prognosis.

CONCLUSIONS

The nomogram we constructed could better predict the prognosis of patients with HL. Patients with HL had good long-term outcomes but novel therapies are still in need for fewer complications.

Clinical Perspectives for 18F-FDG PET Imaging in Pediatric Oncology: Μetabolic Tumor Volume and Radiomics

Pediatric cancer, although rare, requires the most optimized treatment approach to obtain high survival rates and minimize serious long-term side effects in early adulthood. 18F-FDG PET/CT is most helpful and widely used in staging, recurrence detection, and response assessment in pediatric oncology. The well-known 18F-FDG PET metabolic indices of metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) have already revealed an independent significant prognostic value for survival in oncologic patients, although the corresponding cut-off values remain study-dependent and not validated for use in clinical practice. Advanced tumor “radiomic” analysis sheds new light into these indices. Numerous patterns of texture 18F-FDG uptake features can be extracted from segmented PET tumor images due to new powerful computational systems supporting complex “deep learning” algorithms. This high number of “quantitative” tumor imaging data, although not decrypted in their majority and once standardized for the different imaging systems and segmentation methods, could be used for the development of new “clinical” models for specific cancer types and, more interestingly, for specific age groups. In addition, data from novel techniques of tumor genome analysis could reveal new genes as biomarkers for prognosis and/or targeted therapies in childhood malignancies. Therefore, this ever-growing information of “radiogenomics”, in which the underlying tumor “genetic profile” could be expressed in the tumor-imaging signature of “radiomics”, possibly represents the next model for precision medicine in pediatric cancer management. This paper reviews 18F-FDG PET image segmentation methods as applied to pediatric sarcomas and lymphomas and summarizes reported findings on the values of metabolic and radiomic features in the assessment of these pediatric tumors.