Pretherapeutic FDG-PET total metabolic tumor volume predicts response to induction therapy in pediatric Hodgkin's lymphoma.

Abstract

BACKGROUND:

Standardized treatment in pediatric patients with Hodgkin's lymphoma (HL) follows risk stratification by tumor stage, erythrocyte sedimentation rate and tumor bulk. We aimed to identify quantitative parameters from pretherapeutic FDG-PET to assist prediction of response to induction chemotherapy.

METHODS:

Retrospective analysis in 50 children with HL (f:18; m:32; median age, 14.8 [4-18] a) consecutively treated according to EuroNet-PHL-C1 (n = 42) or -C2 treatment protocol (n = 8). Total metabolic tumor volume (MTV) in pretherapeutic FDG-PET was defined using a semi-automated, background-adapted threshold. Metabolic (SUVmax, SUVmean, SUVpeak, total lesion glycolysis [MTV*SUVmean]) and heterogeneity parameters (asphericity [ASP], entropy, contrast, local homogeneity, energy, and cumulative SUV-volume histograms) were derived. Early response assessment (ERA) was performed after 2 cycles of induction chemotherapy according to treatment protocol and verified by reference rating. Prediction of inadequate response (IR) in ERA was based on ROC analysis separated by stage I/II (1 and 26 patients) and stage III/IV disease (7 and 16 patients) or treatment group/level (TG/TL) 1 to 3.

RESULTS:

IR was seen in 28/50 patients (TG/TL 1, 6/12 patients; TG/TL 2, 10/17; TG/TL 3, 12/21). Among all PET parameters, MTV best predicted IR; ASP was the best heterogeneity parameter. AUC of MTV was 0.84 (95%-confidence interval, 0.69-0.99) in stage I/II and 0.86 (0.7-1.0) in stage III/IV. In patients of TG/TL 1, AUC of MTV was 0.92 (0.74-1.0); in TG/TL 2 0.71 (0.44-0.99), and in TG/TL 3 0.85 (0.69-1.0). Patients with high vs. low MTV had IR in 86 vs. 0% in TG/TL 1, 80 vs. 29% in TG/TL 2, and 90 vs. 27% in TG/TL 3 (cut-off, > 80 ml, > 160 ml, > 410 ml).

CONCLUSIONS:

In this explorative study, high total MTV best predicted inadequate response to induction therapy in pediatric HL of all pretherapeutic FDG-PET parameters - in both low and high stages as well as the 3 different TG/TL.

TRIAL REGISTRATION:

Ethics committee number: EA2/151/16 (retrospectively registered).

• Authors: Julian M M Rogasch, Patrick Hundsdoerfer, Frank Hofheinz, Florian Wedel, Imke Schatka, Holger Amthauer, Christian Furth
• Journal: BMC cancer (BMC Cancer) Vol. 18 Issue 1 Pg. 521 (May 03 2018) ISSN: 1471-2407 [Electronic] England
• PMID: 29724189 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Radiopharmaceuticals
• Fluorodeoxyglucose F18

Topics

• Adolescent
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Child
• Child, Preschool
• Female
• Fluorodeoxyglucose F18 (administration & dosage)
• Hodgkin Disease (diagnostic imaging, drug therapy, pathology)
• Humans
• Induction Chemotherapy
• Male
• Neoplasm Staging
• Positron-Emission Tomography (methods)
• Radiopharmaceuticals (administration & dosage)
• Retrospective Studies
• Treatment Outcome
• Tumor Burden