Madrid, Spain
Onsite/Online

ESTRO 2021

Session Item

Sunday
August 29
16:45 - 17:45
Online Stream 2
Poster highlights 17: Gynaecological
Kathrin Kirchheiner, Austria
1820
Poster highlights
Clinical
11:40 - 11:50
Dose-painting multicenter phase III trial in newly diagnosed glioblastoma: the SPECTRO-GLIO trial
Anne Laprie, France
OC-0333

Abstract

Dose-painting multicenter phase III trial in newly diagnosed glioblastoma: the SPECTRO-GLIO trial
Authors:

Anne LAPRIE1, Georges Noel2, Leonor Chaltiel3, Gilles Truc4, Marie-PIerre Sunyach5, Marie Charissoux6, Nicolas Magné7, PIerre Auberdiac8, Soléakhéna Ken9, Franck Roux10, Laure Vieillevigne9, Fatima Tensaouti11, Isabelle Catalaa12, Sergio Boetto10, Emmanuelle Uro-Coste13, Stéphane Supiot14, Valérie Bernier15, Thomas Filleron16, Muriel Mounier17, Muriel Poublanc17, Jean-Pierre Delord18, Elizabeth Cohen-Jonathan-Moyal11

1ICR - IUCT-oncopole, Radiation Oncology, Toulouse, France; 2ICANS, Radiation Oncology, Strasbourg, France; 3ICR - IUCT-oncopole, Biostatistics, Toulouse, France; 4Centre Georges-François Leclerc , Radiation Oncology, DIJON, France; 5Centre léon Berard, Radiation Oncology, Lyon, France; 6ICM, Radiation Oncology, Montpellier, France; 7Institut de Cancérologie de la Loire, Radiation Oncology, Saint-Priest en Jarez , France; 8Clinique Claude Bernard, Radiation Oncology, Albi, France; 9ICR-IUCT-oncopole, Radiophysics, Toulouse, France; 10CHU de Toulouse, Neurosurgery, Toulouse, France; 11ICR-IUCT-oncopole, Radiation Oncology, Toulouse, France; 12CHU de Toulouse, Radiology, Toulouse, France; 13CHU-IUCT-oncopole, Pathology, Toulouse, France; 14ICO, Radiation Oncology, Nantes, France; 15ICL- CAV, Radiation Oncology, Vandoeuvres-les-Nancy, France; 16ICR-IUCT-oncopole, Biostatistics, Toulouse, France; 17ICR-IUCT-oncopole, Clinical Research Office, Toulouse, France; 18ICR-IUCT-oncopole, Medical Oncology, Toulouse, France

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Purpose or Objective

Glioblastoma, a high-grade glial infiltrating tumor, is the most frequent malignant brain tumor in adults and carries a dismal prognosis. External beam radiotherapy (EBRT) increases overall survival but this is still low due to local relapses, mostly occurring in the irradiation field. As the ratio of spectra of choline/N acetyl aspartate> 2 (CNR2) on MR spectroscopic imaging has been described as predictive for the site of local relapse, we hypothesized that dose escalation on these regions would increase local control and survival[1].

Material and Methods

In this multicenter prospective phase III trial for newly diagnosed glioblastoma, 180 patients having undergone biopsy or surgery were randomized to 2 arms. Arm A was the Stupp protocol (EBRT 60 Gy on contrast enhancement + 2 cm margin with concomitant temozolomide (TMZ) and six months of TMZ maintenance).  Arm B was the same treatment with an additional simultaneous integrated boost of intensity-modulated radiotherapy (IMRT) of 72Gy/2.4Gy delivered on the MR spectroscopic imaging metabolic volumes of CHO/NAA>2 and contrast-enhancing lesions or resection cavity. Stratification was performed on surgical (biopsy versus surgery) and MGMT status. An online prospective quality control (QC) of volumes and dose was performed in the experimental arm. The main objective was overall survival, estimated by the Kaplan-Meier method in each randomization arm and compared by the Logrank test, as well as by the Cox model adjusted on the stratification factors and on the already known prognostic factors.

Results

There was no significant difference between the 2 groups regarding characteristics: gender; age median age, weight, PS, 46% were MGMT unmethylated, 85% were surgically resected.

Initial tumors were more frequently <30mm diameter in arm A (36% vs 27%) (p=0.0316).

General, neurological and hematological secondary effects were comparable between the 2 arms, except more frequent grade 1-2 cephalalgia in arm A(59.1% vs 42.9%,p= 0.0075) and more frequent grade 1-2 neurological deficit in Arm B ( 45.7% vs 35.4%,p=0.0043). After a median follow-up of 43.7 Months (95% IC [35.8; 45.8]), no statistical difference between arms were observed for OS  (HR=0.90 [0.64;1.27], p=0.5526)) and PFS (HR=1.09 [0.80;1.48], p = 0.6027). Overall survival (OS) and Progression Free Survival ( PFS)  were comparable between arm A and B, respectively  OS 22.6 months versus 22.2 months (p=0.55) and PFS  8.6 vs 7.8 months (p=0.6) 

Conclusion

In this dose-painting trial, i.e. delivery of heterogeneous dose guided by metabolic imaging, dose increase was well tolerated. Overall survival was not improved. This study yields a large amount of longitudinal multimodal MR imaging data including planning CT, radiotherapy dosimetry, MR spectroscopic, diffusion and perfusion imaging to participate in the efforts in deciphering the pathways of pseudoprogression and radioresistance of glioblastoma.

Trial registration: NCT01507506

 

[1] : Laprie et al, BMC Cancer 2019 Feb 21;19(1):167.