ESTRO 2022

Session Item

Saturday

May 07

10:30 - 11:30

Room D1

Upper GI

Co-Chair: , France;

Chair: , Austria

Session Code: 1230

Session Type: Proffered Papers

Track: Clinical

10:40 - 10:50

Impact of the Radiation Therapy Quality Assurance in the phase II/III CONCORDE trial.

Hugo LOPEZ, France

Presentation Number: OC-0108

Abstract

Abstract Title:

Impact of the Radiation Therapy Quality Assurance in the phase II/III CONCORDE trial.

Authors:

Hugo LOPEZ¹, Gilles Créhange², Julie Blanc³, Che M'vondo⁴, Renata Pereira⁵, Emmanuel Rio⁶, Didier Peiffert⁷, Kemara Gnep⁸, Karen Benezery⁹, Philippe Ronchin¹⁰, Georges Noel¹¹, Laurent Mineur¹², Antoine Drouillard¹³, Magali Rouffiac¹⁴, Jihane Boustani¹⁵, Aurélie Bertaut¹⁶, Florence Huguet¹

¹Tenon Hospital, Radiation Oncology, Paris, France; ²Institut Curie, Radiation Oncology, Paris, France; ³Centre Georges François Leclerc, Biostatistic, Dijon, France; ⁴Centre François Baclesse, Radiation Oncology, Caen, France; ⁵Centre Guillaume Le Conquérant, Radiation Oncology, Le Havre, France; ⁶Institut de Cancérologie de l’Ouest, Radiation Oncology, Saint-Herblain, France; ⁷Institut de Cancérologie de Lorraine, Radiation Oncology, Nancy, France; ⁸Centre Eugène Marquis, Radiation Oncology, Rennes, France; ⁹Centre Hospitalier Princesse Grace, Radiation Oncology, Monaco, Monaco; ¹⁰Clinique Plein Ciel, Radiation Oncology, Mougins, France; ¹¹Institut de cancérologie Strasbourg Europe, Radiation Oncology, Strasbourg, France; ¹²Institut Sainte Catherine, Radiation Oncology, Avignon, France; ¹³Centre Hospitalo Universitaire, Radiation Oncology, Dijon, France; ¹⁴Centre Georges François Leclerc, Radiation Oncology, Dijon, France; ¹⁵CHRU Jean Minjoz, Radiation Oncology, Besançon, France; ¹⁶Centre Georges François Leclerc , Biostatistic, Dijon, France

Show Affiliations

Purpose or Objective

The CONCORDE phase 2-3 trial assessed the benefit of radiation therapy dose escalation in locally advanced esophageal cancer patients that cannot undergo surgery. This planned analysis investigated the adherence to the radiation therapy protocol and its impact on the clinical outcomes as part of the quality assurance of the trial.

Material and Methods

The trial’s radiation therapy quality assurance (RTQA) protocol included written guidelines on how to deliver radiation therapy. We analyzed each patient’s delineation, dose-volume histogram, and treatment administration. Adherence to protocol was classified as: per protocol (PP), acceptable minor deviation (MiD), or unacceptable major deviation (MaD). The impact of protocol deviations on overall survival (OS), progression-free survival (PFS), acute toxicities, and late toxicities was studied.

Results

Among the 217 patients included, 181 case reviews (83.4%) were assessed: 28 patients were classified PP (15.5%), 70 MiD (38.7%), and 83 MaD (45.8%). Patients with tumors longer than 5 cm had significantly more MaD than the others (p= 0.0032). There was significantly more MaD in the escalated dose arm than in the standard arm (53.9% vs. 38%, p=0.03). In the dose escalated arm, there was significantly more MaD regarding PTV coverage (15.7% vs 6.5% p=0.04) and more patients not receiving the prescribed RT dose than in the control arm (11.2% vs 6.5%, p=0.08). Among patients treated with 3DCRT, none were classified as PP and the rate of patients with MaD was higher than with IMRT (60% vs 42.5%, p=0.06). Also, there was significantly more MaD regarding PTV coverage (67% vs 37%, p=0.001), and the heart volume receiving 40 Gy (11.4% vs. 2.1%, p=0.02). The median OS was significantly higher in the PP + MiD group than in the MaD group (42 months vs. 18.4 months; HR = 1.66 [CI95%, 1.12 - 2.47]; p=0.01). When patients with MaD were excluded, median PFS was not statistically different between patients in the dose escalated arm and patients in the standard arm (12 months vs. 16.4 months; HR = 1.35 [CI95%, 0.82-2.23]; p=0.2). Patients with MaD experienced more acute toxicities, especially radiation pneumonitis (p=0.04), and significantly more non-hematological late toxicities (p=0.027).

Overall survival of patients depending on the protocol deviations

Conclusion

Patients included in CONCORDE trial with major protocol deviations had a reduced survival and increased toxicities. RTQA remains therefore essential in clinical trials. In the subgroup of patients treated per protocol or with minor deviations only, dose escalation did not appear to improve survival in esophageal cancer patients treated with exclusive CRT.