Online

ESTRO 2020

Session Item

Poster highlights 9 CL: Lung
8080
Poster Highlights
Clinical
09:17 - 09:25
Quality of surgery and RT in stage IIIN2 NSCLC: Insights from the Lung Adjuvant Radiotherapy trial
Yasmina Moukasse, France
PH-0280

Abstract

Quality of surgery and RT in stage IIIN2 NSCLC: Insights from the Lung Adjuvant Radiotherapy trial
Authors: Aurélie Bardet.(Gustave Roussy Institute, Biostatistics, Villejuif, France), John Edwards.(Northern General Hospital, Thoracic Surgery, Sheffield, United Kingdom), Corinne Faivre-Finn.(The Christie NHS Foundation Trust, Radiation Oncology, Manchester, United Kingdom), Cécile Le Pechoux.(Gustave Roussy Institute, Radiation Oncology, Villejuif, France), Delphine Lerouge.(François Baclesse Center, Radiation Oncology, Caen, France), Yasmina MOUKASSE.(Gustave Roussy Institute, Radiation Oncology, Villejuif, France), Nicolas Pourel.(Sainte Catherine Institute, Radiation Oncology, avignon, France), Sara Ramella .(Campus Bio-Medico University Hospital, Radiation Oncology, Roma, Italy), Ramon Rami-Porta.(Hospital Universitari Mutua Terrassa- and Ciberes Lung Cancer Group, Thoracic Surgery, Terrassa, Spain), Pascal-Alexandre Thomas.(North University Hospital- Aix-Marseille University & Hospitals, Thoracic Surgery, Marseille, France), Paul Van Schil.(University Hospital of Antwerp, Thoracic and Vascular Surgery, Antwerp, Belgium)
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Purpose or Objective

The objective of the phase III Lung Adjuvant Radiotherapy Trial (LungART) is to determine if modern conformal mediastinal postoperative radiotherapy (PORT), adapted to tumor location and involved lymph nodes (LN), can improve disease-free survival (DFS) for completely resected stage III N2 non-small-cell lung cancer (NSCLC) patients (pts). Given the potential toxicity of PORT in older randomized trials, it is crucial to investigate the quality assurance (QA) of both surgery and radiotherapy (RT).

Material and Methods

First, a surgical advisory committee composed of 4 expert thoracic surgeons reviews anonymized surgical and pathological reports, and establishes the quality of tumor resection and nodal exploration, taking into consideration the international guidelines. Then, for the RT QA analyses, RT advisory committee composed of 4 expert thoracic radiation oncologists, reassesses dosimetric plans of each patient treated in the PORT arm and correlates nodal target coverage with surgical data.

Results

In June 2019, from 252 patients treated in PORT arm, 142 files have already been analyzed for surgical and RT QA. The basic characteristics are specified in the following table:

Nodal dissection was performed according to lobar specific recommendations in most pts (see figure). Thirty-six pts (25%) had sampling 36 (25%), 32 (23%) a selective dissection and 73 (51%) a systematic dissection (1 patient was not evaluated). Even if all pts had a theoretical R0 resection, after revision, R0 resection was confirmed in 41 pts (29%), but the resection was uncertain in 58 (40.8%), microscopically incomplete (R1) in 42 (29.5%), and macroscopically incomplete (R2) in 1 pts (0.7%). For the RT QA, 87% of the radiotherapy treatment plans were adequate, and 13% (19) had major deviations including dose to the target volume (53%) and dose constraints to the heart (37%). The recommended target volume in the LungART trial depended on the primary tumor location and the involved LN stations. Ninety-seven (68%) of treatment plans had adequate mediastinal coverage, 34 (24%) too large coverage and 6 (8%) was marginally covered. Among the 142 pts analyzed, ipsilateral stations 4 and 10, and station 7 were included in 134 (94%) of cases. The involved and irradiated stations are demonstrated in the following figure: 

Conclusion

QA results of the LungART trial demonstrated high compliance with the protocol. Future LungART data will provide insights on the relationship between RT QA and clinical outcomes and better definition of the clinical target volume (CTV) after analysis of patterns of locoregional recurrence.