Abstract 1564
Background
Intensity modulated radiation therapy (IMRT) is the standard of care for nasopharyngeal carcinoma (NPC). Part of the IMRT quality assurance process involves accurate target volume delineation, which is crucial for local control and survival. Current practice utilizes a uniform contouring method for clinical target volume (CTV) for all stages of NPC. Here, we conducted a single-arm phase 2 trial investigating the tumor control rates of reduced CTV margins and corresponding doses in low-risk, early-stage NPC.
Methods
Patients with biopsy-proven stage I-IIb (6th UICC/AJCC) NPC were enrolled. All patients were treated with IMRT alone. Two CTVs (CTV1 [high risk] and CTV2 [low risk]) were outlined; CTV1 was defined by grossly identified tumour (on MRI or CT) plus 5-mm margin (3-mm posteriorly); CTV2 was CTV1 plus 5-mm margin (3-mm posteriorly). 60 Gy and 50–54 Gy in 30 fractions were prescribed to CTV1 and CTV2, respectively. Primary end-point was locoregional recurrence free survival (LRRFS).
Results
From May 2001 to August 2006, 103 patients were recruited; all patients completed IMRT as planned (time duration 39-61 days). At a median follow-up of 12.6 years, five patients developed locoregional failures; of which one was in-field, and four were regional recurrence (two in-field and two marginal). 10-year LRRFS, distant metastasis free survival (DMFS), disease specific survival (DSS) and overall survival (OS) were 95.0% and 94.1%, 94.0% and 91.1%, respectively. The most common grade 1-2 late toxicities included subcutaneous fibrosis (79.6%), hearing loss (53.4%) and skin dystrophy (43.2%); grade 3 included subcutaneous fibrosis (2.9%) and hearing loss (2.9%); and no grade 4 late toxicity.
Conclusions
Reduced CTV margins and corresponding doses results in optimal long-term tumour control, with minimal late adverse events.
Clinical trial identification
NCT03839602.
Editorial acknowledgement
Legal entity responsible for the study
Chong Zhao.
Funding
National Natural Science Foundation of China [No. 81872469]; Science and Technology Project of Guangdong Province [No. 2014A020212433].
Disclosure
M.L.K. Chua: Honoraria (institution), Advisory / Consultancy: Janssen, Astellas, Varian, Ferring Singapore and AstraZeneca; Research grant / Funding (institution), Structured research agreement/Research funding - Ferring Singapore, GenomeDx Biosciences, Varian, MedLever.: Ferring Singapore, GenomeDx Biosciences, Varian, MedLever. All other authors have declared no conflicts of interest.
Resources from the same session
4868 - Evaluation of markers associated with efficacy of abiraterone acetate plus prednisone (AAP) in patients (pts) with castration-sensitive prostate cancer (mCSPC) from the LATITUDE study
Presenter: Kim Chi
Session: Poster Display session 3
Resources:
Abstract
4837 - LRP2, a potential new biomarker for Chinese younger aged intrahepatic cholangiocarcinoma patients
Presenter: Xiaoliang Shi
Session: Poster Display session 3
Resources:
Abstract
1286 - Reanalysis of the efficacy of molecular targeted agents (MTAs) given in the randomized trial SHIVA01 according to the ESMO ESCAT scale of actionability
Presenter: Aurelie Moreira
Session: Poster Display session 3
Resources:
Abstract
2736 - Comparison of Platforms for Determining Tumor Mutational Burden (TMB) From Blood Samples in Patients With Non-Small Cell Lung Cancer (NSCLC)
Presenter: Jonathan Baden
Session: Poster Display session 3
Resources:
Abstract
5045 - Comprehensive Pan-Cancer analysis of somatic mutations in drug transporters to reveal acquired and intrinsic drug resistance in 3149 metastatic cancer patients
Presenter: Sander Bins
Session: Poster Display session 3
Resources:
Abstract
4577 - Pan-Cancer Genomic Landscape of the Cyclin D1/FGF3,4,19 (11q13) Amplicon Including Associations with HPV Status, and ESR1 and AR Alterations
Presenter: Jennifer Johnson
Session: Poster Display session 3
Resources:
Abstract
5366 - Co-occurrence of NTRK fusions with other genomic biomarkers in cancer patients
Presenter: Xiaolong Jiao
Session: Poster Display session 3
Resources:
Abstract
4084 - Prospective comparative study of next-generation sequencing on fine needle aspirations versus core needle biopsies in cancer patients included in SHIVA02 trial
Presenter: Julien Masliah-Planchon
Session: Poster Display session 3
Resources:
Abstract
6017 - First national External Quality Assessement for the interpretation of somatic variants: assessment of 25 variants in colorectal, lung, ovarian cancers and melanoma in France
Presenter: Etienne Rouleau
Session: Poster Display session 3
Resources:
Abstract
2283 - Prospective testing of circulating tumor DNA in metastatic breast cancer facilitates clinical trial enrollment and precision oncology
Presenter: Andjelija Bujak
Session: Poster Display session 3
Resources:
Abstract