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
2108 - Biomarker analyses of ramucirumab in patients with platinum refractory urothelial cancer from RANGE, a global, randomized, double-blind, phase 3 study.
Presenter: Michiel Van der Heijden
Session: Poster Display session 3
Resources:
Abstract
3090 - Comparison of Immuno-Oncology (IO) Biomarkers in Adenocarcinoma (ACB), Urothelial Carcinoma (UCB) and Squamous Cell Carcinoma (SCCB) of the Bladder, with interim results from PURE01
Presenter: Daniele Raggi
Session: Poster Display session 3
Resources:
Abstract
5211 - Potential role of a clinical, taxonomical classification and RNA expression integrated signature to predict response to neoadjuvant platinum-based chemotherapy in muscle-invasive bladder cancer (MIBC) patients
Presenter: Albert Font
Session: Poster Display session 3
Resources:
Abstract
3206 - Hyperphosphatemia due to Erdafitinib (a Pan-FGFR Inhibitor) and Anti-tumor Activity Among Patients (Pts) with Advanced Urothelial Carcinoma (UC)
Presenter: Scott Tagawa
Session: Poster Display session 3
Resources:
Abstract
3110 - Prognostic role of FGFR Mutations and FGFR mRNA expression in metastatic urothelial cancer treated with anti-PD(L1) inhibitors in first and second line setting
Presenter: Florian Roghmann
Session: Poster Display session 3
Resources:
Abstract
3564 - Circulating tumour DNA (ctDNA) utility as a biomarker for metastatic urothelial carcinoma (mUC)
Presenter: Jean-Michel Lavoie
Session: Poster Display session 3
Resources:
Abstract
2760 - Comparative analysis of tumor mutational burden (TMB) prediction methods and its association with determinants of the tumor immune microenvironment of urothelial bladder cancer (UBC)
Presenter: Markus Eckstein
Session: Poster Display session 3
Resources:
Abstract
2513 - The Immunoscore in patients with urothelial carcinoma treated with neoadjuvant chemotherapy: clinical significance for pathological response and survival
Presenter: Elise Nassif
Session: Poster Display session 3
Resources:
Abstract
2835 - Genomic analysis of urothelial cancer and associations with treatment choice and outcome
Presenter: David Sarid
Session: Poster Display session 3
Resources:
Abstract
5763 - cfDNA is an acceptable but insufficient means of characterizing FGFR3 mutation in patients with metastatic urothelial cancer (mUC)
Presenter: Sumanta Pal
Session: Poster Display session 3
Resources:
Abstract