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
3988 - Basal NK activity and early Treg function inhibition predicts Nivolumab responsiveness in metastatic renal cancer patients (REVOLUTION) trial.
Presenter: Sara Santagata
Session: Poster Display session 3
Resources:
Abstract
2142 - Low NK Cell Abundance Correlates with High Expression of PD-1 in CD8+ T Cells
Presenter: Moon Hee Lee
Session: Poster Display session 3
Resources:
Abstract
5501 - Tobacco smoking is associated with the immune suppressive microenvironment in head and neck squamous cell carcinoma (HNSCC)
Presenter: Christine Chung
Session: Poster Display session 3
Resources:
Abstract
5726 - Evaluation of Antibody-Dependent Cell Cytotoxicity (ADCC) in lung cancer cell lines treated with combined anti-EGFR and anti-PD-L1 therapy.
Presenter: Francesca Sparano
Session: Poster Display session 3
Resources:
Abstract
2534 - Radiomic Signatures for Identification of Tumors Sensitive to Nivolumab or Docetaxel in Squamous Non-Small Cell Lung Cancer (sqNSCLC)
Presenter: Laurent Dercle
Session: Poster Display session 3
Resources:
Abstract
3366 - Analysis of gut microbiota in advanced non-small cell lung cancer (NSCLC) patients treated with immune-checkpoints blockers
Presenter: FEIYU ZHANG
Session: Poster Display session 3
Resources:
Abstract
2089 - Pathogenesis of Myocarditis Following Treatment with Immune Checkpoint Inhibitors in a Cynomolgus Monkey Model
Presenter: Changhua Ji
Session: Poster Display session 3
Resources:
Abstract
4463 - Effects of dietary restriction in cancer patients receiving irinotecan
Presenter: Ruben Van Eerden
Session: Poster Display session 3
Resources:
Abstract
4841 - Investigating the Link between Burn Injury and Tumorigenesis
Presenter: Lucy Barrett
Session: Poster Display session 3
Resources:
Abstract
4619 - Prognostic value of the neutrophil-lymphocyte, platelet-lymphocyte and monocyte-lymphocyte ratio in male breast cancer patients
Presenter: Joanna Huszno
Session: Poster Display session 3
Resources:
Abstract