Involved site radiation therapy in stage I-III nasopharyngeal carcinoma with limited lymph node burden (ISRT-NPC) or elective region irradiation: a study protocol for a multicenter non-inferiority randomized controlled phase III clinical trial.

Abstract

BACKGROUND:

Current radiotherapy guidelines and consensus statements uniformly recommend elective region irradiation (ERI) as the standard strategy for nasopharyngeal carcinoma (NPC). However, given the scarcity of skip-metastasis, the improved assessment accuracy of nodal involvement, and the striking advancements in chemotherapy for NPC, a one-fits-all delineation scheme for clinical target volumes of the nodal region (CTVn) may not be appropriate anymore, and modifications of the CTVn delineation strategy may be warranted. Involved site irradiation (ISI) covering merely the initially involved nodal site and potential extranodal extension has been confirmed to be as effective as ERI with decreased radiation-related toxicities in some malignancies, but has not yet been investigated in NPC. This study aims to compare the regional control, survival outcomes, radiation-related toxicities, and quality of life (QoL) of ISI with conventional ERI in NPC patients with a limited nodal burden.

METHODS:

ISRT-NPC is a prospective, multicenter, open-label, noninferiority, phase III randomized controlled trial. A total of 414 patients will be randomly assigned in a 1:1 ratio to receive ISI or ERI. Randomization will be stratified by institution scale and N stage. Generally, in the ISI group, the high-risk CTV1 (dose: 60 Gy) includes a 1-cm expansion of the positive LN as well as the VIIa and the retrostyloid space above the bilateral transverse process of the atlantoaxial spine (C1), regardless of N status. The low-risk CTV2 (dose: 50 Gy) covers the cervical nodal region with a 3-cm caudal expansion below the transverse process of C1 for N0 disease and a 3-cm expansion below the positive LN for positive LNs.

DISCUSSION:

The results of this trial are expected to confirm that ISI is a non-inferior strategy to ERI in stage I-III patients with low LN burden, enabling the minimization of treatment-related toxicity and improvement of long-term QoL without compromising regional control.

TRIAL REGISTRATION:

ClinicalTrails.gov, NCT05145660. Registered December 6, 2021.

• Authors: Yang Liu, Yaqian Han, Feng Liu, Desheng Hu, Zhijian Chen, Peiguo Wang, Jingao Li, Jiyong Qin, Feng Jin, Yexiong Li, Jingbo Wang, Junlin Yi
• Journal: BMC cancer (BMC Cancer) Vol. 23 Issue 1 Pg. 724 (Aug 03 2023) ISSN: 1471-2407 [Electronic] England
• PMID: 37537541 (Publication Type: Clinical Trial Protocol, Journal Article)
• Copyright: © 2023. BioMed Central Ltd., part of Springer Nature.

Topics

• Humans
• Nasopharyngeal Carcinoma (radiotherapy, pathology)
• Quality of Life
• Nasopharyngeal Neoplasms (pathology)
• Prospective Studies
• Lymphatic Metastasis (radiotherapy, pathology)
• Lymph Nodes (pathology)
• Randomized Controlled Trials as Topic
• Multicenter Studies as Topic
• Clinical Trials, Phase III as Topic