ESTRO 2024 - Abstract Book

S1459

Clinical - Head & neck

ESTRO 2024

[6] Deschuymer S, Nevens D, Duprez F, et al. Randomized clinical trial on reduction of radiotherapy dose to the elective neck in head and neck squamous cell carcinoma; update of the long-term tumor outcome. Radiother Oncol 2020;143:24 – 9.

3404

Proffered Paper

Radiotherapy alone versus concurrent chemoradiotherapy in nasopharyngeal carcinoma patients obtaining CR/PR after neoadjuvant chemotherapy: a randomized, multicenter, phase 3 trial

Ting Jin, Xiaozhong Chen

Zhejiang cancer hospital, Department of Radiation Oncology, Hangzhou, China

Purpose/Objective:

This study aims to compare the efficacy and toxicity of radiotherapy (RT) alone and concurrent chemoradiotherapy (CCRT) in nasopharyngeal carcinoma (NPC) patients obtaining complete or partial response (CR/PR) after neoadjuvant chemotherapy (NACT).

Material/Methods:

Patients who were newly diagnosed as staged III-IVb NPC and obtained CR/PR after NACT were included. All patients received 3 cycles of TP neoadjuvant chemotherapy at day 1, 22, and 43 with docetaxel 75mg/m 2 and cisplatin 75mg/m 2 . Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1 was used to evaluate treatment response. All subjects included were randomized to receive RT or CCRT. The concurrent chemotherapy regimen in the CCRT arm was 2 cycles of cisplatin at 100mg/m 2 . The primary endpoint was progress-free survival (PFS). Secondary endpoints included overall survival (OS) and adverse events.

Results:

Up to now, a total of 220 patients histologically diagnosed with NPC were enrolled in the study according to inclusion criteria, of which 109 patients were assigned to the RT arm and 111 patients were assigned to the CCRT arm. The median follow-up was 30 months (range 6 to 80 months). The 3-year LRFS, RRFS, LRRFS, DMFS, PFS, and OS were 95.9%, 95.6%, 96.5%, 98.2%, 91.0%, and 98.8% in the RT arm, compared with 97.8%, 91.2%, 86.8%, 88.2%, 73.9%, and 91.9% in the CCRT arm. No statistical difference for LRFS, RRFS, LRRFS, DMFS, PFS, or OS was observed between the two arms (p > 0.05). The incidence of grade 3-4 anemia (3.7% vs. 10.8%, p=0.041), thrombocytopenia (3.7% vs. 11.7%, p=0.026), neutropenia (6.4% vs. 23.4%, p<0.001), leukopenia (7.3% vs. 25.2%, p<0.001), stomatitis (14.7% vs. 29.7%, p=0.007), nausea (1.8% vs. 21.6%, p<0.001), vomiting (1.0% vs. 19.8%, p<0.001) were significantly lower in the RT arm than in the CCRT arm. The incidence of grade 1-2 deafness/otitis (50.5% vs. 65.8%, p=0.021), and liver dysfunction (9.2% vs. 23.4%, p=0.004) was lower in the RT arm as well.

Conclusion: