Long-term outcomes of replanning during intensity-modulated radiation therapy in patients with nasopharyngeal carcinoma: An updated and expanded retrospective analysis

Recent studies show that adaptive replanning for patients with nasopharyngeal carcinoma (NPC) during intensity-modulated radiation therapy (IMRT) improve the short-term local-regional recurrence-free survival (LRFS), and quality of life (QoL). We aimed to assess the long-term survival outcomes and QoL in patients with non-metastatic NPC who received IMRT with replanning compared to those who received IMRT without replanning.We conducted an updated and expanded retrospective analysis from an existing prospective cohort for non-metastatic NPC patients undergoing IMRT in our institution. Non-metastatic NPC patients receiving IMRT from June 2007 to December 2015 were consecutively enrolled based on electronic medical record. Patients who were still alive were eligible for the QoL study. The survival outcomes and QoL were compared between patients with and without replanning.Among 290 patients, 147 (50.7%) received IMRT without replanning and 143 (49.3%) received IMRT with replanning. Replanning group had a higher 8-year LRFS rate (87.4% vs. 75.6%, P = 0.025). However, 8-year overall survival rate was not statistically significant. Patients with replanning compared to those who without replanning had significant improvements in social functioning (P = 0.016), insomnia (P = 0.048), dry mouth (P = 0.004), and sticky saliva (P = 0.005). Additionally, the score of the role functioning was marginally higher in patients treated with IMRT replanning (P = 0.063).This extended follow-up study demonstrates the long-term security and validity for adaptive radiotherapy in IMRT for non-metastatic NPC patients. We highly recommend that adaptive replanning should be routinely implemented for non-metastatic NPC patients.