The effect of intensity-modulated radiotherapy versus conventional radiotherapy on quality of life in patients with nasopharyngeal cancer: A cross-sectional study

Abstract

Purpose: Previous reports suggested that dosimetric superiority of Intensity modulated radiotherapy (IMRT) over conventional radiotherapy(CRT) could translate into improved quality of life (QoL) for patients with nasopharyngeal carcinoma(NPC). However, such advantage has not been confirmed using NPC-specific questionnaire with long-term follow-up. The purpose of this cross-sectional study was to compare the changing tendency of QoL between patients received IMRT and CRT with different follow-up time using a NPC-specific QoL instrument, and further validate the advantage of IMRT in QoL of NPC patients. Methods: We developed a modified NPC-specific QoL questionnaire (NPCQLQ) which contains 35 items based on EORTC QLQ-30 in combination with NPC-specific side effects. One hundred and forty-two patients with localized NPC who were successfully treated defenitely without recurrence at the time of this analysis were enrolled and completed the questionnaire. Seventy-five patients were treated with IMRT and 67 received CRT. The median follow-up time was 25 months (range 12-42 months). Patients were divided into three sub-groups according to their different follow-up time: 12-18, 19-28 and 29-42 months after treatment, respectively. QoL of NPC patients was compared between different radiation techniques at three different follow-up intervals using Two Independent Samples Tests. K Independent Samples Tests was used to compared the changing tendency of IMRT vs. CRT with the prolongation of follow-up time. Results: At 12-18 months after treatment, all QoL scores of patients were comparable in both groups. At 19-28 months, a statistically significant improvement of QoL in symptom scales in the IMRT group was observed when compared to that of the CRT group (78.48±9.30 vs. 69.66±12.03, p=0.008). At 29-42 months, QoL scores of physical functioning scales, global health status and symptom scales were significantly superior in the IMRT group (90.72±9.87, 83.16±13.65 and 66.67±23.57, respectively) than those in the CRT group (50.00±31.47, 78.46±11.79 and 67.85±13.86, respectively). QoL scores in all the six scales of patients showed no significant change with prolonged follow-up time within the IMRT group. However, patients received CRT demonstrated a trend toward a declining QoL in physical functioning scales, global health status and symptom scales with longer follow up, but only the change of global health status reached a statistically significence (p=0.026). Conclusions: IMRT substantially improved QoL in NPC patients when compared to conventional radiotherapy, and the superiority become significant with prolonged follow-up time.