Dose volume effects of re‐irradiation for locally recurrent nasopharyngeal carcinoma

• Published in: Head & neck Vol. 42; no. 2; pp. 180 - 187
• Main Authors: Ng, Wai‐Tong, Lee, Michael CH, Fung, Nelson TC, Wong, Edwin CY, Cheung, Alice KW, Chow, James CH, Au, Kwok‐Hung, Poon, Darren MC, Lai, Jessica WY, Chiang, Chi‐Leung, Choi, Horace CW, Chau, Tin‐Ching, Lee, Victor HF, Lee, Anne WM
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-02-2020; Wiley Subscription Services, Inc
• Subjects: Head and neck; local recurrence; Nasopharyngeal carcinoma; Radiation; re‐irradiation; salvage; Survival; Throat cancer; toxicities; Tumors; toxicities; nasopharyngeal carcinoma; local recurrence; re-irradiation; salvage
• ISSN: 1043-3074; 1097-0347
• DOI: 10.1002/hed.25988

Background
This study analyzed the dose volume effects of re‐irradiation for locally recurrent nasopharyngeal carcinoma (NPC) and attempts to determine the optimal dose for the best survival.
Methods
Ninety‐one patients were studied. The local control, fatal complication, and overall survival were analyzed against the dose (in Equivalent Dose at 2 Gy/fractions) and recurrent gross tumor volume (GTV).
Results
The local control and fatal complication rate appear to increase with prescribed dose. The overall survival peaks at around 60 Gy10. Local control decreases significantly with increasing GTV (P < .001) while overall survival shows similar trend (P = .06). No correlation was observed between the fatal complication rate and GTV volume. The dose response of local control appears to be stronger for smaller tumors.
Conclusion
GTV volume plays a significant role in local control. A 60 Gy10 appears to be optimal for the best survival outcome; higher doses might be considered for small tumors.