Reirradiation for Recurrent Nasopharyngeal Carcinomas: Experience From an Academic Tertiary Center in a Low- to Middle-Income Country

Abstract

PURPOSE The objectives of this study were to report the oncologic outcomes and the treatment-related toxicities after reirradiation (re-RT) for recurrent nasopharyngeal carcinoma (rNPC) at our institution and to apply a recently published prognostic model for survival in rNPC in our cohort. PATIENTS AND METHODS Thirty-two patients with rNPC treated at the authors' institution with re-RT were retrospectively reviewed. Treatment modalities for re-RT were intensity-modulated radiotherapy (n = 14), three-dimensional conformal radiotherapy (n = 9), single-fraction stereotactic radiosurgery (n = 6), fractionated stereotactic radiotherapy (n = 2), and high dose rate intracavitary brachytherapy (n = 1). Twenty-seven patients received re-RT with curative intent, whereas five patients were treated palliatively. RESULTS Median follow-up time was 15.5 months (range, 1 to 123 months) for the entire cohort and 20 months (range, 3 to 123 months) for patients treated with curative intent. For the entire cohort, median locoregional recurrence-free survival (LRRFS) was 14 months, with actuarial 1- and 2-year LRRFS estimates of 67.5% and 44.0%, respectively. Median overall survival (OS) time was 38 months, with actuarial 1- and 2-year estimates of 74.2% and 57.2%, respectively. For patients treated with curative intent, median LRRFS was not reached. Actuarial 1- and 2-year LRRFS estimates were 68.2% and 54.5%, respectively. Median OS time after curative intent re-RT was 42 months, with actuarial 1- and 2-year estimates of 75.4% and 63.8%, respectively. One- and 2-year OS estimates based on risk stratification were 68.6% for high risk compared with 80.8% for low risk and 34.3% for high risk compared with 70.7% for low risk, respectively ( P = .223). Three patients (9.4%) developed symptomatic temporal lobe necrosis. There was no reported grade 5 treatment-related toxicity. CONCLUSION Results of the study suggest that re-RT is an effective and safe salvage treatment strategy for rNPC. Re-RT to a maximum equivalent dose in 2-Gy fractions of 60 Gy may yield good LRRFS and translate to prolonged OS.

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

“…As a result, the optimal RT dose appears to be approximately 60 Gy 10 at which the overall survival peaks. The detrimental effect of over‐aggressive second course of irradiation concurs with the observations by Leong et al and Agas et al…”

Recurrent Nasopharyngeal Cancer: Critical Review of Local Treatment Options Including Recommendations during the COVID-19 Pandemic

“…However, in a recent meta-analysis, the reported grade 5 toxicity (treatment-related death) following re-irradiation based on conventionally fractionated IMRT in patients with rNPC was 33% [72]. In contrast to that, the potential for long-term survival with re-IMRT has been demonstrated by several authors in a carefully selected subset of patients [17,19,20,37,[73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88].…”

“…Re-irradiation (overlap of the new radiation fields with the prior full-dose radiation volume) should be approached with caution in all cases, as there is a high risk of iatrogenic treatment-related morbidity and mortality [72]. Various techniques of re-irradiation have been proposed in this setting, including IMRT [17,19,20,37,[73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88], SRS [89][90][91], stereotactic body radiotherapy (SBRT) [91][92][93][94][95][96][97][98][99][100], proton beam therapy (PBT) [101][102][103], carbon ion radiation therapy (CIRT) [104][105][106][107][108][109], and intracavitary or interstitial brachytherapy (BRT) [110][111][112][113]…”

“…In wo series, hyperfractionation 1.2 Gy twice a day to the dose of 64.8 Gy was used [82,87]. Variable results of OS were observed (1-year OS 63-75%, 2-year OS 44-79%, 3-year OS 15-74%, 5-year OS 8-64%) [17,20,[74][75][76][77][78][79][80][82][83][84][85][86] (Table 2). With the use of hyperfractionation, the median local failure-free survival showed a trend in favor of hyperfractionated re-IMRT compared to standard fractionation (28.2 vs. 16.6 months, p = 0.164) but OS was not significantly different (34.8 vs. 35.5 months, p = 0.603) [87].…”

Management of locally recurrent nasopharyngeal carcinoma

“…Table 4 summarizes the published series reported since our last review [1,[69][70][71][72][73]. The number of patients treated with this technique is too small for robust comparisons with IMRT [69][70][71][72][73][74][75]. This is still considered a technical approach that remains under development.…”