Volumetric parameters derived from FLT-PET performed at completion of treatment predict efficacy of Carbon-ion Radiotherapy in patients with locally recurrent Nasopharyngeal Carcinoma

Abstract

The purpose of this study was to investigate the role of 3'-deoxy-3'-[ 18 F]fluorothymidine (FLT)-PET for predicting the outcome of patients with locally recurrent nasopharyngeal carcinoma (LR-NPC) treated by carbon-ion radiotherapy (CIRT). Patients received FLT-PET/CT scan one-week prior to or after completion of CIRT were enrolled in the study. All patients were from prospective trials or treated using a standardized protocol. Time-dependent receiver operator characteristics (ROC) were used to determine the optimal cutoff values for FLT-PET parameters. Univariable and multivariable analyses of local progression-free survival (LPFS) were performed using Cox regression, to examine the prognostic value of FLT-PET parameters, including SUV max , metabolic tumor volume (MTV) and total lesion thymidine (TLT). A total of 41 patients were enrolled. Elevated MTV and TLT were significantly associated with worse LPFS, in both univariable and multivariable analyses. ROC analysis revealed that both an MTV value higher than 8.6 and a TLT value higher than 14.9 were predictive of increased risk of developing local recurrence, the adjusted HRs were 5.59 ( p =0.009) and 7.76 ( p =0.002), respectively. In conclusion, FLT-PET was found to be a promising prognostic tool for LR-NPC patients and might play a role in the treatment guidance.

Particle beam therapy for nasopharyngeal cancer: A systematic review and meta-analysis

“…All the included studies were published from 2015 to 2021, with majority of them being published between 2019 and 2021 (n = 22). Among these included studies, nine were conducted in the United States [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] and 6 in China [20] , [21] , [22] , [23] , [24] , [25] . The remaining studies were conducted in Germany (n = 2) [26] , [27] , Italy (n = 2) [28] , [29] , Japan (n = 2) [30] , [31] , South Korea (n = 2) [32] , [33] , Taiwan (n = 1) [34] , Czech Republic (n = 1) [35] and Hong Kong (n = 1) [36] .…”

“…Seven papers had a patient size of 50 or more [13] , [20] , [21] , [22] , [26] , [32] , [34] , and only one of them had a sample size of more than 100 [21] ( Table 1 ). By definition of NPC in this systematic review, seventeen studies included patients with primary [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [22] , [26] , [27] , [28] , [31] , [33] , [34] , [35] and 8 included recurrent NPC [20] , [21] , [23] , [24] , [25] , [29] , [32] , [36] . The remaining study included both [30] .…”

“…Among the 26 included studies, nineteen reported prespecified survival outcomes, including OS (n = 16) [11,13,16,17,[19][20][21][22][23]26,27,29,30,32,34,35], PFS (n = 9) [16,19,20,22,24,28,30,33,34], LC (n = 10) [13,16,21,22,[26][27][28][29][30]35], and regional control (n = 3) [13,21,22]. Eighteen studies reported toxicity [11][12][13]16,17,[19][20][21][22][26][27][28][29]…”

“…Safety outcomes: a. Toxicity Hu, J. et al (2020b; China) [23] 41 N/A N/A WHO: I/II: 13 III/IVa/IVb: 28 29–70 (46) Recurrent NPC 3–43 (15) 2.5–3 GyE (3 GyE) N/A 50–64 GyE (60 GyE) CIBT N/A 1. Survival outcomes:a. OS (1 year) b.…”

“…The 26 studies included a total of 1502 NPC patients, with sample sizes varying from 10 to 358. Seven papers had a patient size of 50 or more [13,[20][21][22]26,32,34], and only one of them had a sample size of [20,21,[23][24][25]29,32,36]. The remaining study included both [30].…”