Open AccessEarly clinical outcomes of helical tomotherapy/intensity‐modulated proton therapy combination in nasopharynx cancer
Author(s) -
Park Seung Gyu,
Ahn Yong Chan,
Oh Dongryul,
Noh Jae Myoung,
Ju Sang Gyu,
Kwon Dongyeol,
Jo Kwanghyun,
Chung Kwangzoo,
Chung Eunah,
Lee Woojin,
Park Seyjoon
Publication year - 2019
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/cas.14115
Subject(s) - tomotherapy , medicine , mucositis , proton therapy , radiation therapy , propensity score matching , nuclear medicine , univariate analysis , cancer , head and neck cancer , multivariate analysis
This study aimed to evaluate the feasibility of combining helical tomotherapy ( HT ) and intensity‐modulated proton therapy ( IMPT ) in treating patients with nasopharynx cancer ( NPC ). From January 2016 to March 2018, 98 patients received definitive radiation therapy ( RT ) with concurrent chemotherapy ( CCRT ). Using simultaneous integrated boost and adaptive re‐plan, 3 different dose levels were prescribed: 68.4 Gy in 30 parts to gross tumor volume (GTV) , 60 Gy in 30 parts to high‐risk clinical target volume (CTV) , and 36 Gy in 18 parts to low‐risk CTV . In all patients, the initial 18 fractions were delivered by HT , and, after rival plan evaluation on the adaptive re‐plan, the later 12 fractions were delivered either by HT in 63 patients (64.3%, HT only) or IMPT in 35 patients (35.7%, HT / IMPT combination), respectively. Propensity‐score matching was conducted to control differences in patient characteristics. In all patients, grade ≥ 2 mucositis (69.8% vs 45.7%, P = .019) and grade ≥ 2 analgesic usage (54% vs 37.1%, P = .110) were found to be less frequent in HT / IMPT group. In matched patients, grade ≥ 2 mucositis were still less frequent numerically in HT / IMPT group (62.9% vs 45.7%, P = .150). In univariate analysis, stage IV disease and larger GTV volume were associated with increased grade ≥ 2 mucositis. There was no significant factor in multivariate analysis. With the median 14 month follow‐up, locoregional and distant failures occurred in 9 (9.2%) and 12 (12.2%) patients without difference by RT modality. In conclusion, comparable early oncologic outcomes with more favorable acute toxicity profiles were achievable by HT / IMPT combination in treating NPC patients.