RT Journal Article
SR Electronic
T1 Hypofractionated Stereotactic Radiotherapy Using CyberKnife as a Boost Treatment for Head and Neck Cancer, a Multi-institutional Survey: Impact of Planning Target Volume
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 5755
OP 5759
VO 34
IS 10
A1 YAMAZAKI, HIDEYA
A1 OGITA, MIKIO
A1 HIMEI, KENGO
A1 NAKAMURA, SATOAKI
A1 YOSHIDA, KEN
A1 KOTSUMA, TADAYUKI
A1 YAMADA, YUJI
A1 FUJIWARA, MASATERU
A1 BAEK, SUNGJAE
A1 YOSHIOKA, YASUO
YR 2014
UL http://ar.iiarjournals.org/content/34/10/5755.abstract
AB Aim: To evaluate the role of hypofractionated stereotactic radiotherapy (hSRT) as a boost treatment for head and neck cancer. Patients and Methods: We conducted a multi-institutional retrospective review for the outcome of boost irradiation using CyberKnife for head and neck cancer patients from the charts of four Institutes. Twenty-five patients were treated with hSRT boost for primary site with a median follow-up of 28 months. Treatment sites were 11 nasopharynx, 7 oropharynx, one hypopharynx, 3 nasal cavity or paranasal sinus and three oral cancers. All patients underwent preceding conventional radiotherapy of 35 to 72 Gy (median, 50 Gy) in 1.2- to 2Gy-fractions. The dose and fractionation scheme of the Cyberknife SRT boost was individualized and the prescribed dose ranged from 12 Gy to 35 Gy in 1 to 5 fractions (median, 15 Gy in 3 fractions). Results: There were 18 complete responses, 6 partial responses and one progressive disease, resulting in 96% (24/25) response rate. Local control (LC) rates at 2- and 5-years were 89% and 71%, respectively. Progression-free survival (PFS) and overall survival (OS) at 2- and 5-years were 70%/ 83% and 70%/ 70%, respectively. Planning target volume (PTV) at boost treatment planning and initial response were predisposing factors for PFS and OS. Patients with PTV ≤20 cm3 showed better PFS (92%) and OS (100%) than those with a PTV > 20 cm3 (PFS, 61% and OS, 47%). Good initial response predicts better outcome in LC, PFS and OS. Conclusion: The results of the present study showed potential benefits of the CyberKnife hSRT boost. Smaller PTV and good initial response predict good outcome.