Robotic system-based fractionated stereotactic radiotherapy in locally recurrent nasopharyngeal carcinoma.
OBJECTIVE
We reviewed survival, local control, and toxicity in patients with locally recurrent nasopharyngeal carcinoma (NPC) who had been treated with fractionated stereotactic radiotherapy (FSRT).


METHODS
Between June 2002 and March 2008, we retrospectively reviewed 35 patients with locally recurrent NPC treated using FSRT with CyberKnife. Gross tumor volumes ranged from 2.6 to 64.0 ml (median, 7.9 ml). Radiation doses were prescribed at the isodose line (75-84% of the maximum dose; median, 80%). The prescribed dose of FSRT ranged from 24 to 45 Gy (median, 33 Gy) in three or five fractions.


RESULTS
The overall survival (OS) rate, local failure-free survival (LFFS) rate, and disease progression-free survival (DPFS) rate at 5 years were 60%, 79%, and 74%, respectively. Twenty-three patients achieved complete response after FSRT. Only T stage at recurrence was an independent prognostic factor for OS and DPFS. Five patients exhibited severe late toxicity (Grade 4 or 5).


CONCLUSIONS
With regard to OS and LFFS, our study provided favorable outcomes. The incidence of severe late toxicities was acceptable in our study. FSRT would be considered as the alternative treatment of choice in re-irradiation for locally recurrent NPC.
Seo
YoungSeok
Y
Department of Radiation Oncology, Korea Institute of Radiological & Medical Sciences, Republic of Korea.
Yoo
HyungJun
H
Yoo
SungYul
S
Cho
ChulKoo
C
Yang
KwangMo
K
Kim
Mi-Sook
MS
Choi
ChulWon
C
Shin
YoungJu
Y
Lee
DongHan
D
Lee
GukHang
G
D002277:Carcinoma / Q000401:mortality / Q000601:surgery*; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000601:surgery*; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000601:surgery*; D011379:Prognosis; D016634:Radiosurgery / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012371:Robotics; D015996:Survival Rate