International Journal of Hematology and Oncology 2019, Vol 29, Num 3 Page(s): 023-030
Stereotactic Reirradiation of Recurrent Nasopharyngeal Carcinoma Using CyberKnife System: Preliminary Results

M. Faik CETINDAG1, Aysen DIZMAN1, Zafer OZDOGAN1, Suheyla A. ARSLAN1, Yıldız GUNEY1, Bilgin K. ARIBAS2, Kemal ARDA2, Gulin U. VURAL3, Dincer YEGEN4

1Dr. A.Y. Oncology Training and Research Hospital, Department of Radiation Oncology, Ankara, TURKEY
2Dr. A.Y. Oncology Training and Research Hospital, Department of Radiology, Ankara, TURKEY
3Dr. A.Y. Oncology Training and Research Hospital, Department of Nuclear Medicine, Ankara, TURKEY
4Dr. A.Y. Oncology Training and Research Hospital,Department of Radiation Oncology, Ankara, TURKEY

Keywords: Stereotactic radiotherapy, Recurrent nasopharyngeal carcinomas, CyberKnife
Local recurrence of nasopharyngeal carcinoma (NPC) represents a major cause of mortality and morbidity with or without systemic illness. Fractionated Stereotactic radiotherapy (FSRT) is an option for salvage treatment. This study reviewed the treatment outcomes of recurrent NPC in terms of efficacy and toxicity.

Between February 2009 and December 2009, 12 patients (8 men and 4 women), median age at diagnosis was 49, (range 18-69) with biopsy proven (10 of 12 patients) locally recurrent NPC were treated using FSRT with CyberKnife (Accuray Inc. Sunnyvale, CA). Median prescribed dose was 25 Gy (range 24-30) delivered to median 75% isodose line (range 70%-80%) in 5 to 6 fractions. GTVs were delineated using PET-CT images in 5 patients and MRI in 7 patients (median GTV 29.4 ml, range 4.9-78.7). Median follow-up was 11.5 months (range 6-18). Between February 2009 and December 2009, 12 patients (8 men and 4 women), median age at diagnosis was 49, (range 18-69) with biopsy proven (10 of 12 patients) locally recurrent NPC were treated using FSRT with CyberKnife (Accuray Inc. Sunnyvale, CA). Median prescribed dose was 25 Gy (range 24-30) delivered to median 75% isodose line (range 70%-80%) in 5 to 6 fractions. GTVs were delineated using PET-CT images in 5 patients and MRI in 7 patients (median GTV 29.4 ml, range 4.9-78.7). Median follow-up was 11.5 months (range 6-18).

Complete response rate after FSRT was 66.7% (8 patients), partial response rate was 33.3% (4 patients). One-year local failure- free survival (LFFS) and overall survival rates were 85% and 75% respectively (2 patients with complete response after FSRT developed local relapse, 4 patients died; the reason for death was disease progression in other sites in 3 patients and treatment related complication in 1 patient). Treatment related grade 3 or more toxicity was observed in 5 patients (33% early and 9% late, total 42.3%).

Our preliminary results provided acceptable outcomes with FSRT as a salvage treatment of NPC with regard to early response rate and toxicity.