Comparison of long-term survival and toxicity of simultaneous integrated boost vs conventional fractionation with intensity-modulated radiotherapy for the treatment of nasopharyngeal carcinoma.
OBJECTIVE
In recent years, the intensity-modulated radiotherapy with simultaneous integrated boost (IMRT-SIB) and intensity-modulated radiotherapy with conventional fractionation (IMRT-CF) have been involved in the treatment of nasopharyngeal carcinoma (NPC). However, the potential clinical effects and toxicities are still controversial.


METHODS
Here, 107 patients with biopsy-proven locally advanced NPC between March 2004 and January 2011 were enrolled in the retrospective study. Among them, 54 patients received IMRT-SIB, and 53 patients received IMRT-CF. Subsequently, overall survival (OS), 5-year progression-free survival (PFS), 5-year locoregional recurrence-free survival (LRFS), and relevant toxicities were analyzed.


RESULTS
In the present study, all patients completed the treatment, and the overall median follow-up time was 80 months (range: 8-126 months). The 5-year OS analysis revealed no significant difference between the IMRT-SIB and IMRT-CF groups (80.9% vs 80.5%, P=0.568). In addition, there were also no significant between-group differences in 5-year PFS (73.3% vs 74.4%, P=0.773) and 5-year LRFS (88.1% vs 90.8%, P=0.903). Notably, the dose to critical organs (spinal cord, brainstem, and parotid gland) in patients treated by IMRT-CF was significantly lower than that in patients treated by IMRT-SIB (all P<0.05).


CONCLUSIONS
Both IMRT-SIB and IMRT-CF techniques are effective in treating locally advanced NPC, with similar OS, PFS, and LRFS. However, IMRT-CF has more advantages than IMRT-SIB in protecting spinal cord, brainstem, and parotid gland from acute and late toxicities, such as xerostomia. Further prospective study is warranted to confirm our findings.
Department of 6th Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan University-Shandong Academy of Medical Sciences, Jinan, People's Republic of China; School of Medicine and Life Sciences, Jinan University-Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
Hengmin
H
Tao
Department of 6th Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan University-Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
Yumei
Y
Wei
Department of 6th Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan University-Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
Wei
W
Huang
Department of 6th Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan University-Shandong Academy of Medical Sciences, Jinan, People's Republic of China; School of Medicine and Life Sciences, Jinan University-Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
Xiujuan
X
Gai
Department of 6th Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan University-Shandong Academy of Medical Sciences, Jinan, People's Republic of China.
Baosheng
B
Li
intensity-modulated radiotherapy with conventional fractionation; intensity-modulated radiotherapy with simultaneous integrated boost; nasopharyngeal carcinoma; survival; toxicities