Comparison of treatment outcome and toxicity in patients with early stage nasal natural killer/T-cell lymphoma receiving conventional external beam radiation therapy versus intensity-modulated radiation therapy

Background and purpose: Radiotherapy is the main treatment strategy of early stage nasal natural killer(NK)/T-cell lymphoma.Recently,several studies have shown that intensity-modulated radiotherapy(IMRT) is superior to conventional radiotherapy in the treatment of head and neck cancer.The aim of the present study was to compare the therapeutic efficacy and acute and late adverse toxicities in patients with early stage nasal NK/T-cell lymphoma receiving conventional external beam radiation therapy(CRT) versus IMRT.Methods: Forty-six patients with localized stage ⅠE and ⅡE nasal NK/T-cell lymphoma treated in Lihuili Hospital between May 2005 and Nov.2011 were systemically reviewed.Of all the patients,32 patients received conventional radiotherapy(CRT group) and 14 received IMRT(IMRT group).Clinical treatment volume included bilateral nasal cavity,paranasal sinus and bilateral cervical region while cervical lymph node involved,two dimensional fields were applied to the patients in the CRT group with a total dose of 50-54 Gy in 25-27 fractions.Patients in IMRT group received 54 Gy in 27 fractions.Therapeutic efficacy and adverse effects were observed and compared between CRT and IMRT groups.Results: The CR rate of CRT and IMRT groups were 68.8% and 78.6%,respectively(P0.05),the 3-year-overall survival(OS) of IMRT group was 71.4 %,comparing 62.5 % of CRT group(P0.05).Statistical difference was not found in either CR rate or survival.The acute reactions like dry mouth,odynophagia,dysphagia,dermatitis and mucositis were observed in CRT and IMRT groups,less severe toxicities were notified in IMRT group with statistically significant difference(P0.05).Xerostomia and taste alteration were less in IMRT group than those in CRT group,whereas the severity of acoustic/optic impairments and late brain injury were not significantly different in both groups.Conclusion: Treatment outcomes in the IMRT and CRT groups were comparable,while fewer acute reactions and some of late toxicities were observed in the IMRT group,and potential improved quality of life can be achieved in patients with IMRT technique.