Korean Journal of Head & Neck Oncology 2003;19(1):9-15.
Published online May 30, 2003.

"Simultaneous Modulated Accelerated Radiation Therapy" (SMART) Intensity-Modulated Radiotherapy in the Treatment of Nasopharyngeal Carcinoma : the Asan Medical Center

Sang wook Lee;Geum Mun Back;Byong Yong Yi;Eun Kyung Choi;Jong Hoon Kim;Seung Do Ahn;Seong Soo Shin;Sang Yoon Kim;Soon Yuhl Nam;Seung Ho Choi;Sung Bae Kim;Si yeol Song

비인강암의 세기조절방사선치료기술을 이용한 동시차등조사가속치료의 예비성적

이상욱;백금문;이병용;최은경;김종훈;안승도;신성수;김상윤;남순열;최승호;김성배;송시열

Abstract

Purpose
To introduce our early experience with intensity-modulated radiotherapy (IMRT) in the treatment of nasopharyngeal carcinoma.
Methods
and Materials: Eight patients who underwent IMRT for no disseminated nasopharyngeal carcinoma at the Asan Medical Center between September 2001 and November 2002 were evaluate by prospective analysis. According to the 1997 American Joint Committee on Cancer staging classification, 5 had Stage III, and 3 had Stage IVB disease. The IMRT plans were designed to be delivered as a 'Simultaneous Modulated Accelerated Radiation Therapy' (SMART) using the 'step and shoot' technique with a MLC (multileaf collimator). Daily fractions of 2.2-2.5Gy and 1.9-2Gy were prescribed and delivered to the GTV and CTV and clinically negative neck node, respectively. The prescribed dose was 70A-79.0Gy to the gross tumor volume (GTV), 60Gy to the clinical target volume (CTV) and metastatic nodal station, and 46Gy to the clinically negative neck. All patients also received weekly cisplatin during radiotherapy. Acute and late normal tissue effects were graded according to the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria.
Results
Follow-up period was ranging from 5 to 18 months. All patients showed complete response and loco-regional control rate was 100% but one patient died of malnutrition due to treatment related toxicity. There were no Grade 3 or 4 xerostomia and all patients had experienced improvement of salivary gland function.
Conclusion
'Simultaneous Modulated Accelerated Radiation Therapy' (SMART) boost intensity-modulated radiotherapy technique allows parotid sparing as evidenced both clinically and by dosimetry. Initial tumor response and loco-regional control was promising. It is clinically feasible. A larger population of patients and a long-term follow-up are needed to evaluate ultimate tumor control and late toxicity.

Key Words: Nasopharyngeal carcinoma, IMRT, CCRT