IMRT with simultaneous integrated boost and concurrent chemotherapy for nasopharyngeal cancer: plan evaluation and treatment outcome.
OBJECTIVE
This study evaluated the outcome of intensity-modulated radiation therapy with simultaneous integrated boost and concurrent chemotherapy for nasopharyngeal cancer.


METHODS
We analyzed 53 consecutive nasopharyngeal cancer patients who received definitive treatment using intensity-modulated radiation therapy with simultaneous integrated boost and cisplatin-based concurrent chemotherapy. Forty-six patients were treated with concurrent chemoradiation and seven patients with induction chemotherapy plus concurrent chemoradiation. The gross tumor (PTV(70)) received 69.96 Gy (2.12 Gy/fraction), high-risk subclinical disease (PTV(60)) received 59.4 Gy (1.8 Gy/fraction) and low-risk subclinical disease (PTV(56)) received 56.1 Gy (1.7 Gy/fraction) in 33 fractions. Twenty-eight patients were treated with step-and-shoot intensity-modulated radiation therapy and 25 patients with helical tomotherapy. Dosimetric parameters were compared between the two modalities.


RESULTS
The median treatment duration was 49 days (range: 41-65 days). The complete response rate was 92.5%. Three local, two regional, one locoregional and seven distant failures were observed. With the median follow-up of 41 months (range: 8-89 months), the 3- and 5-year local control, locoregional control, disease-free survival and overall survival rates were 91.8 and 91.8%; 87.6 and 87.6%; 77.5 and 70.5%; and 86.4 and 82.1%, respectively. Grade 3 mucositis, dermatitis, leucopenia and grade 4 leucopenia were observed in 10, 1, 2 and 1 patient, respectively. No grade 3 or higher xerostomia occurred. Helical tomotherapy significantly improved dosimetric parameters including the maximum dose, volume receiving >107% of the prescribed dose and uniformity index (D(5)/D(95)).


CONCLUSIONS
Intensity-modulated radiation therapy with simultaneous integrated boost with concurrent chemotherapy is a safe and effective treatment modality for nasopharyngeal cancer. Helical tomotherapy has a dosimetric advantage over step-and-shoot intensity-modulated radiation therapy in a clinical setting.
Department of Radiation Oncology, Yonsei Cancer Center, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea.
Jun Won
JW
Kim
Jae Ho
JH
Cho
Ki Chang
KC
Keum
Joo Ho
JH
Kim
Gwi Eon
GE
Kim
Jong Young
JY
Lee
Soo Kon
SK
Kim
Chang Geol
CG
Lee
D000293:Adolescent; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage; D059248:Chemoradiotherapy / Q000009:adverse effects; D002945:Cisplatin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000628:therapy*; D011829:Radiation Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012449:Safety; D016019:Survival Analysis; D014018:Tissue Distribution
D000970:Antineoplastic Agents; D002945:Cisplatin