Retrospective analysis on treating nasopharyngeal carcinoma with accelerated fractionation (6 fractions per week) in comparison with conventional fractionation (5 fractions per week): report on 3-year tumor control and normal tissue toxicity.
OBJECTIVE
To assess the therapeutic gain achieved by accelerated fractionation for non-keratinizing/undifferentiated nasopharyngeal carcinoma (NPC).


METHODS
During January 1994 to October 1997, 325 patients were treated to a total dose of 66 Gy in 33-37 fractions: 167 (irradiated before mid-January 1996) with 5 daily fractions (CF) and subsequent 158 with 6 daily fractions (AF) per week. Their median treatment times were 46 and 39 days, respectively. Additional boost to parapharyngeal extension had been given to 181 and Cisplatin-based chemotherapy to 57 patients (24 concurrent with radiotherapy).


RESULTS
The AF group had significantly higher progression-free rate than the CF group (74 vs. 63% at 3 years, P=0.02 by the log-rank test). However, the difference in disease-specific survival (86 vs. 80%, P=0.39) and overall survival (81 vs. 78%, P=0.9) did not reach statistical significance. Strongly significant improvement in local failure-free rate was achieved for patients with T3-4 tumors (87 vs. 62%, P<0.01). Multivariate analyses showed that fractionation was an independent significant factor for overall progression: hazard ratio=0.63, 95% confidence interval: 0.41-0.98, P=0.04. Among the 268 patients treated with radiotherapy alone, those treated by AF had significantly higher incidence of acute reaction grade > or=3 (72 vs. 13%, P<0.01). However, all patients completed the scheduled dose without excessive prolongation, and no significant increase in late complications was observed (20 vs. 15% at 3 years, P=0.19).


CONCLUSIONS
The current analyses suggested that acceleration to 6 daily fractions per week could significantly improve the progression-free rate for NPC without excessive late toxicity. Improvement in local control was confined to T3-4 tumors.
Lee
A W
AW
Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, 3 Lok Man Road, Chai Wan, Hong Kong, PR China.
Sze
W M
WM
Yau
T K
TK
Yeung
R M
RM
Chappell
R
R
Fowler
J F
JF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002277:Carcinoma / Q000532:radiotherapy*; D017024:Chemotherapy, Adjuvant; D002945:Cisplatin / Q000627:therapeutic use; D016001:Confidence Intervals; D018450:Disease Progression; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D009333:Neck / Q000528:radiation effects; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D009367:Neoplasm Staging; D016017:Odds Ratio; D010614:Pharynx / Q000528:radiation effects; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015996:Survival Rate; D013997:Time Factors
D000970:Antineoplastic Agents; D002945:Cisplatin