Adjuvant High-Dose Rate Brachytherapy After Chemoradiation for Treatment of Early T-Stage Nasopharyngeal Carcinoma

Ten-year outcomes of a randomised trial for locoregionally advanced nasopharyngeal carcinoma: A single-institution experience from an endemic area

OBJECTIVE

We previously reported the five-year results of a randomised trial that compared induction chemotherapy plus concurrent chemoradiotherapy (IC+CCRT) with induction chemotherapy plus radiotherapy (IC+RT) in patients with locoregionally advanced nasopharyngeal carcinoma (NPC). The aim of this study was to report the ten-year results and to explore potential prognostic factors.

METHODS

From August 2002 to April 2005, 408 patients with locoregionally advanced NPC were randomly assigned to receive either IC (carboplatin and floxuridine)+CCRT (carboplatin) or IC+RT. The survival rates were analysed using the Kaplan-Meier method and compared using the log-rank test. Multivariable analysis was performed to identify valuable prognostic factors.

RESULTS

The ten-year overall survival, failure-free survival, locoregional failure-free survival and distant failure-free survival rates for the entire patient cohort were 49.5%, 48.0%, 80.8% and 66.9%, respectively. No significant survival differences were found between the IC+CCRT and IC+RT arms. By 3 years from the date of randomisation, 62.5% of the relapses had been detected; no recurrence occurred after 8 years. Within 3 years after randomisation, 77.0% of the metastases were detected; 0.8% was identified after 8 years. Age, Union for International Cancer Control (UICC) N-stage, serum lactate dehydrogenase (LDH) and body mass index (BMI) were independent prognostic factors that predicted death. Smoking status and total radiotherapy dose were independent prognostic factors that predicted locoregional recurrence. UICC N-stage, LDH and BMI were independent prognostic factors that predicted distant metastasis.

CONCLUSIONS

Concurrent carboplatin chemotherapy did not significantly improve the long-term survival after inductive carboplatin and floxuridine chemotherapy in locoregionally advanced nasopharyngeal carcinoma. In addition to patient and tumour characteristics, LDH, BMI and smoking status were important baseline prognostic factors for tumour recurrence or distant metastasis; these are worthy of further prognostic investigation in future studies.

Dose Escalation of Three-dimensional Conformal Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma: A Prospective Randomised Study

AIMS

To investigate prospectively the feasibility and efficacy of dose escalation using three-dimensional conformal radiotherapy (3D-CRT) boost technique for locally recurrent nasopharyngeal carcinoma (NPC) in a randomised study.

MATERIALS AND METHODS

Thirty-six patients with locally recurrent NPC (>6 months interval from previous radical radiotherapy, no cervical lymph-node involvement and no distant metastasis) were enrolled. Treatment included conventional external-beam radiotherapy to 54 Gy, followed by a 3D-CRT boost to the gross tumour region. Patients were randomised to three boost dose levels: 16 Gy, 20 Gy and 24 Gy for groups I, II and III, respectively, with 12 patients in each group. All boost doses were delivered in 4-Gy fractions and 3 fractions per week. Median follow-up was 27 months (range 14-44 months).

RESULTS

Three-year, local-recurrence-free survival rate was significantly higher (72%) for the high-dose group III than for groups I and II (37% and 28%, respectively, P = 0.047). No significant difference was found in the 3-year overall survival rate among the three groups (72%, 59% and 82% for groups I, II and III, respectively). Three-year distant metastases rates were 17%, 0% and 18%, respectively. Skull-base invasion (P = 0.017) and pathology (P = 0.0006) correlated with overall survival. Treatment was well tolerated and no significant difference was observed among the three groups in acute and late toxicities (grade III toxicity is minimal: 17%, 17%, 0% of oral mucositis and 25%, 17%, 17% of nasopharyngeal mucositis in groups I, II, III, respectively, and 8% leukocytopenia only in group II; no grade IV toxicity occurred in any of the groups except for a fatal bleeding in group III).

CONCLUSIONS

Re-irradiation with high-dose 3D-CRT boost technique results in high local control rate and acceptable toxicity in patients with recurrent NPC. Dose escalation to the boost volume to 78 Gy (54 Gy + 24 Gy boost) results in improved recurrence-free survival compared with lower doses.