International Journal of Radiation Oncology*Biology*Physics
CLINICAL INVESTIGATIONSalvage brachytherapy for patients with locally persistent nasopharyngeal carcinoma
Introduction
Persistent nasopharyngeal carcinomas (NPC) remain a challenge. Yan et al. showed that 36% (5/14) of the patients with histologically proven residual disease within 2 weeks of completion of external radiation therapy (ERT) would subsequently develop local recurrence if a booster dose was not given (1). Likewise, experience on the regression patterns of other head and neck tumors also showed that failure to achieve complete remission at or shortly after the completion of RT was associated with an increased risk of local failure 2, 3. Therefore, it is fair to speculate that a patient with locally persistent NPC carries an increased risk of developing local failure if a booster dose is not given.
Despite advances in imaging technology and treatment techniques, local failure still occurs in 20–37% of patients receiving adequate treatment to the nasopharynx in several contemporary series 4, 5, 6, 7. The treatment results of locally recurrent NPC are unsatisfactory, with a 5-year actuarial local control rate in the region of 15–36% 7, 8, 9. Patients with early-stage local recurrences, who are more amenable to nasopharyngectomy 7, 10, 11 or interstitial implants 6, 12, 13, tend to have a better chance of subsequent local control. This illustrates the importance of early detection of local failure. Given the poor outcome and high associated complications with retreatment, more aggressive primary treatment to secure high local control seems to be the approach with the least toxicity.
The present study is a retrospective analysis of a series of patients with locally persistent NPC treated by high-dose-rate (HDR) intracavitary brachytherapy with curative intent. Treatment results of the earlier patients have been reported elsewhere (14). In this series we update our earlier report by adding 48 cases. With a larger patient number and a longer follow-up period, the treatment results can provide some grounds for exploration of any possible therapeutic gain on dose escalation with brachytherapy.
Section snippets
Methods and materials
In the Department of Clinical Oncology at the Tuen Mun Hospital, 83 patients with locally persistent NPC, following a radical course of ERT, were treated with HDR intracavitary remote afterloading brachytherapy during the period March 1990 to February 1998. These 83 patients represented approximately 10% of our NPC patients treated during the same period. Another four patients with locally persistent disease were treated elsewhere with ERT and referred to our department for brachytherapy. Thus,
Results
The 5-year actuarial LFFS rates and DSS rates for the brachytherapy group and ERT alone group were 85% and 76.6% (p = 0.15) (Fig. 3), and 72% and 67.8% (p = 0.2), respectively. The corresponding 5-year actuarial LFFS rates for T1, T2, and T3 disease were 94.7%, 88.2%, 67.4%, and 84.1%, 79.8%, 62.6%. A trend of improvement in the local control of the brachytherapy group was seen, and the local control of T1 and T2 patients was in the region of 90%. In assessing local control, only the T staging
Discussion
One may criticize that not all the patients treated during the years 1990–1998 were included in the present analysis. Their inclusion could certainly add more valuable information. Nevertheless, we managed to include 383 consecutive nonmetastatic NPC patients treated during the years 1990–1993 as a control group for evaluating the role of brachytherapy. More detailed analysis of this control group was beyond the scope of the current discussion.
In the present study, patients with local
Conclusion
We have reasons to believe that locally persistent NPC carries an increased risk of local recurrence if adequate additional treatment is not given. In this study, we have shown an improvement in local control for early T-stage NPC patients after receiving salvage brachytherapy treatment.
Acknowledgements
The authors thank Prof. J. F. Fowler for his advice on the fractionation schedule and all the staff of the Department of Clinical Oncology for their contribution in the management of this series of patients.
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