Hyperfractionated radiotherapy followed by adjuvant chemotherapy for nasopharyngeal cancer: report of seven cases.

Cases of hyperfractionated radiotherapy and adjuvant chemotherapy for nasopharyngeal cancer are reported. Seven patients received hyperfractionated radiotherapy (76.8-81.6 Gy/64-68 fractions to primary tumor) and two cycles of cisplatin (80 mg/m2 i.v. on day 1) plus 5-FU (800 mg/m2 continuous infusion on days 2-6). Mucositis was the most frequent side effect in hyperfractionated radiotherapy. Moderate leukopenia was the major side effect of adjuvant chemotherapy. With a mean follow-up time of 34 months (range 25-48 months), five of the seven patients were locoregionally controlled. Two developed distant metastases. Two patients suffered late complications (posterior nasopharyngeal wall necrosis and brain necrosis). These results suggested that our regimen was almost well tolerated and might be of use in locoregional control of nasopharyngeal cancer. However, it carries some risk of late complications and might be inadequate for preventing distant metastases. A three-dimensional conformal boost irradiation technique and adequate dose intensity chemotherapy might be encouraged.

[Comparison of calculated and measured rectal doses in HDR brachytherapy with Ir-192 source].

Two orthogonal radiographs are used to reconstruct the three-dimensional positions of applicators (sources) and their dosemeter for assessing afterloading techniques. It has always been assumed that the applicators are perfectly fixed and unchanged during irradiation. In a review comparing measurements by a five-detector dosemeter and calculated doses in our institution, a relatively poor correlation (correlation coefficient = 0.79) was observed. The purpose of this study was to investigate the sources of this difference between calculated and measured rectal doses in HDR brachytherapy with Ir-192 source. In this study, the calculated dose was used as a reference value. The overall percentage difference between calculated and measured rectal doses was estimated at 9%. The major source of the difference between calculated and measured rectal doses was applicators and dosemeter movement during irradiation. This was verified by X-ray fluoroscopy during irradiation. It was found that loose fastening of the applicators caused a change in the position of the applicators and dosemeter during irradiation. By improving the fastening of the applicators and dosemeter, the correlation (correlation coefficient = 0.90) between calculated and measured doses was improved. The results demonstrate the importance of the fastening of the applicators and dosemeter.