[Long-term efficacy of external radiotherapy plus intracavitary hyperfractionated brachytherapy on nasopharyngeal carcinoma].
OBJECTIVE
Intracavitary hyperfractionated brachytherapy is one of the main methods in brachytherapy for early stage nasopharyngeal carcinoma (NPC). We developed the parapharyngeal space interstitial brachytherapy for the NPC patients with residual tumor in the parapharyngeal space after external radiotherapy, and used hyperfractionated brachytherapy as a boosting radiation for the locally advanced patients who have no tumor invasion in the base of skull. This study was to analyze the long-term efficacy of external radiotherapy plus intracavitary hyperfractionated brachytherapy on NPC, and explore the clinical value and suitable dose.


METHODS
From Jan. 1998 to Dec. 2002, 352 NPC patients were treated by external radiotherapy plus intracavitary hyperfractionated brachytherapy in Fujian Provincial Tumor Hospital. The parapharyngeal space interstitial brachytherapy was used in the patients with residual tumor in the parapharyngeal space after external radiotherapy. The external irradiation dose varied from 50 to 70 Gy. Brachytherapy was delivered by 2.5-3.0 Gy per fraction, and 2 fractions per day with an interval of 6 h; the total dose ranged from 5 to 32 Gy with a median of 17 Gy.


RESULTS
The overall 1-, 2-, 3-, and 5-year disease-free survival rates were 97.0%, 91.3%, 87.6%, and 84.7%, respectively. The 5-year survival rate was significantly higher in stage I-II patients than in stage III-IV patients (88.2% vs. 79.2%, P=0.016)û but the local control rate was similar in the 2 groups (94.1% vs. 91.7%). Thirty-two (9.4%) patients had radiation injury at the lower cranial nerve.


CONCLUSIONS
External radiotherapy plus intracavitary and interstitial hyperfractionated brachytherapy can improve local control rate and survival rate of NPC, but the occurrence rate of radiation injury at the lower cranial nerve is higher in the patients with parapharyngeal space involvement than in other patients.
Lin
Shao-Jun
SJ
Department of Radiation Oncology, Fujian Provincial Tumor Hospital, Fujian Medical University, Fuzhou, Fujian, PR China.
Pan
Jian-Ji
JJ
Wu
Jun-Xin
JX
Han
Lu
L
Pan
Cai-Zhu
CZ
D000293:Adolescent; D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D003037:Cobalt Radioisotopes; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D010315:Particle Accelerators; D011832:Radiation Injuries / Q000209:etiology; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000009:adverse effects; D015996:Survival Rate; D014987:Xerostomia / Q000209:etiology; D055815:Young Adult
D003037:Cobalt Radioisotopes