[A new applicator with regulatable air bag designed for intracavitary brachytherapy of nasopharyngeal carcinoma].
OBJECTIVE
Nasopharynx applicator used in intracavitary brachytherapy plays an important role in the radiotherapy of nasopharyngeal carcinoma (NPC), its quality affects the efficiency of treatment. This study was to design a new applicator for clinical use.


METHODS
An inexpensive, reusable, and flexible latex nasopharynx applicator was designed. An air bag was placed at 15 mm from the foreside of the applicator, clung to the tube. The edge of air bag is tangent to the axis of tube. When the bag was full of air, the tube would hunch reversely,close to nasopharyngeal vault. After introduced into nasopharynx through middle nasal meatus, the applicator could be fixed in suitable position by its rotation, and air bag regulation, and confirmed its position by simulation.


RESULTS
A total of 221 patients with NPC were treated with external beam radiation therapy in our hospital, and boosted HDR brachytherapy using this new applicator. The response rate was 92.6% in the primary tumor group (200/216), and 100% in the recurrent tumor group (5/5). Mucosal necrosis in the posterior or anterior wall of nasopharynx occurred in 5 patients, 8 patients experienced nasal congestion and nasal synechia.


CONCLUSIONS
This new nasopharynx applicator is easy to operate, painless, and well dosage-distributed. Mucosal necrosis is likely due to higher fractional dose.
Zhang
Ning
N
Department of Radiation Oncology, The First People's Hospital of Foshan City, Foshan, Guangdong, 528041, P.R.China. z7751@21cn.com
Wei
Guang-Yu
GY
Tan
Yi-Chang
YC
Huang
Ze-Li
ZL
Li
Shao-En
SE
Lu
Zhi-Qian
ZQ
D000293:Adolescent; D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000295:instrumentation* / Q000379:methods; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D003037:Cobalt Radioisotopes / Q000627:therapeutic use; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D016896:Treatment Outcome
D003037:Cobalt Radioisotopes