[Effect of intensity modulated radiation therapy on oral mucosa and immune function in patients with nasopharyngeal carcinoma].

OBJECTIVE: To study the potential effects of intensity modulated radiation therapy (IMRT) on clinical efficacy, oral mucosa reaction and immunological foundation; and to explore the effect of immunological changes on clinical efficacy and oral mucosa reaction in patients with nasopharyngeal carcinoma.
 Methods: A total of 200 patients with nasopharyngeal carcinoma, who came from First Department of Nasopharyngeal Radiotherapy, the First People's Hospital of Foshan from October 2008 to November 2011, were selected. The patients were treated with nasopharyngeal radiotherapy, and divided into an observation group and a control group (n=100 in each group). The control group underwent common conventional two-dimensional radiotherapy treatment, while the observation group underwent IMRT. The 5-year survival rates and recurrence rates were recorded at follow-up. After the radiotherapy, the oral mucosa in the patients were evaluated by the classification standard of acute radioactive mucositis by American Radiotherapy Oncology Group (RTOG), and the number of T lymphocyte subsets before and after treatment was detected.
 Results: There were significant difference in non-regional-recurrence survival rate, disease-free survival rate, local recurrence rate between the above 2 groups (all P<0.05), but no significant difference in the distant metastasis-free survival rate (P>0.05). The acute oral mucosa reactions of grade 1, 2, 3, 4 in the control group were 8.00%, 20.00%, 12.00%, 7.00%, respectively, and those were 7.00%, 22.00%, 15.00%, 1.00% respectively. There was no significant difference in the acute response of oral mucosa in grade 1, 2 and 3 in the 2 groups (all P>0.05), but there was significant difference in the grade 4 (P<0.05). There were significantly difference in CD8+, CD4+/ CD8+ and CD4+ T lymphocyte subsets before and after treatment in the above 2 groups (all P<0.01); there were also significantly difference after treatment between the observation group and the control group (all P<0.01).
 Conclusion: In the process of treatment in patients with nasopharyngeal carcinoma, the use of IMRT on the basis of chemotherapy is more effective than the conventional two-dimensional radiotherapy, which can reduce the proportion of grade 4 (severe) acute oral mucosa reaction. It may be related to the protective effect of IMRT on immune function in the patients.

Prognostic significance of maximum primary tumor diameter in nasopharyngeal carcinoma.

BACKGROUND: To evaluate the prognostic value of maximum primary tumor diameter (MPTD) in nasopharyngeal carcinoma (NPC). METHODS: Three hundred and thirty-three consecutive, newly-diagnosed NPC patients were retrospectively reviewed. Kaplan-Meier analysis and the log-rank test were used to estimate overall survival (OS), failure-free survival (FFS), distant metastasis-free survival (DMFS) and local relapse-free survival (LRFS). Cox proportional hazards regression analysis was used to assess the prognostic value of MPTD. RESULTS: Median follow-up was 66 months (range, 2-82 months). Median MPTD in stage T1, T2, T3 and T4 was 27.9, 37.5, 45.0 and 61.3 mm, respectively. The proportion of T1 patients with a MPTD ≤ 30 mm was 62.3%; 72% and 62.9% of T2 and T3 patients had a MPTD > 30-50 mm, and 83.5% of T4 patients had a MPTD > 50 mm. For patients with a MPTD ≤ 30 mm, > 30-50 mm and > 50 mm, the 5-year OS, FFS, DMFS and LRFS rates were 85.2%, 74.2% and 56.3% (P < 0.001); 87%, 80.7% and 62.8% (P < 0.001); 88.7%, 86.4% and 72.5% (P = 0.003); and 98.2%, 93.2% and 86.3% (P = 0.012), respectively. In multivariate analysis, MPTD was a prognostic factor for OS, FFS and DMFS, and the only independent prognostic factor for LRFS. For T3-T4 patients with a MPTD ≤ 50 mm and > 50 mm, the 5-year OS, FFS and DMFS rates were 70.4% vs. 58.4% (P = 0.010), 77.5% vs. 65.2% (P = 0.013) and 83.6% vs. 73.6% (P = 0.047), respectively. In patients with a MPTD ≤ 30 mm, 5-year LRFS in T1, T2, T3 and T4 was 100%, 100%, 88.9% and 100% (P = 0.172). CONCLUSIONS: Our data suggest that MPTD is an independent prognostic factor in NPC, and incorporation of MPTD might lead to a further refinement of T staging.

[A new applicator with regulatable air bag designed for intracavitary brachytherapy of nasopharyngeal carcinoma].

BACKGROUND & 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.