Data Interpretation, Statistical ; Humans ; Orthopedics ; Research Design ; Software

[Abstra ct] Objective To investigate the long-term efficacy and adverse effects of intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).Methods A total of 869 patients with biopsy-proven NPC without distant metastasis who underwent the whole course of IMRT from 2009 to 2010 were enrolled.Of all the patients, 84.8%received cisplatin-based chemotherapy.The prescribed dose to the primary lesion in the nasopharynx was 66-70Gy in 30-32 fractions, and the dose to the positive lymph nodes in the neck was 66 Gy in 30-32 fractions.The Kaplan-Meier method was used to calculate survival rates, the log-rank test was used for difference analysis and univariate prognostic analysis , and the Cox proportional hazards model was used for multivariate prognostic analysis .Rseu lts The 5-year overall survival( OS ) , local recurrence-free survival, regional recurrence-free survival, distant metastasis-free survival, and disease-free survival ( DFS ) were 84.0%, 89.7%, 94.5%, 85.6%, and 76.3%, respectively.In the patients with locally advanced NPC,concurrent chemotherapy tended to reduce distant metastasis (83.6%vs.75.7%, P=0.050) and improve OS (82.6%vs.77.0 %, P=0.082).Induction chemotherapy tended to improve OS ( 80.7% vs.71.4%, P=0.057 ) , and the induction chemotherapy containing docetaxel or gemcitabine tended to improve OS (83.3%vs.72.2%, P=0.058).The patients who received a boost after the initial radiotherapy had a significantly lower DFS rate than those who did not (52.2%vs.71.1%, P=0.004).The concurrent chemotherapy increased the incidence rates of long-term xerostomia and trismus, while a high dose of cisplatin increased the incidence rates of xerostomia and hearing impairment.Conclusions IMRT for NPC provides satisfactory long-term efficacy.Concurrent chemotherapy combined with IMRT tends to reduce the incidence of distant metastasis, and other values need further investigation.The boost therapy after radiotherapy may be associated with poor prognosis.Chemotherapy increases the incidence of long-term toxicities.

Objective To compare the image quality of three high-resolution dynamic MRI methods for evaluating the motion of temporomandibular joint disc and condyle. Methods Twenty-five patients with suspected temporomandibular joint disorders were examined by single-shot fast spin-echo (SSFSE),fast imaging employing steady-state acquisition (FIESTA),and spoiled gradient echo (SPGR) on the oblique sagittal position.Two radiologists performed subjective and objective evaluation on the images with double-blind method.The subjective evaluation included the signal intensity of mandibular condyle,articular disc,soft tissue around articular disc,and lateral pterygoid muscle,the contrast between articular disc and condyle,the contrast between articular disc and surrounding soft tissue,condylar motion,and disc movement.The objective evaluation indexes included image signal intensity,signal-to-noise ratio (SNR),and contrast-to-noise ratio (CNR).The subjective and objective indexes of the image quality were compared between the three sequences. Results The SSFSE sequence had lower signal intensity of articular disc and higher signal intensity of condyle and surrounding soft tissue than FIESTA and SPGR sequences (all P<0.001).The SPGR sequence showed higher signal intensity of lateral pterygoid muscle than the SSFSE and FIESTA sequences (P=0.017,P<0.001).Among the three sequences,SSFSE sequence showed the clearest articular disc structure (χ²=41.952,P<0.001),the strongest contrast between articular disc and condyle (χ²=35.379,P<0.001),the strongest contrast between articular disc and surrounding soft tissue (χ²=27.324,P<0.001),and the clearest movement of articular disc (χ²=44.655,P<0.001).SSFSE and FIESTA sequences showed higher proportion of disc displacement and reduction than SPGR sequence (all P<0.001).The CNR (χ²=21.400,P<0.001),SNR (χ²=34.880,P<0.001),and condyle signal intensity (F=337.151,P<0.001) demonstrated differences among SSFSE,FIESTA,and SPGR sequences.The CNR of SSFSE sequence was higher than that of FIESTA sequence (P<0.001),while it had no significant difference between SSFSE and SPGR sequences (P=0.472).In addition,the SSFSE sequence had higher SNR and signal intensity than FIESTA and SPGR sequences (all P<0.001). Conclusion The best image quality can be observed from SSFSE sequence where both the structure and movement of temporomandibular joint are well displayed.Therefore,SSFSE is preferred for the examination of temporomandibular joint movement.
Humans ; Temporomandibular Joint/diagnostic imaging* ; Motion ; Plastic Surgery Procedures