BACKGROUND:Adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) is an extremely rare head and neck malignancy. The study aimed to investigate the long-term outcomes and late toxicity of postoperative radiotherapy (PORT) for patients with EAC ACC. METHODS:Between 2004 and 2021, 60 patients with EAC ACC were retrospectively analyzed. The overall survival (OS), local recurrence-free survival (LRFS), nodal recurrence-free survival (NRFS), and distant metastasis-free survival (DMFS) were calculated by the Kaplan-Meier method. RESULTS:With a median follow-up of 110.3 months, the 10-year OS, LRFS, NRFS, and DMFS rates were 84.2%, 79.5%, 96.2%, and 59.9% after PORT, respectively. Eleven patients (18.3%) experienced local failure, 2 (3.3%) had regional failure, and 23 (38.3%) had distant metastasis (DM). Multivariate analysis showed that the advanced T stage (T3-4) was an independent risk factor for OS (p = 0.019) and DMFS (p = 0.006). Late toxicities were assessed in 45 patients. Among them, 73.3% (33/45) of patients experienced grade 3-4 ipsilateral hearing loss after surgery. Furthermore, xerostomia (31.1%, 14/45) and radiation-related caries (26.7%, 12/45) were the most common late toxicities of radiotherapy-related. For clinical N0 (cN0) patients (n = 58), the ipsilateral elective neck irradiation (ENI) did not improve the OS (p = 0.929), NRFS (p = 0.317), or DMFS (p = 0.778) for the advanced patients (T3-4). CONCLUSIONS:Surgery plus PORT is associated with excellent long-term survival with tolerable late toxicity for EAC ACC patients. ENI of cN0 patients shows no survival benefit, which suggests that the omission of ENI is reasonable to reduce radiation-related toxicity.

Background/Objectives: Pediatric obstructive sleep apnea (OSA), particularly when accompanied by mandibular retrognathia, presents as a complex, multifactorial condition. Dentofacial orthopedic treatment (DOT) has gained increasing clinical attention; however, high-level evidence specifically demonstrating its efficacy in pediatric OSA remains scarce. This study aimed to evaluate the efficacy of DOT and AT in managing mild to moderate OSA in children with mandibular retrognathia. Methods: This open-label, randomized controlled clinical trial recruited 93 children aged 7-10 years with mild to moderate OSA (an AHI of 1-10 events per hour) and mandibular retrognathia (ANB angle ≥ 4.5°). Participants were randomly allocated to four groups: pharmacotherapy, DOT (combined maxillary expansion and mandibular advancement appliance), AT (adenotonsillectomy under general anesthesia), and AT & DOT groups. The primary outcome was the change in apnea-hypopnea index (AHI) from baseline to 7 months post-treatment. Secondary outcomes included assessments of dentofacial development and volumetric changes in the upper airway. Results: Because of the high dropout/loss-to-follow-up rates in the pharmacotherapy and AT plus DOT groups, the final analysis was restricted to the DOT and AT groups, in which the overall dropout/loss-to-follow-up rate was 19.6%. Among the 43 participants allocated to the DOT (8 girls and 15 boys) and AT groups (8 girls and 12 boys), 36 completed the follow-up, the median baseline AHI was 3.7 events/h [IQR, 1.9-4.4]. Per protocol analysis revealed a mean reduction in AHI of 1.6 events/h in the DOT group and 1.3 events/h in the AT group, with no significant difference between the groups (-0.43 [95% CI, -1.48 to 0.61], p = 0.40). DOT significantly promoted sagittal mandibular growth without inducing a vertical clockwise rotation tendency, whereas AT had no significant effect on dentofacial development. Total upper airway volume increased significantly in both groups, with the increase concentrated in different regions of the upper airway depending on the group. Conclusions: In children with mild to moderate OSA and mandibular retrognathia, DOT demonstrated comparable efficacy to AT, which may be attributable to favorable anatomical remodeling of the upper airway.

Purpose Accurate segmentation of head and neck organs-at-risk (OARs) remains a critical challenge in radiotherapy planning, where current single-modality approaches often fail to address the inherent complexity of soft tissue differentiation and inter-patient anatomical variations. This study aims to develop a clinically robust auto-segmentation framework that synergistically integrates multimodal imaging features while optimizing computational efficiency. Methods We present M3-Net, a triple-interlocked deep learning architecture featuring: (1) Cross-modality fusion modules with attention-guided feature recalibration between CT density maps and MRI soft-tissue contrast; (2) A hierarchical multi-mask generator producing organ-specific, regional, and global masks through parallel encoding pathways; (3) A dual-task learning mechanism combining segmentation with deformable image registration to establish voxel-level modality correspondence. The model was trained on 200 retrospective cases (160/20/20 split) with expert-reviewed contours from a tertiary cancer center, supplemented by 10 prospective cases for clinical validation. Results M3-Net demonstrated significant improvements across three key dimensions: Efficiency: Reduced inference time by 63.6% (548±23s vs. 198±15s, p<0.001) through dynamic mask prioritization. These strategies improved the performance of M3-Net. Sixty percent of the organs achieved a Dice similarity coefficient (DSC) greater than 0.88. M3-Net performed best in 93.3% of all organs. It achieved the best average surface distance (ASD) for all organs. For independent test cases, the speed and precision can meet clinical requirements. Conclusion M3-Net establishes new state-of-the-art performance for head and neck OAR segmentation, by simultaneously addressing accuracy-efficiency tradeoffs and modality discordance. The clinically validated workflow reduces contouring time by 75% while maintaining dosimetrically significant precision, enabling rapid adoption in adaptive radiotherapy protocols.

Purpose:Accurate segmentation of head and neck organs-at-risk remains a critical challenge in radiation therapy planning, where current single-modality approaches often fail to address the inherent complexity of soft-tissue differentiation and interpatient anatomic variations. This study aims to develop a clinically robust auto-segmentation framework that synergistically integrates multimodal imaging features while optimizing computational efficiency. Methods and Materials:We present multimodality multimask and multitask auto-segmentation network (M3-Net), a triple-interlocked deep learning architecture featuring: (1) cross-modality fusion modules with attention-guided feature recalibration between computed tomography density maps and magnetic resonance imaging soft-tissue contrast; (2) a hierarchical multimask generator producing organ-specific, regional, and global masks through parallel encoding pathways; and (3) a dual-task learning mechanism combining segmentation with deformable image registration to establish voxel-level modality correspondence. The model was trained on 200 retrospective cases (160/20/20 split) with expert-reviewed contours from a tertiary cancer center, supplemented by 10 prospective cases for clinical validation. Results:M3-Net demonstrated significant improvements across 3 key dimensions: Efficiency: reduced inference time by 63.6% (548 ± 23 seconds vs 198 ± 15 seconds; P < .001) through dynamic mask prioritization. These strategies improved the performance of M3-Net. Sixty percent of the organs achieved a Dice similarity coefficient >0.88. M3-Net performed best in 93.3% of all organs. It achieved the best average surface distance for all organs. For independent test cases, the speed and precision can meet clinical requirements. Conclusions:M3-Net establishes new state-of-the-art performance for head and neck organs-at-risk segmentation, by simultaneously addressing accuracy-efficiency tradeoffs and modality discordance. The clinically validated workflow reduces contouring time by 75% while maintaining dosimetrically significant precision, enabling rapid adoption in adaptive radiation therapy protocols.

This study aims to evaluate the effects of dentofacial orthopedic treatment (DOT) and adenotonsillectomy (AT) in Obstructive Sleep Apnea (OSA) children with skeletal Class II malocclusion and adenotonsillar hypertrophy (ATH), focusing on changes in sleep respiratory function, anatomic and aerodynamic characteristics of upper airway (UA). In this retrospective study, 38 OSA children (mean age: 8.42 years, 15 females and 23 males) were included consecutively. Patients were categorized into two groups: DOT group (n = 20) and AT group (n = 18). Baseline (T0) and follow-up (T1) assessments involved polysomnography and radiological examinations to evaluate improvements in sleep quality as well as changes in craniofacial morphology and UA variables. Aerodynamic parameters such as airflow velocity, airway resistance, and wall shear stress were quantified using computational fluid dynamics. In the comparative analysis of sleep respiratory functions, there were no significant differences in apnea-hypopnea index changes between the treatment groups (DOT group: -3.72/h, AT group: -3.32/h, P = 0.600). In the DOT group, UA’s volume average enlargements were observed in the nasopharynx, palatopharynx, glossopharynx, and hypopharynx by 54.5

PurposeTo investigate the impact of platinum-based chemotherapy on long-term outcomes of T4 sinonasal adenoid cystic carcinoma (SNACC).MethodsWe retrospectively analyzed clinical data from 87 consecutive patients with T4 SNACC who underwent surgery plus radiotherapy with or without platinum-based chemotherapy in our institution between 1993 and 2019.ResultsOf the 87 cases of T4 SNACC, 57.5% (50/87) of patients underwent platinum-based chemotherapy. Overall, chemotherapy was not associated with overall survival (OS) (P = 0.814), PFS (progression-free survival) (P = 0.508), local recurrence-free survival (LRFS) (P = 0.500) or distant metastasis-free survival (DMFS) (P = 0.202) improvement. Besides, chemotherapy significantly decreased 10-year OS (27.9% vs. 58.8%, P = 0.034) compared with the no-chemotherapy group. Univariate (P = 0.383) and multivariate logistic analyses (P = 0.213) suggested that chemotherapy did not reduce the risk of distant metastasis. Furthermore, multivariate Cox regression analysis indicated that chemotherapy did not improve OS (P = 0.789) or PFS (P = 0.556).ConclusionPlatinum-based chemotherapy did not seem to provide a long-term survival advantage for patients with T4 SNACC and might be associated with worse outcomes after 5 years, although these findings need confirmation through prospective studies.

Structural abnormalities of the upper airway can lead to various complications, including obstructive sleep apnea (OSA), a condition that is increasingly diagnosed in the general population. To treat OSA, mandibular advancement devices (MADs) have emerged as a highly promising approach. Traditionally, the evaluation of MAD efficacy has been primarily qualitative. The key innovation of this study lies in the novel application of magnetic resonance imaging (MRI) to isolate and reconstruct the inspiratory phase of upper airway geometry for computational fluid dynamics (CFD) analysis, enabling precise characterization of dynamic airflow patterns during the most vulnerable period for airway collapse. In this proof-of-concept study based on a single-case dataset, fluid dynamics analysis is employed to perform quantitative analysis, providing a detailed understanding of the changes in upper airway airflow characteristics before and after the use of MADs in one OSA patient through MRI. Through quantitative assessments, this study enhances our understanding of the mechanisms underlying OSA and the therapeutic efficacy of MADs. Specifically, the findings from this case reveal that MADs can expand the minimum cross-sectional area (CSAmin) of the upper airway by 102.72%, increase the volume of the velopharynx by 61.98% and the oropharynx by 99.61%, while reducing the maximum airflow velocity by 67.09%. Furthermore, significant reductions in pressure drop, maximum viscous forces, and airway resistance were observed, alongside decreased recirculation and reversed flow in the oropharyngeal region. Additionally, MADs increased pressure in the velopharynx and oropharynx, thereby potentially mitigating the risk of upper airway collapse in OSA patients. This method can effectively isolate the inspiratory-phase upper airway model from MRI data. These preliminary results offer novel insights and strategies for the treatment of upper airway disorders from the perspective of CFD.

Sinonasal teratocarcinosarcoma (SNTCS) is a rare malignancy characterized by a highly aggressive nature. It mainly arises in the ethmoidal or maxillary sinus. SNTCS has a poor prognosis, with a mean survival rate of 55% at 2 years. Herein, we presented a case of advanced SNTCS successfully treated with surgery followed by chemoradiotherapy plus targeted therapy and reviewed the published literature on this rare entity.

AbstractBackgroundWith the coming of the aging society, the incidence of elderly nasopharyngeal carcinoma (NPC) has been increasing which may result in considerable disease burden; however, the optimal treatment strategy for elderly patients is still debatable.Methods and ResultsClinical data on 294 elderly NPC patients aged ≥70 treated between 2009 and 2019 was analyzed. Kaplan–Meier method was used to estimate overall survival (OS) and cancer‐specific survival (CSS) rates. With a median follow‐up of 53.25 months, the 5‐year estimated OS and CSS for the entire group were 59.5% and 69.8%, respectively. 146 patients died within the follow‐up period, of which recurrence + metastasis (48%) and internal medical disease unrelated to NPC (32%) are the primary causes of death. On univariable analysis, (IMRT vs. 3D‐CRT) (p = 0.001; p = 0.000), T stage (p = 0.001; p = 0.000), N stage (p = 0.013; p = 0.000) and clinical stage (p = 0.000; p = 0.000) were associated with OS and CSS; Charlson Comorbidity Index (CCI) (p = 0.016) was associated with OS. The addition of chemotherapy (CT) correlated with better CSS (p = 0.039), but did not improve OS (p = 0.056) for stage III–IV subgroup. On multivariate analysis, advanced clinical stage independently predicted poorer OS (p = 0.002) and CSS (p = 0.000). In addition, the application of IMRT was an independent protective factor on both OS (p = 0.028) and CSS (p = 0.030).ConclusionIMRT is a reasonable treatment strategy to improve survival for elderly NPC patients aged over 70 years; consideration of adding chemotherapy for elderly population should be weighed carefully.

BackgroundLaryngeal squamous cell carcinoma (LSCC) is one of the world’s most common head and neck cancer. However, the immune infiltration phenotypes of LSCC have not been well investigated.MethodsThe multi-omics data of LSCC were obtained from the TCGA (n=111) and GEO (n=57) datasets. The infiltrations of the 24 immune cell populations were calculated using the GSVA method. Then LSCC samples with different immune cell infiltrating patterns were clustered, and the multi-omics differences were investigated.ResultsPatients were clustered into the high-infiltration and low-infiltration groups. The infiltration scores of most immune cells were higher in the high-infiltration group. Patients with high-infiltration phenotype have high N and TNM stages but better survival, as well as less mutated COL11A1 and MUC17. Common targets of immunotherapies such as PD1, PDL1, LAG3, and CTLA4 were significantly up-regulated in the high-infiltration group. The differentially expressed genes were mainly enriched in several immune-related GOs and KEGG pathways. Based on the genes, miRNAs, and lncRNAs differentially expressed in both the TCGA and GEO cohorts, we built a ceRNA network, in which BTN3A1, CCR1, miR-149-5p, and so on, located at the center. A predictive model was also constructed to calculate a patient’s immune infiltration phenotype using 16 genes’ expression values, showing excellent accuracy and specificity in the TCGA and GEO cohorts.ConclusionsIn this study, the immune infiltration phenotypes of LSCC and the corresponding multi-omics differences were explored. Our model might be valuable to predicting immunotherapy’s outcome.

PURPOSE:To study the prevalence of nodal metastases in sinonasal adenoid cystic carcinoma (SNACC) and to evaluate whether prophylactic neck irradiation (PNI) should be performed in patients with clinical N0 (cN0) disease.PATIENTS AND METHODS:Between April 1992 and November 2020, 166 patients with SNACC who had undergone radiotherapy at our department were retrospectively analyzed. The median follow-up time was 71.3 months.RESULTS:Among 166 cases of SNACC, a total of 13 (7.8%) had retropharyngeal or cervical nodal metastasis and 93% (12/13) cases occurred in patients with advanced T stage (T3-T4). Levels VIIa, Ib, and IIa were the most common sites of initial nodal involvement. Only 1.2% (2/166) of patients presented late neck recurrence. Lymph node metastasis independently predicted a poor progression-free survival (PFS) (P = 0.017) but had no impact on overall survival (OS) (P = 0.38). PNI was performed on 36% (55/153) of cN0 patients. The OS (P = 0.42), PFS (P = 0.59), nodal recurrence-free survival (NRFS) (P = 0.46) and distant metastasis-free survival (DMFS) (P = 0.63) rates showed no significant difference between cases with and without PNI. Furthermore, cN0 patients with T4b (P = 0.53; P = 0.61), tumor origin from maxillary sinus (P = 0.55; P = 0.53) or nasopharynx involvement (P = 0.56; P = 0.60) showed no extended OS or PFS associated with PNI.CONCLUSIONS:Regardless of the T stage or the site of origin, prophylactic neck irradiation (PNI) for cN0 patients did not provide any benefit on OS and PFS, suggesting that its application on such patients is not warranted unless there is clinical suspicion.

Transient receptor potential channel 6 (TRPC6) is a receptor-operated Ca2+ channel that plays an important role in Ca2+ influx in the majority of non-excitable cells and influences calcium signalling and cellular responses. Therefore, the purpose of the present study was to gain insight into the role of TRPC6 in the osteogenesis of periodontal ligament cells (PDLCs). By western blot and immunohistochemical staining, the protein level of TRPC6 was found to be increased in a time-dependent manner during osteoblastic differentiation of PDLCs. In addition, the TRPC6 inhibitor SKF96365 was used to block the function of TRPC6 and inhibit osteoblastic differentiation of PDLCs. The TRPC6 activator hyperforin dicyclohexylammonium salt (hyperforin DCHA) was used to activate TRPC6 and promote osteoblastic differentiation of PDLCs. In vivo, wild-type mice showed better bone regeneration than TRPC6-/- mice, suggesting that TRPC6 has notable osteogenic induction properties and is important for bone defect repair. In conclusion, the current data demonstrated that TRPC6 plays a significant role in osteoblastic differentiation of PDLCs, suggesting that it may be a promising therapeutic target in osteogenesis.

Laryngeal squamous cell carcinoma (LSCC) is an aggressive malignancy with metastatic potential and high mortality worldwide. Matrix metalloproteinases (MMPs) are a group of extracellular proteolytic enzymes. Although MMPs have been proved to be essential in the process of tumor migration and metastasis in most types of carcinomas, the expression and function of MMP2/3 in LSCC remain unknown. Here, we investigated the roles of MMP2/3 in LSCC and elucidated the underlying mechanism. We found that levels of MMP2/3 were significantly higher in clinical LSCC samples than in paired normal sample examined by real-time polymerase chain reaction and western blot assays. Moreover, overexpression of MMP2/3 promoted the proliferation and migration of LSCC cells by Cell Counting Kit-8, transwell, and scratch wound-healing assays in vitro. Furthermore, levels of epithelial cell markers (E-cadherin and occludin) were decreased following MMP2/3 overexpression, with increased levels of mesenchymal cell markers (N-cadherin and vimentin), suggesting the involvement of epithelial-mesenchymal transformation (EMT) process in MMP2/3-mediated LSCC cell migration. By using short hairpin RNA, knockdown of MMP2/3 expression inhibited the proliferation, migration, and EMT process in LSCC cells in vitro. More importantly, we confirmed that MMP2/3 promoted LSCC in the PI3K/Akt-NF-κB-dependent manner. This study provides insight into MMP2/3-mediated LSCC development and lays a foundation for potential pharmacological targets to LSCC.

Background To investigate the management and outcomes of patients with lacrimal sac squamous cell carcinoma (SCC). Methods This retrospective study examined 69 lacrimal sac SCC cases treated at our hospital between 1992 and 2017. The potential risk factors for prognosis, a new staging method, treatment outcomes, and complications were investigated. Results The 5-year overall survival (OS) and progression-free survival (PFS) were 87.6 +/- 4.8% and 76.3 +/- 6.4%, respectively. Positive lymph node was associated with worse OS and PFS. We divided lacrimal sac SCC into four clinical stages, with significant differences in OS (P = .026) and PFS (P = .042) among each stage. Definitive radiotherapy was equivalent to surgery plus radiotherapy in 26.1% (18/69) of cases, and the incidence of complications was not higher. Conclusions Lymph node status was a key factor in determining outcomes. Our staging method could effectively classify tumor stage and predict prognosis, which can contribute to optimizing treatment regimes. Radiotherapy played an important role in treatment.

Background: Most previous studies are separate dosimetric analyses of conductive or sensorineural hearing loss, and they are not conducive to a comprehensive assessment of auditory radiation damage. Aims/objectives: Our study aimed to evaluate the long-term incidence of sensorineural hearing loss (SNHL) or conductive hearing loss (CHL) in patients with nasopharyngeal carcinoma (NPC) after intensity-modulated radiation therapy (IMRT), and to investigate the relationship between SNHL or CHL and patient factors, treatment-related factors, and radiation dose parameters. Material and methods: Seventy patients (117 ears) with NPC, who were also treated with IMRT in our hospital from 2006 to 2014, were retrospectively analyzed. Radiation doses to the Eustachian tube (ET), middle ear (ME), cochlear (Co), and internal auditory canal (IAC) were assessed. Pure tone audiometry and impedance audiometry were performed before and during the follow-up period. The relationships between low-frequencies (0.5-2 kHz) or high-frequency (4 kHz) SNHL/CHL and radiotherapy dose parameters were analyzed. Results: Of the 117 ears studied, 7.69% had low-frequency SNHL, 35.9% had high-frequency SNHL, 23.93% had low-frequency CHL, and 18.80% had high-frequency CHL. The incidence of high-frequency CHL was higher in the T4 group than in the T (1-3) group (p < .05). When IAC D-max > 42.13 Gy or IAC D-mean > 32.71 Gy, the risk of high-frequency SNHL increased in NPC patients. When ME D-max > 44.27 Gy, ME D-mean > 29.28 Gy, or ET D-max > 57.23 Gy, the risk of high-frequency CHL in NPC patients increased. Conclusions and significance: SNHL and CHL remain common ear complications after IMRT for NPC. IAC D-max, IAC D-mean, ME D-max,D- ME D-mean, and ET D-max all need to be carefully considered during the IMRT treatment protocol.

Objective To investigate the clinical features and treatment strategies of primary diffuse large B cell lymphoma (DLBCL) of nasal cavity and paranasal sinuses.Methods The clinical features and prognostic factors of 30 patients who were newly diagnosed as primary DLBCL of nasal cavity and paranasal sinuses from January 2007 to December 2014 were retrospectively analyzed.Results Among 30 patients,21 cases were male and 9 were female;the median age was 63 years;26 patients were Ann Arbor stage Ⅰ,4 patients were stage Ⅱ,none presented with B symptoms.All patients received chemotherapy and radiotherapy;8 patients received R-CHOP and 22 patients received CHOP-like-based chemotherapy regimens with a median of 4 cycles.Patients were treated with three-dimensional conformal radiotherapy with a dose of 36 ～54 Gy(median dose of 46.8 Gy).One patient received central nervous system(CNS) prophylaxis during the treatment.There were 22 patients in complete remission,6 in partial remission,one in progressive disease,and one died of upper gastrointestinal hemorrhage during radiotherapy.With a median follow-up of 72 months,the 5-year survival rate was 56.7％ (95％ CI:47.7％ to 65.7％) and two CNS relapses occurred.Conclusions Patients with primary DLBCL of nasal cavity and paranasal sinuses commonly present with localized disease but have a poor prognosis.At present,R-CHOP chemotherapy regimen is mainly used for the treatment of the disease and local radiotherapy also has an important role.CNS prophylaxis should not be routinely used in these patients.

Objective To investigate the protective effects of reducing average radiation dose and increasing protective weight on the auditory system (tympanic cavity,the bony portion of eustachian tube,vestibule,and cochlea) during intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).Methods The planning system (ADAC Pinnacle3 8.0m) with direct machine parameter optimization was used to optimize the IMRT planning for 40 patients with NPC (stage Ⅰ + Ⅱ:20 patients ;stage Ⅲ + Ⅳ:20 patients).Without reducing the radiation dose for target volume,the IMRT planning was optimized by limiting the average dose administered to the auditory system or increasing the protective weight for the protected organs in auditory system.The protective effects were assessed by analyzing the average dose received by the auditory system.Results After limiting the average dose administered to the auditory system without reducing the radiation dose for target volume,the average dose received by the auditory system was significantly reduced (3855.5-5391.3 Gy vs 2960.3-4559.6 Gy,P =0.000 for all) ; when the protective weight for the auditory system was increased,the average dose received by the auditory system was even more reduced (3855.5-5391.3 Gy vs 2725.4-4271.4 Gy,P =0.000 for all).For all three regimens,the average dose was significantly higher in stage Ⅲ + Ⅳ patients than in stage Ⅰ + Ⅱ patients (P =0.000 for all).Conclusions For the IMRT planning for NPC,limiting the average dose administered to the auditory system can greatly reduce the average dose received by the auditory system,and increasing the protective weight for the auditory system can further reduce the average dose received by the auditory system.However,the protective effect on the auditory system may be reduced as the stage of NPC increases.

OBJECTIVE To evaluate the therapeutic effect of malignant tumor of nasal cavity and sinus that based on modern radiotherapy. METHOD Two hundred cases of malignant tumor of nasal cavity and sinus were retrospectively analyzed from 2004 to 2007. All the cases were location by CT simulator system and were treated with three dimensional conformal radiotherapy. RESULT Among malignant tumor of nasal cavity and sinus, the incidence for locations was nasal cavity > maxillary sinus > ethmoid sinus > sphenoid sinus; the incidence for the type of pathology was squamous cell carcinoma > adenocarcinoma > olfactory neuroblastoma and olfactory esthesioneuroepithelioma > malignant melanoma > rhabdomyosarcoma; the incidence for general metastasis was rhabdomyosarcoma > malignant melanoma > adenocarcinoma, inverted papilloma and malignant changes > squamous cell carcinoma, olfactory neuroblastoma and olfactory esthesioneuroepithelioma. No severe radiation-related complication were found. CONCLUSION Clinical stage, pathological type were the important factors effecting the prognosis of patients with malignant tumor of nasal cavity and sinus. Three dimensional conformal radiotherapy based on CT simulator system could improve therapeutic effect and protect the normal tissue very well.

Purpose This study evaluates the difference in damage to middle ear function with CRT and IMRT techniques in the treatment of nasopharyngeal carcinoma (NPC). We explore the isthmus of the Eustachian tube (ET) as the key anatomic site for the prevention of radiation-induced otitis media with effusion. Methods and materials Eighty-two patients with NPC were divided into two groups: 40 patients treated with CRT and 42 patients treated with IMRT. The difference between dosage over the middle ear cavity and the isthmus of the ET was evaluated in both CRT group and IMRT group. All patients underwent hearing tests including pure tone audiometry and impedance audiometry before and after RT. Results The dosage difference to the middle ear cavity and isthmus between these two groups was statistically significant (p<0.05). The difference in hearing test results between these two groups was also statistically significant (p<0.05). If we limited the dose to the middle ear cavity under 34Gy and the dose to the isthmus under 53Gy with IMRT, we may decrease radiation-induced OME even with the larger 2.25Gy fraction size. Conclusions IMRT may have better protected the middle ear function compared with the CRT technique, even with larger fraction sizes than for the conventional CRT technique.