Objective To explore the treatment procedure of pediatric vaginal rhabdomyosarcoma ( RMS) using 60 Co high?dose?rate three?dimensional ( 3D ) brachytherapy, and to analyze its dosimetric feasibility. Methods Computed tomography ( CT ) images were collected from five children undergoing radiotherapy for vaginal RMS. Three treatment plans were designed:plan A using 3D conformal radiotherapy with external beam irradiation, plan B using brachytherapy, and plan C using brachytherapy combined with external beam irradiation. Dosimetric parameters for clinical target volume ( CTV ) and organs at risk ( OARs ) were evaluated based on EQD 2 and analyzed using one ? way analysis of variance . Results Compared with plan A, plan C had significantly larger D90, D50, and Dmean for CTV ( all P=0?00), significantly lower doses to the rectum, bladder, and femoral head, and a significantly higher dose to the ovary ( all P=0?00) . Compared with plan B, plan C had a larger D90 for CTV, smaller D50 and Dmean for CTV, a lower dose to the ovary, and higher doses to the rectum, bladder, and femoral head. Among the three plans, plan B had the smallest D2 cm3 for the rectum and bladder. Conclusions The optimal radiotherapy plan for pediatric vaginal RMS should be based on the primary tumor location and residual tumor after surgery. CT image?guided 60 Co high?dose?rate 3D brachytherapy is convenient, effective, and well tolerated by children. It also achieves a high dose to CTV as well as good protection of normal tissue.

Radiation-induced lung injury (RILI) is a common complication after radiotherapy for lung cancer and alternative thoracic malignant tumors, while ferroptosis is a regulated cell death triggered by iron-dependent membrane lipid peroxidation. In this article, the relationship between RILI and ferroptosis was investigated from oxidative damage induced by reactive oxygen species, antioxidant network and iron homeostasis regulated by nuclear factor erythroid 2-related factor 2(Nrf2) as well as transforming growth factor involved in the inflammatory response, aiming to mitigate or inhibit the occurrence of RILI through regulating ferroptosis, thereby improving clinical prognosis of patients undergoing radiotherapy.

AIM: To study the relation of acute radiation-induced oral mucositis to fungal infection and evaluate the effect of fluconazole in the treatment of patients with fungal infection.　METHODS: Seventy-one patients (M 42, F 29; 52 a± s 41 a,11-76 a) with large area of oral mucosas irradiated were into this study. When most serious mucositis, the patients' oral mucosas were checked, 32 patients with fungal infection were treated with fluconazole (fluconazole 100 mg, po, qd×5 d or 150 mg,iv,gtt×3 d).　RESULTS: The rate of fungal infection was 45%, the most of patients were infected by candida albicans. Degrees of mucositis between the patients with fungal infection to the patients without fungal infection were significantly different (P<0.05). The patients with fungal infection were treated with fluconazole. Degree of mucositis between the pretreated patients and post-treated patients were significantly different (P<0.05).　CONCLUSION: The serious acute radiation-induced oral mucositis has significantly related with fungal infection. The patients with fungus infection treated with antifungal agents (fluconazole) can significantly relieve the reaction of acute radiation-induced oral mucositis.

Objective To analyze the differences between calculated and actual volumes of regions of interest ( ROIs) in three treatment planning systems ( TPSs):PrecisePlan, Xio, and Oncentra, to transfer different ROIs and compare their calculated volume between the three TPSs, and to provide a basis for clinical application. Methods Different sizes of ROIs were delineated on 5 sets of computed tomography ( CT) images with different slice thickness. Square and round regions with different slice numbers were contoured in a homogeneous phantom. Three groups of patients ( n=5) with head and neck tumor, chest and abdomen tumor, and pelvic tumor, respectively, were enrolled as subjects. All the ROIs were independently transferred back and forth between three TPSs and different workstations with the same system in DICOM RT format. The changes in actual and calculated ROI volumes were evaluated after back and forth transfer. Results There was a significant positive linear correlation between the calculated volume, slice thickness, slice number, and actual volume of ROI in each TPS ( PrecisePlan:R2=0. 994, P<0. 01;Xio:R2=0. 997, P<0. 01;Oncentra:R2=0. 995, P<0. 01) . There were significant differences in all calculated ROI volumes of the head, chest and abdomen between the three TPS ( P<0. 05) except for the calculated ROI volumes of the chest and abdomen between Oncentra and Xio ( P=0. 114 ) . Conclusions The variations in volume calculation algorithm and slice thickness are the main causes of differences in calculated ROI volume. Particularly, small?volume ROIs have the greatest variation in calculated volume. To avoid a secondary reconstruction of ROI volume, it is recommended to transfer ROI back and forth between dose calculation workstations with the same TPS.

Objective:To assess the feasibility of deformable image registration (DIR) in evaluating cumulative dose distribution of bladder and rectum of cervical cancer patients during helical tomotherapy (HT)-based intensity-modulated radiotherapy (IMRT) and high-dose-rate(HDR) brachytherapy.Methods:Clinical data of 18 patients were retrospectively analyzed. Cumulative bladder/rectum D 2cm 3 and high-risk clinical target volume (HR-CTV) D 90% parameters were calculated and compared to two direct parameter-adding methods with two registration-adding methods. Equivalent uniform dose (EUD group) and overlapping high dose (OHD group) methods were employed as parameter-adding methods. The registration-adding methods including rigid image registration (RIR group) and deformable image registration (DIR group) were adopted based on a commercial image registration software (MIM Maestro ?). The dice similarity coefficient (DSC) and mean distance to agreement (MDA) were measured to assess the accuracy of RIR and DIR. Results:In the EUD, OHD, RIR and DIR groups, the cumulative doses of bladder/rectum D 2cm 3 and HR-CTV D 90% were (80.11±3.59) Gy (EQD 2Gy), (82.23±3.46) Gy (EQD 2Gy), (80.99±6.01) Gy (EQD 2Gy) and (81.19±3.11) Gy (EQD 2Gy)( P=0.516); (72.90±3.58) Gy (EQD 2Gy), (73.83±4.28) Gy (EQD 2Gy), (72.45±6.05) Gy (EQD 2Gy) and (71.98±2.89) Gy (EQD 2Gy)( P=0.625), and (85.51±2.91) Gy (EQD 2Gy), (87.65±3.46) Gy (EQD 2Gy), (81.53±3.63) Gy (EQD 2Gy) and (85.81±3.30) Gy (EQD 2Gy)( P<0.001), respectively. The mean DSC of the bladder, rectum and HR-CTV were 0.69, 0.65 and 0.63 with RIR; and 0.85, 0.81 and 0.78 with DIR ( P<0.001), respectively. In DIR, the average MDA of bladder, rectum, and HR-CTV were 2.88, 2.48 and 2.66 mm, respectively. Conclusions:The cumulative DVH parameters among 4 groups show no significant difference in the bladder/rectum D 2cm 3/D 0.2cm 3. Since the DIR group achieves satisfactory volume matching of greater than 0.8 with DSC analysis, it can yield acceptable results for clinical application between HT IMRT and HDR BT for cervical cancer.

Esophageal cancer is one of the most common malignant tumors in China and dysphagia caused by malignant stenosis is the most common symptom of advanced esophageal cancer. The inability to eat orally seriously affects the quality of life of patients with advanced esophageal cancer, and poor nutritional status caused by dysphagia limits the implementation of standard treatment programs such as radiotherapy and chemotherapy, resulting in a decline in survival. The 125I radioactive stent is a novel treatment for malignant stenosis. Studies have shown that it can relieve dysphagia and prolong patients' survival compared to traditional esophageal stents. In this article, the treatment of malignant stenosis in advanced esophageal cancer and the clinical application progress of 125I radioactive stents were reviewed.

Objective:To investigate the clinical features of pediatric patients with intracranial primary non-germinomatous germ cell tumors (NGGCT) and evaluate the treatment outcomes and prognostic factors of NGGCT.Methods:Clinical data of 40 children with NGGCT who were treated with radiotherapy (RT) at our department between November 2008 and June 2019 were retrospectively analyzed. Ninety percent of them received craniospinal irradiation (CSI). All children received platinum-based chemotherapy. Survival analysis was conducted using the Kaplan-Meier estimate. The prognostic factors were analyzed by log-rank test.Results:The primary sites were pineal gland, sellar / suprasellar region and basal ganglia. The median age of onset was 108 months (20-204 months). The median follow-up time was 33 months (8-131 months), and the 3-year and 5-year overall survival (OS) rates were 82.0%. The 3-year and 5-year progression-free survival (PFS) rates were 78.6% and 73.0%. Univariate analysis showed that increased alpha-fetoprotein (AFP) ( P=0.02), age at first diagnosis>10 years ( P=0.006), metastasis at first diagnosis ( P<0.001), and the pathological type (choriocarcinoma, yolk sac tumor and / or embryonal carcinoma) ( P=0.036) were independent adverse prognostic factors. Conclusions:Increased AFP, age>10 years at first diagnosis, tumor metastasis and pathological type were independent adverse prognostic factors of NGGCT. The overall prognosis of NGGCT children is worse than that of their counterparts with germinoma, and multidisciplinary intensive therapy is needed to improve survival.

Objective:To investigate the clinic opathological features, treatment and prognosis of children newly diagnosed with ependymoma.Methods:Clinical data of 127 pediatric ependymoma (EPN) patients (0-16 years old) treated with tumor resection and postoperative radiotherapy at Xinhua Hospital Affiliated to Shanghai Jiao Tong University between 2001 and 2021 were retrospectively analyzed. Among them, 53 children were female and 74 were male. Local control (LR), event-free survival (EFS) and overall survival (OS) rates were analyzed by Kaplan-Meier method. The relationship between clinic opathological factors and clinical prognosis, and the effect of treatment on clinical prognosis of patients were analyzed by Cox proportional hazards model.Results:At a median follow-up time of 29 months (3-251 months), the 3-year OS and EFS rates were 89.5% and 71.5%, respectively. For patients undergoing incomplete resection followed by postoperative adjuvant radiotherapy, the 3-year LR, OS and EFS rates were 78.3%, 65.8% and 85.7%, respectively. A total of 43 children were aged <3 years old when diagnosed and 84 aged ≥3 years old. The interval time between surgery and radiotherapy in children aged <3 years old was 91 d, and 35.5 d in those aged ≥3 years old ( P<0.001). For patients <3 years old, the median EFS was 90 months when initiating radiotherapy within ≤70 d after surgery, compared to 43 months for those who initiated radiotherapy at >70 d after surgery ( P=0.053). According to fifth edition of the WHO classification of tumors of the central nervous system (WHO CNS5), 39 children were classified as posterior fossa ependymoma group A (PFA group). The OS and EFS rates in the PFA group were significantly less than those in other groups (3-year OS rate were 69.2% vs. 94.6%, P<0.001; 3-year EFS rate were 46.9% vs. 79.1%, P<0.001). In the PFA group, 12 patients received postoperative adjuvant chemotherapy, 14 did not receive chemotherapy, and whether chemotherapy was given was unknown in 13 cases. No significant differences were observed in OS and EFS between patients treated with and without chemotherapy ( P=0.260, P=0.730). Univariate Cox analysis showed that tumor location and WHO CNS5 molecular classification were significantly associated with EFS, and WHO CNS5 molecular classification was significantly correlated with OS. Multivariate Cox analysis showed that tumor location in the posterior fossa was an independent risk factor for EFS ( HR=2.72, 95% CI=1.1~6.71, P=0.03). Conclusions:Patients newly diagnosed with pediatric ependymoma can obtain favorable survival after surgery combined with postoperative adjuvant radiotherapy. Patients with residual tumors can achieve favorable LC and survival after postoperative adjuvant radiotherapy. Delaying of radiotherapy tends to lead to poor survival for patients aged <3 years old when diagnosed. Children in the PFA group obtain worse prognosis compared to their counterparts in other groups. The tumor location in the posterior fossa is an independent risk factor for pediatric ependymoma.