Objective To compare the dosimetric disparities among static intensity-modulated radiotherapy(IMRT),volumetric modulated arc therapy(VMAT),and tomotherapy(TOMO)techniques in cervical cancer radiotherapy for providing data support for clinical decision-making scheme of radiotherapy.Methods The clinical data of 19 cervical cancer patients,treated at the Affiliated Cancer Hospital and Institute of Guangzhou Medical University from February to May in 2024,were analyzed.Three plans were devised for each case using IMRT,VMAT,and TOMO techniques,followed by dosimetric evaluation in terms of various metrics such as dose volume parameters of the target areas as well as organs-at-risk(OAR),conformity index(CI),homogeneity index(HI),and delivery time.Results All 3 plans met the clinical prescription requirements for the target areas.Compared with static IMRT and VMAT,TOMO had significantly lower Dmean and Dmaxof PCTV and PGTVnd.For OAR,TOMO demonstrated significant advantages over IMRT and VMAT in the Dmean of the bladder,the Dmean,Dmax,V30,V40of the rectum,the Dmean,Dmax,V20,V30of left and right femoral heads,and the Dmean,V20,V50of the pelvis(P<0.05).In addition,the TOMO group showed significantly higher CI for both PCTV and PGTVnd as compared with IMRT and VMAT groups,and lower PGTVnd HI than IMRT group(all P<0.05).Although there was trivial difference among 3 groups in term of PCTV HI,TOMO group performed slightly better than the other two groups.Notably,VMAT technique had the shortest treatment time.Conclusion In various treatment modalities for cervical cancer,TOMO is superior to IMRT and VMAT in terms of target dose coverage,OAR dose distribution,CI,and HI.However,VMAT has the highest efficiency.

Objective To compare the dosimetric disparities among static intensity-modulated radiotherapy(IMRT),volumetric modulated arc therapy(VMAT),and tomotherapy(TOMO)techniques in cervical cancer radiotherapy for providing data support for clinical decision-making scheme of radiotherapy.Methods The clinical data of 19 cervical cancer patients,treated at the Affiliated Cancer Hospital and Institute of Guangzhou Medical University from February to May in 2024,were analyzed.Three plans were devised for each case using IMRT,VMAT,and TOMO techniques,followed by dosimetric evaluation in terms of various metrics such as dose volume parameters of the target areas as well as organs-at-risk(OAR),conformity index(CI),homogeneity index(HI),and delivery time.Results All 3 plans met the clinical prescription requirements for the target areas.Compared with static IMRT and VMAT,TOMO had significantly lower Dmean and Dmaxof PCTV and PGTVnd.For OAR,TOMO demonstrated significant advantages over IMRT and VMAT in the Dmean of the bladder,the Dmean,Dmax,V30,V40of the rectum,the Dmean,Dmax,V20,V30of left and right femoral heads,and the Dmean,V20,V50of the pelvis(P<0.05).In addition,the TOMO group showed significantly higher CI for both PCTV and PGTVnd as compared with IMRT and VMAT groups,and lower PGTVnd HI than IMRT group(all P<0.05).Although there was trivial difference among 3 groups in term of PCTV HI,TOMO group performed slightly better than the other two groups.Notably,VMAT technique had the shortest treatment time.Conclusion In various treatment modalities for cervical cancer,TOMO is superior to IMRT and VMAT in terms of target dose coverage,OAR dose distribution,CI,and HI.However,VMAT has the highest efficiency.

Objective:To explore the therapeutic efficacy and toxicity of oral Etoposide chemotherapy in children with disseminated medulloblastoma (MB) after the standard treatment plan.Methods:The clinical data of 86 children with disseminated MB admitted in the Department of Pediatrics, Beijing Shijitan Hospital of Capital Medical University from January 2016 to May 2020 were analyzed retrospectively.The median age of children was 8.8 (3.0-16.7) years old.Among them, 33 children treated with maintenance chemotherapy via oral Etoposide were included in the chemotherapy group, and 53 children without oral maintenance chemotherapy were included in the non-chemotherapy group.The gender distribution, surgical resection range, pathological type, molecular classification, postoperative mutism, M-stage and survival[progression-free survival (PFS) and overall survival (OS)] of the 2 groups were compared.The main adverse events of oral Etoposide chemotherapy were recorded. Chi- square test is used for data comparison, Kaplan-Meier method was used to plot the survival curve of disseminated MB patients, followed by the Log- rank test. Results:There were no significant differences in gender, surgical resection range, pathological type, molecular typing, postoperative mutism and M-stage between the 2 groups (all P>0.05). Of 86 patients, the median PFS and OS were 3.0 (0.2-6.3) years, and 3.6 (0.5-6.3) years, respectively.Twenty five cases (29.1%) relapsed, 13 cases (15.1%) died.The 3-year[(65.8±6.8)% vs.(82.0±7.3)%] and 5-year PFS[(56.8±7.7)% vs.(82.0±7.3)%] in non-chemotherapy group were significantly lower than those of chemotherapy group ( P=0.037). The 3-year[(81.6±5.6)% vs.100.0%] and 5-year OS[(71.2±7.7)% vs.(92.3±7.4)%] in non-chemotherapy group were significantly lower than those of chemotherapy group ( P=0.025). Among the children with the SHH subtype, the PFS of children with oral Etoposide maintenance chemotherapy after a regular treatment was significantly higher than that without oral maintenance chemotherapy (100.0% vs.57.1%)( P=0.021). The major adverse events of oral Etoposide were myelosuppression and gastrointestinal symptoms, which were mostly relieved after a symptomatic treatment.Treatment-related deaths were not reported. Conclusions:The prognosis of disseminated MB in children is relatively poor.Oral Etoposide for maintenance therapy after a standard treatment is beneficial in reducing relapse and improving the 5-year survival, which is well tolerated.

Objective:Summarizing the clinical characteristics of extraneural metastasis in childhood medulloblastoma.Methods:A total of 616 cases with medulloblastoma treated in Beijing Shijitan Hospital from April 2010 to April 2019 were analyzed retrospectively, among which 11 cases developed extraneural metastasis.The age of onset, location and time of extraneural metastasis, pathological and molecular typing, treatment and prognosis were descriptively analyzed.The differences of blood biochemical indexes between medulloblastoma cases with and without extraneural metastasis were statistically analyzed by t test. Results:As of February 2020, the median follow-up period was 16 months (ranging from 3 to 69 months). Eleven cases, including 8 males and 3 females, were diagnosed with extraneural metastasis, with the incidence being about 1.8%.The median age of medulloblastoma was 6 years (2-10 years), and the median age at presentation of extraneural metastasis was 7 years (2-12 years). Extraneural metastasis occurred from 0.5 months to 38.0 months after the operation, and the affected location includes bone (6 cases), bone marrow (3 cases), lung (3 cases), pelvis (2 cases) and abdominal cavity (1 case). In these patients, the range of lactic dehydrogenase (LDH) was (2 298.00±1 570.70) U/L and neuron-specific enolase (NSE) was (201.00±68.34) μg/L, which were significantly higher than those in patients without extraneural metastasis [(249.50±46.28) U/L and (22.80±7.12) μg/L, all P<0.05]. Partial patients were treated with chemotherapy, while the majority of them were treated with palliative treatment in the terminal stage, with the survival period mostly less than 10 months. Conclusions:Although there is a low incidence of extraneural metastasis in medulloblastoma pediatric patients, the prognosis of these patients with extraneural metastasis is poor and most of them would die within one year.The most common sites include bone, followed by bone marrow and lungs, which may be related to the spread of cerebrospinal fluid and the increased levels of LDH and NSE.

Objective:To explore the effect of neutrophil-lymphocyte ratio (NLR) at the initial visit on the survival of children with newly diagnosed medulloblastoma (MB).Methods:This was a case-control study involving 61 children with newly diagnosed MB at the Department of Pediatrics, Beijing Shijitan Hospital, Capital Medical University from August 2018 to January 2020 .The blood cell counts, lymphocyte subsets and immunoglobulin in the periphe-ral blood were measured to calculate NLR at the initial visit.Based on the cut-off value determined by receiver opera-ting characteristic (ROC) curve, patients were divided into high NLR group (≥ 2.07, n=21) and low NLR group (<2.07, n=40). The progression-free survival (PFS) and overall survival (OS) between 2 groups were analyzed by the Kaplan-Meier method, followed by Log- rank test.The correlation between NLR at the initial visit with clinical characteristics, lymphocyte subsets and immunoglobulin of children with newly diagnosed MB was analyzed.Differences between groups were compared by the Chi- square test, Mann- Whitney U test and independent sample t test. Results:The survival analysis showed that the relapse rate (38.1% vs.10.0%, χ2=6.879, P=0.016) and mortality rate (19.0% vs.0, χ2=8.154, P=0.011) were significantly higher in high NLR group than those of low NLR group.PFS (12 months vs.19 months, χ2=9.775, P=0.002) and OS (19 months vs.20 months, χ2=8.432, P=0.004) were significantly shorter in high NLR group than those of low NLR group.No significant differences in clinical characteristics were detected between groups (all P>0.05). Compared with low NLR group, the percentage of T lymphocyte[(67.93±6.37)% vs.(73.38±8.08)%, t=2.886, df=48.865, P=0.006], T helper cells (Th)[(30.86±5.53)% vs.(34.29±7.44)%, t=2.037, df=51.981, P=0.047], and T suppressor cells (Ts)[(27.39±5.50)% vs.(30.84±6.58)%, t=2.164, df=47.581, P=0.035] were significantly lower in high NLR group.Spearman correlation analysis showed a negative correlation between NLR and T lymphocyte count ( r=-0.303, P=0.018), and Ts lymphocyte count ( r=-0.260, P=0.043). Conclusions:Children with newly diagnosed MB expressing a high level of NLR had a poor prognosis, which may be associated with T lymphocyte and Ts lymphocyte.

Objective:To analyze the clinical characteristics of children with medulloblastoma (MB) complicated with incomplete intestinal obstruction, and to explore the possible pathogenesis of intestinal obstruction in children with MB.Methods:A total of 409 children with MB admitted to the Department of Pediatrics of Beijing Shijitan Hospital, Capital Medical University from October 2014 to January 2019 were recruited into this study, and the clinical data of children with incomplete intestinal obstruction were collected and analyzed retrospectively.A comparison was performed between these children and those without intestinal obstruction who were treated at the same time.The chi- squared test and Logistic regression analysis were adopted to explore the pathogenesis of intestinal obstruction.The overall survival (OS) rate was calculated with the Kaplan-Meier method. Results:There were 11 cases of 409 children with MB complicated with incomplete intestinal obstruction in total, with the morbidity of 2.7%, they were all over 3 years old, with the median age of 8.7 years, and a male-to-female ratio of 4.5∶1.The incomplete intestinal obstruction in all cases occurred during the first cycle of maintenance chemotherapy after radiotherapy.All these patients could be reco-vered after conservative treatment, and no incomplete intestinal obstruction occurred in the subsequent chemotherapy.The results of Logistic regression analysis showed that there was a correlation between age and the development of incomplete intestinal obstruction ( P<0.05). The 2-year OS rate of MB patients complicated with incomplete intestinal obstruction was (87.5±11.7)%, and that of patients without incomplete intestinal obstruction during the same period was (92.8±1.6)%, which showed that the difference between the two group was not statistically significant ( P>0.05). Conclusions:Incomplete intestinal obstruction would occur in all MB patients within 2 months after radiotherapy, and children more than 3 years old are more prone to suffer from this disease.Therefore, it can be supposed that gastrointestinal mucosa was damaged under the double attack of radiotherapy and Vincristine, which slowed down the intestinal peristalsis, thus inducing intestinal obstruction.

Objective:To explore the laboratory characteristics and diagnostic methods for therapy-related acute megakaryocytic leukemia (t-AMKL).Methods:The data of one child with acute lymphoblastic leukemia (ALL) in the Blood Disease Hospital of Chinese Academy of Medical Sciences & Peking Union Medical College in September 2014 was retrospectively analyzed. After inducing remission for more than 43 months, the child was diagnosed as t-AMKL.Results:After the diagnosis of ALL, the child was given chemotherapy with standard childhood ALL regimen. After 43 months, t-AMKL was diagnosed by comprehensive morphology, cytogenetics, and molecular biology. Bone marrow morphology showed that the proportion of primitive cells was 0.44; flow cytometry showed the phenotype was abnormal myeloid primitive cells; the pathology result showed that the abnormal cells weakly expressed CD42b and CD61; the electron microscopy showed platelet peroxidase (PPO)-positive and myeloperoxidase (MPO)-negative; the bone marrow immunohistochemistry showed the positive rate of CD41 was 34%; the child had a complex karyotype. After reviewing his medical history, he was diagnosed as t-AMKL.Conclusion:The t-AMKL is relatively rare, and it is helpful to improve the prognosis of patients by completing the relevant examinations for early diagnosis.

Objective: To investigate the prognostic factors and survival status of children with medulloblastoma (MB) by using retrospective analysis. Methods: From February 2011 to December 2017, 224 children with newly-diagnosed MB were enrolled in this study, which was carried out at Department of Pediatrics, Beijing Shijitan Hospital, Capital Medical University.The overall survival (OS) rate and progression-free survival (PFS) rate were calcula-ted by using Kaplan-Meier method, the difference between 2 groups was tested by Log-rank method, and prognostic factors were analyzed by COX regression. Results: Until December 30, 2018, the median survival time of all these 224 children was 4.1 years, the survival rate was 74.6%, complete response (CR) rate was 60.3%, and the relapse rate was 1.7%. The 5-year PFS rate and 5- year OS rate of all patients were (58.2±3.6)% and (72.5±3.3)%, respectively. Survival rates of children in the high-risk group, with metastatic disease, aged <3 years, and with positive tumor cells in the cerebrospinal fluid(CSF) were very low. The 5-year OS rates were (54.8±5.3)%, (57.7±5.9)%, (41.6±8.7)%, and (53.0±7.3)%, respectively.Compared to others, the children with MB large-cell/anaplastic histology [5-year OS rate was (35.3±13.6)%] and MB group 3 subtype [3-year OS rate was (25.0±13.0)%] lived a miserable life.Meanwhile, the children in the stand-risk group, without metastatic disease, no large-cell/anaplastic histology, age older than 3 years, and with tumor cell negative in CSF, lived a better life. The 5-year OS rates were (87.5±3.5)%, (80.3±3.7)%, (70.6±5.5)%, (78.3±3.3)%, and (78.4±3.5)%, respectively, and all of them were over 70.0%. No WNT tumors progressed or relapsed, and 5- year OS rate was 100.0%. The survival status of SHH subgroup was inferior to that of group 4 subtype[(64.8±5.8)% vs.(83.5±3.8)%, χ²=5.417, P=0.015]. With COX analysis, age and tumor cells in CSF at the time of diagnosis were independent risk factors for OS and PFS of MB (PFS: Wald=8.485, P=0.004; Wald=11.702, P=0.001; OS: Wald=16.274, P=0.000; Wald=7.191, P=0.007). Conclusions Survival of children with MB more than 3 years old has been reached a perfectly high level.Age and tumor cells in CSF are independent risk factors for the OS and PFS. However, the prognosis of large-cell/anaplastic histology, malignancy cell positive in CSF, group 3 and children under 3 years old, is still poor, and intensive treatment is needed urgently for those patients.

Objective To investigate the early diagnosis and treatment of craniospinal irradiation(CSI)in-duced lung injury (RILI)in children with malignant brain tumors.Methods From January 2014 to January 2016,a total of 145 children with malignant brain tumors from Beijing Shijitan Hospital,Capital Medical University were enrolled in this study.All children received postoperative CSI.Ten children were diagnosed as RILI by high－resolution computed tomography (HRCT)scanning before the start of subsequent chemotherapy and 42 days after CSI.Oral Pred-nisone acetate tablets 0.5－1.0 mg/(kg·d)were given to treat RILI and compound Sulfamethoxazole to prevent sec-ondary lung inflammation.Antibiotic treatment and symptomatic support were given to 2 patients because of the com-bined infection.Then every 4 weeks HRCT was performed and the dosage of Prednisone was adjusted.Clinical charac-teristics and treatment effects were observed synthetically.Results Up to January 2018,the median follow－up time was 28 months (ranged from 26 to 48 months),only 10 patients suffered from RILI,and the morbidity was 6.9%.Eight of 10 patients had medulloblastoma,1 case with pineoblastoma,and 1 case with atypical teratoma/rhabdomyoid tumor. They were 6 boys and 4 girls,and the median age was 8 years old (ranged from 5 to 13 years old).The time points of diagnosis of lung damage were 39－52 days after the end of radiotherapy,and lesions were located in the dorsal or basal segments of lower lobe of unilateral or bilateral lung in HRCT scanning.No obvious respiratory symptoms or other dis-comfort was found except for frequent cough in 2 patients.Lung lesions were gradually reduced and disappeared within 2 to 8 months after treatment with Prednisone and compound Sulfamethoxazole.Two cases suffered severe infection be-fore or during the subsequent chemotherapy,and the condition was gradually improved after anti－infection treatment based on drug sensitivity test.Then subsequent chemotherapy underwent successfully.Conclusions RILI presents mild symptoms or asymptomatic.Routine lung imaging after radiotherapy is beneficial to the early diagnosis of lung damage, and early treatment with Prednisone and prophylaxis with compound Sulfamethoxazole has a good prognosis.

Objective To analyze the survival rate and adverse effect of therapy of childhood supratentorial primitive neuroectoderma (sPNET)patients in order to investigate a suitable therapy. Methods Between December 2012 and December 2014,18 children,aged from 0. 6 to 13. 6 years old,were treated with pediatric himtumor(HIT)-2000 protocol in Beijing Shijitan Hospital,Capital Medical University. All patients were performed tumor gross total re-section,and someone accepted irradiation therapy firstly. The adverse effect of radiotherapy and chemotherapy was ana-lyzed,and the 3 - year progression - free survival (PFS)rate and overall survival (OS)rate were calculated by using Kaplan - Meier method. Results Till September 2017,the mean follow - up time was 3. 0 years (0. 2 - 4. 8 years), and the survival rate was 72. 2％ (13 / 18 cases). Eleven cases(11 / 18 cases,61. 1％)were complete remission,but 7 cases (7 / 18 cases,38. 9％)relapsed during or after therapy. The 3 - year PFS and OS rates were (66. 7 ± 11. 1)％and (71. 8 ± 10. 7)％,respectively. Moreover,14 patients received craniospinal irradiation,and their 3 - year PFS and OS rates were (68. 8 ± 13. 3)％ and (85. 7 ± 9. 4)％,respectively,there was no significant difference between the overall rates(all P >0. 05). During the follow - up period,all patients were not involved radiation - reduced brain necro-sis,myelitis,and pancreatic injury. During the whole central radiotherapy,14 children had different degree of blood rou-tine abnormalities,mainly manifested in leukocytes and thrombocytopenia,and the blood routine was restored to normal after subcutaneous injection of granulocyte stimulating factor. The adverse reactions of the gastrointestinal tract were re-latively mild,mainly nausea and vomiting,and the improvement of the gastric mucosa and the protection of the gastric mucosa were all improved. The gastrointestinal tract adverse reactions caused by HIT - 2000 were mainly nausea,vomi-ting,abdominal pain,diarrhea,constipation,and so on. The incidence of hematological adverse reactions was high,up to 100％,of which 2 cases were cured by active anti infection and symptomatic treatment due to the lack of granulocytic and fever. Conclusion HIT - 2000 protocol is a feasible and efficient therapy method for sPNET of Chinese children patients,and the adverse effects are tolerable.