Analysis of Key Points of Radiation Sources in Proton and Carbon Ion Radiotherapy Facilities in Shanghai / 中国医疗器械杂志

Compared with conventional high energy X-ray radiotherapy, proton/carbon ion has obvious advantages because of its Bragg peak dose distribution. However, proton heavy ion facility has complex structure, high energy and various radiation types due to various nuclear reaction processes, the radiation protection safety brought by the operation of facilities has gradually attracted attention. Taking the proton/carbon ion radiotherapy facility of Shanghai Proton and Heavy Ion Center as an example, the author mainly analyzed the operation principle of proton/carbon ion treatment facility, the basis of radiation protection, analysis of key radiation source points, etc., so as to provide theoretical support and experience for radiation protection.

Significance of PD-L1 expression in carbon-ion radiotherapy for uterine cervical adeno/adenosquamous carcinoma / 부인종양

OBJECTIVE: Programmed cell death-ligand 1 (PD-L1) is expressed in tumor cells and has been shown to predict clinical outcomes of several types of malignancies. The aim of this study was to investigate the effects of carbon-ion (C-ion) beam irradiation on PD-L1 expression in human uterine cervical adeno/adenosquamous carcinoma (UCAA) cells and clinical samples and to identify the prognostic factors for outcomes after C-ion radiotherapy (CIRT).METHODS: The effects of C-ion irradiation on PD-L1 expression in human UCAA and cervical squamous cell carcinoma cells were examined by flow cytometry. We examined PD-L1 expression in UCAA biopsy specimens from 33 patients before CIRT started (pre-CIRT) and after 12 Gy (relative biological effectiveness [RBE]) irradiation (post-12Gy-C) in 4 fractions of CIRT to investigate the correlation between PD-L1 status and clinical outcomes.RESULTS: The PD-L1 expression was upregulated by C-ion beam in a dose-dependent manner in HeLa and SiHa cells through phosphorylated Chk1. The overall frequencies of pre-CIRT and post-12Gy-C PD-L1 positivity were 45% (15/33) and 67% (22/33), respectively. The post-12Gy-C PD-L1 expression was significantly elevated compared to the pre-CIRT PD-L1 expression. There was no significant relationship between the pre-CIRT PD-L1 status and clinical outcomes, such as local control (LC), progression-free survival (PFS), and overall survival (OS). However, the post-12Gy-C PD-L1 expression had better correlation with PFS, but not with LC and OS.CONCLUSION: CIRT can induce PD-L1 expression in UCAA and we propose that PD-L1 expression after starting CIRT may become as a predictive prognostic marker in CIRT for UCAA.

Palliative external beam radiotherapy for advanced breast cancer patients with brain metastasis in the university college hospital Ibadan

Background: Brain metastasis is a dreaded complication that significantly reduces the quality of life in breast cancer patients. The treatment options are limited by the inability of many chemotherapeutic agents to cross the blood­brain barrier. Surgery also has a limited role, except in few selected patients with oligometastasis. Therefore, whole-brain radiotherapy (WBRT) remains the available option that gives a gratifying result. However, the benefit of this treatment modality in our resource-poor environment needs to be investigated. Materials and Methods: The data of breast cancer patients with brain metastasis who were treated with WBRT using cobalt-60 equipment between 2005 and 2009 were retrospectively collected from the departmental medical record unit. The information extracted included biodata, presenting symptoms, imaging modality for confirmation of brain metastasis, treatment records, performance status pre-WBRT and 4 weeks post-WBRT, and other supportive treatments. Results: A total of 52 female patients were reviewed between 2005 and 2009. The mean age of patients was 44.7 years. The common clinical features on presentation were headache, nausea, and visual impairment in 30.8% of patients with the WHO performance status score ranging between 2 and 4. Patients with more than three brain deposits accounted for 71.2% of all the brain metastases. The mean radiation dose used for WBRT was 30 Gy in 10 fractions, and total responses recorded were 86.5% with 53.8% complete improvement in patients' performance status 4 weeks after WBRT treatment. Conclusion: WBRT is an effective treatment modality for patients with brain metastasis in our resource-poor environment. However, improvement of patients' performance status declined with advancing age

Differential Proteomics Reveals the Potential Injury Mechanism Induced by Heavy Ion Radiation in Mice Ovaries / 生物医学与环境科学（英文）

In the present study, we used a proteomics approach based on a two-dimensional electrophoresis (2-DE) reference map to investigate protein expression in the ovarian tissues of pubertal Swiss-Webster mice subjected to carbon ion radiation (CIR). Among the identified proteins, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) is associated with the cell cycle[1] and that it influences proliferation in ovarian tissues. We analyzed the expression of UCH-L1 and the proliferation marker proliferation cell nuclear antigen (PCNA) following CIR using immunoblotting and immunofluorescence. The proteomics and biochemical results provide insight into the underlying mechanisms of CIR toxicity in ovarian tissues.

Protective effects of shikonin on brain injury induced by carbon ion beam irradiation in mice / 生物医学与环境科学（英文）

Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed protective effect on cerebral ischemic injury. Here we investigated the effects of shikonin on carbon ion beam induced radiation brain injury in mice. Pretreatment with shikonin significantly increased the SOD and CAT activities and the ratio of GSH/GSSG in mouse brain tissues compared with irradiated group (P<0.01), while obviously reduced the MDA and PCO contents and the ROS levels derived from of the brain mitochondria. The shikonin also noticeably improved the spatial memory deficits caused by carbon ion beam irradiation. All results demonstrated that shikonin could improve the irradiated brain injury which might resulted from its modulation effects on the oxidative stress induced by the 12C6+ ion beam.

The basic structure of heavy-ion tumor therapy facility / 中国医疗器械杂志

Heavy-ions have the similar characteristic of depth-dose distribution with protons, but exhibit enhanced physical and radiobiological benefits. With increasing development in technical and clinical research, more facilities are being installed in the world. At the same time, many critical techniques of heavy-ion therapy facility were optimized and completed. This paper classified and reviewed the basic structure of heavy-ion system equipments, especially the accelerator, gantry, nozzle , TPS.

Current status and prospectives of proton and heavier-ion beam therapy for tumor in the digestive system / 中华胃肠外科杂志

Particle radiotherapy using proton and heavier-ion beam was first proposed for clinical application by Robert Wilson in 1946. Compared to conventional photon radiation, proton and heavier-ion beam has significant physical advantage, and heavier-ion has unique biological characteristics. With the development of accelerator and radiation technique, it is being investigated for tumor treatment in many clinical centers. This article reviews the current status of clinical application of particle therapy using proton and heavier-ion beam in digestive system tumor.