2015年 · 第24卷第03期

The surface dose ratio of high energy photon beam is low, this phenomenon is called dose build-up, and the effect of megavolt photon beam build-up is more remarkable^[1]The skin surface dose is only about 25% of the maximum dose. Clinically, in order to treat tumors close to the surface of the skin, it is necessary to add Bolus to the skin surface to increase the skin dose. Surface dose and D_maxThe depth depends on the energy of photon line, the size of irradiation field, the pitch of source skin and the incident angle^[2,3,4]。 Accurate measurement of surface dose can provide valuable evidence for evaluating skin dose and preventing adverse reactions in clinical radiotherapy^[5,6]。 During the clinical treatment of patients, due to the irregular change of body surface contour, Bolus cannot be fully applied to the body surface. In order to determine the acceptable criteria for treatment, the effect of 1 cm thick Bolus on surface dose and depth was investigated when the gap between skin and skin was 0~2 cm.

Radiotherapy, as one of the three main anti-tumor therapies, plays an important role in the treatment of head and neck tumors. However, it is often difficult to completely avoid the surrounding normal tissues in the irradiated field, which easily leads to radiation-induced parotid gland injury, which is manifested by changes in the quality and quantity of saliva of patients, with different degrees of dry mouth, dental caries and malnutrition, which seriously affects the quality of life of patients. At the same time, the volume and position of parotid gland also changed during radiotherapy, resulting in the inconsistency between the actual volume and the planned evaluation, which caused certain difficulties in accurately evaluating the volume of parotid gland. This article reviews the structural, functional and positional changes of parotid gland caused by head and neck radiotherapy.

The standard surgical treatment of early breast cancer is modified radical mastectomy or breast-sparing surgery, which is often combined with radiotherapy, chemotherapy and endocrine therapy. Some patients after modified radical resection need postoperative adjuvant radiotherapy, such as postoperative pathological T₃— T₄Stage, axillary lymph node metastasis ≥4, etc.; Breast-conserving treatment has become the first choice for early breast cancer, and most patients need adjuvant radiotherapy and chemotherapy after surgery^[1]。 Two items in recent yearsaThe results showed that LC rate, specific survival rate and OS rate were significantly improved by radiotherapy after breast conservation operation^[2,3,4]。 Radiotherapy after breast-conserving surgery significantly increased the rate of LC and OS, the 10-year LR rate decreased from 35% to 19. 3%, and the 15-year breast cancer-related deaths decreased from 25. 2% to 21.4%^[3]。 Patients after breast-conserving surgery need adjuvant radiotherapy, and most patients also need adjuvant chemotherapy and other systemic therapy after surgery. However, the choice of radiotherapy and chemotherapy sequence or other factors may lead to the delay of radiotherapy or chemotherapy start time. So far, there are few prospective studies on the prognostic effects of delayed radiotherapy after breast-conserving surgery, but most of them are retrospective studies. In this paper, the effects of delayed radiotherapy on prognosis during postoperative radiotherapy alone, sequential postoperative therapy and concurrent postoperative chemoradiotherapy were analyzed by literature review, and the optimal timing of radiotherapy after breast-conserving surgery for breast cancer was discussed.

On March 26-28, 2015, the 7th National Nasopharyngeal Cancer Academic Conference, jointly sponsored by Nasopharyngeal Cancer Professional Committee of China Anti-Cancer Association and Radiation Oncology Therapy Branch of Chinese Medical Association, undertaken by Zhejiang Cancer Hospital, Nasopharyngeal Cancer Professional Committee of Zhejiang Anti-Cancer Association and Oncology Journal, and co-organized by Zhejiang Key Laboratory of Radiation Oncology and Zhejiang Cancer Diagnosis and Treatment Quality Control Center, was successfully held in Hangzhou. More than 500 experts and colleagues from Europe, America, Hong Kong, Taiwan and various provinces and cities in China engaged in clinical diagnosis and treatment, basic research and epidemiology of nasopharyngeal carcinoma attended the conference, and received more than 200 submissions and reports from the conference. With the theme of "Individual, Precision, Synergy and Development", the conference deeply discussed key topics such as clinical staging of nasopharyngeal carcinoma, individualized diagnosis and treatment decision-making, realization of precise treatment, clinical research collaboration and related basic research, etc. It is one of the most important academic conferences to guide the multi-center clinical research of nasopharyngeal carcinoma in China. Building an academic platform for nasopharyngeal carcinoma experts at home and abroad to enlighten thinking, exchange experiences, share information, strengthen cooperation and improve together will play a positive role in promoting the development of nasopharyngeal carcinoma in China.