2017年 · 第37卷第05期

With the continuous development of radiotherapy technology, radiotherapy has become more and more important in the treatment of cervical cancer^[1,2]。 Many studies have been published on how to increase the target dose while reducing the exposure dose to the rectum, bladder and small intestine^[3,4]But the exposure dose of bone marrow in postoperative radiotherapy for cervical cancer is often neglected. Mell et al.^[5]Studies have shown that the exposure dose of bone marrow in radiotherapy is related to blood adverse reactions, and the increase of bone marrow exposure dose will lead to an increase in the incidence of acute myelosuppression. Therefore, how to effectively reduce the exposure dose of bone marrow without affecting the target area and other endangered organs has become an important issue that needs to be solved urgently. Based on the traditional intensity modulation program combined with non-coplanar technique, this study explores the dosimetric advantages of non-coplanar intensity modulation program applied to postoperative radiotherapy of cervical cancer.

Personal dose monitoring is an important part of occupational health monitoring of radiation workers, and accurate and reliable personal dose detection data is an important basis for the diagnosis of occupational radiation diseases. Regular assessment of personal dose monitoring ability of external exposure nationwide can play a role in standardizing personal monitoring of occupational external exposure, controlling the quality of personal monitoring of occupational external exposure, and improving the personal dose monitoring ability and level of radiation health technical institutions. The Institute of Radiation Protection and Nuclear Safety Medicine (referred to as the organizational unit) of the Chinese Center for Disease Control and Prevention organized the assessment of the dose monitoring ability of individuals exposed to foreign irradiation in 2016.

At present, intensity modulated radiation therapy (IMRT) has been widely developed in clinical practice, and its dose calculation model mainly uses superposition/convolution algorithm and pencil beam algorithm^[1]。 However, these calculation models are not accurate for dose calculation in field irradiation, cavity areas and heterogeneous tissues^[2]Therefore, dose verification must be performed prior to treatment. At present, the IMRT dose verification method mainly uses a phantom instead of the patient, and uses a two-dimensional planar detector matrix and a three-dimensional uniform phantom for measurement verification, and compares the measurement results with the results of the treatment planning system (TPS). The method can accurately evaluate the deviation of TPS dose algorithm in the phantom, and has certain reliability. However, for complex human bodies, it is impossible to measure the dose distribution of tumor target areas and endangered organs, which makes the practical significance of clinical dose verification greatly limited^[3]。 Monte Carlo (MC) algorithm simulates the transport and energy deposition process of each photon and electron in matter, and is the most accurate dose calculation method at present^[4]For the situation that conventional dose calculation methods, such as low density or non-uniformity of tissues, are difficult to ensure the calculation accuracy, which can more reflect its superiority.