Chemotherapy, molecular targeted therapy, and hormonal therapy are essential components of medical oncology. Al-though cancer patients significantly benefit from the emergence of various new anticancer drugs, none of these treatments can directly address drug resistance. Radiation therapy is one of the three conventional cancer treatment methods. Nearly two-thirds of cancer pa-tients accept radiation therapy during treatment. However, radiation resistance is a significant barrier affecting the therapeutic effect of this procedure. Epithelial–mesenchymal transition (EMT) is a biologic process that enables a polarized epithelial cell to undergo multi-ple biochemical changes. These changes enable the cell to assume the functions of a mesenchymal cell phenotype. These functions have been extensively studied and are related to embryogenesis, tumor invasiveness, and metastasis. In recent years, increasing evidence sug-gests that EMT is closely linked with tumor treatment resistance. The study of the relation between EMT and tumor treatment resistance is expected to contribute to the prevention of drug resistance and radiation resistance and thus improve treatment efficacy to provide benefit to cancer patients. This article explores this issue.

Small cell lung cancer ( SCLC ) is one common type of lung cancer in China. No remarkable progress has been made in systemic therapy for SCLC since the 90’ s. However, there are some advances in radiotherapy ( RT) for SCLC, which make it possible to improve treatment outcomes of SCLC. Those advances are mainly made in thoracic RT and prophylactic cranial irradiation for extensive?stage SCLC, radiation dose and technology of thoracic RT for limited?stage SCLC, and significance of prophylactic cranial irradiation for early?stage SCLC. The paper reviews the research advances in the East and West to provide some help and references for readers.

As a newly identified T helper cell subset, Th9 plays an important role in anti-tumor immunity. Th9 can be differentiated from CD4+T cells that have been induced by TGF-beta and IL-4. In addition, other CD4+T helper cell subsets can be developed to Th9 cell in particular situations, thereby showing its plasticity. Results of animal experiments have indicated that Th9 inhibits tumor growth and plays a significant role in anti-tumor immunity by secreting related cytokines such as IL-9. A few cytokines and molecules can regu-late the differentiation and development of Th9 cells in different signaling pathways. This review will focus on the production, anti-tu-mor immunity, related mechanism, and signaling pathways of Th9 cells, thereby providing a new field of vision and idea for anti-tumor therapy in the future.

Radiation?induced heart disease ( RIHD) is a common type of radiation?induced damages in chest radiotherapy. There are no obvious short?term symptoms in patients with RIHD. However, RIHD causes irreversible permanent damages to the heart over time, which undermines the quality of life. Patients with severe RIHD even have a risk of death from myocardial infarction caused by coronary atherosclerosis. This paper summarizes the research advances in epidemiology, diagnosis, mechanisms of radiation?induced injury in various parts of the heart, radiotherapy techniques, and treatment. Reduction in radiation range and dose, early diagnosis, and early treatment are recommended for patients to reduce heart injury and improve the quality of life.

As a DNA damage sensor,poly (ADP-ribose) polymerase (PARP) is involved in a wide variety of cellular activities,such as DNA damage repair.PARP inhibitors regulate a series of cellular activities by inhibiting PARP function,which have become a focus of current research.Recently,several in vivo and in vitro studies showed that PARP inhibitors combined with radiotherapy effectively enhanced the efficacy of radiotherapy.This paper reviews the research advances in the mechanisms of action of PARP inhibitors and their combination with radiotherapy.

Although it has been frequently used to treat thoraxic tumors,radiation induced lung injury (RILI) is the major factor of dose limitation in thoracic radiotherapy.Amount of endogenous and exogenous reactive oxygen / nitrogen species (ROS/RNOS) could be generated in the radiated organisms and further cause molecular damage of DNA,protein and membrane lipids,which results in celluar structure damage,dysfunction and RILI.In addition,a series of cytokines could also induce chronic oxidative stresses that contribute to increases in cell membrane permeability,tissue edema and extracellular matrix proteins accumulation and even further result in pulmonary fibrosis.Oxidative stress theory offers new clues and strategies for further understanding the mechanism of RILI,and some anti-oxidative stress drugs may have potential clincial application in RILI treatment.

Radiotherapy is important for cancer treatment. However, some patients still experience relapse and exhibit radiation resistance. Mammalian target of rapamycin (mTOR) is the main effector molecule in PI3K/AKT signaling. This molecule is found in two structurally and functionally distinct multi-protein complexes known as the mTOR complex 1 and mTOR complex 2. The mTOR signaling pathway controls the growth, proliferation, survival, and apoptosis of cancer cells. This pathway is closely related to tumori-genesis and treatment response, and is used in sensitizing radiotherapy. mTOR inhibitors regulate radio-sensitization through multiple mechanisms, including cell cycle alterations, DNA repair modulation, and tumor hypoxia reduction. Preclinical studies showed that mTOR inhibitors with tolerable toxicity may be used as an effective modality to overcome radio-resistant tumors. Responses to mTOR inhibitors vary depending on the cell lines. Molecular markers can be used to select suitable patients. Further studies are needed to com-pletely understand the use of mTOR inhibitors in radio-sensitization.

Objective To evaluate the influence of respiration on the radiation dose distribution within target volume in radiotherapy with film dosimetry. Methods Radiation of 50 MU was delivered by a square, round, ellipse, dumb bell, or female shaped filed to the films within a moving or motionless Respiration Motion Phantom respectively, the dose distributions for the two motion status were measured and compared. In order to further verify the impact of respiration, a plank phantom was used on different shifting value: 0, 0.5, 1.0, 1.5 and 2.0 cm, respectively. A square, round, or eUipse-shaped filed was used for irradiation and the distributions in different status were measured and compared with film dosimetry. Iso-dose line comparison, NAT(Normalized Agreement Tests) and γ comparison were used for the comparison of dose distributions. Fs can be an index to reflect the variability of the areas that surrounded by iso-dose lines. (FS90, FS50, FS25 delegates the ratio of the areas that surrounded by 90 %,50 %,25 % iso-dose hne in different situation respectively). Results (1) Compared with motionless situation, the FS90 in horizontal movement situation became small and the FS25 became large. As the displacement became larger, the FS90 became larger and the FS25 became smaller. FS in vertical movement situation, square and dumb bell fields changed while the others didn't have a change. (2)γ and NAT comparison: In the horizontal movement situation, compared with the static phantom, Pγ < 60 % and PNAT < 75 %. Under vertical movement situation, Pγ were less than 85 % for the square, round, dumb bell and female shaped fileds. In the plank phantom verification, Pγ and PNAT became smaller as the movement became larger. Conclusions The respiration can impact on the dose distribution within the target volume in radiotherapy, leading to a smaller area of higher dose level and an expanded area of lower dose level. The influence will become more significant with larger movement of the target.

The current challenge from radiotherapy of early breast cancer has been to minimize the morbidity caused by this treatment without losing efficacy.Conventional two-dimensional radiotherapy breast plans can produce substantial dose inhomogeneities.Intensity-modulated radiotherapy(IMRT) can be used to improve the dose homogeneity in an irradiated volume.And to some extent,IMRT can reduce radiation doses to adjacent normal tissues including the contralateral breast,heart and lung,and improve the cosmetic outcome.