Primary tracheal tumor is an uncommon disease in clinical oncology .It tends to be misdiag-nosed in very early stage ,as well as lack of standards for staging and treatment nowdays .The main strategy for the treatment of primary tracheal tumors is surgical comprehensive treatments .But as the huge development of modern radiotherapy technology the past a few years ,radiotherapy could play more and more important roles in the treat-ment of tracheal tumors.Meanwhile,the application of tracheal scaffold have provided the patients with tracheal tumors some new choices on the treatments .Yet,there are no guildline for the standard of the surgery ,the dose of the radiotherapy and the definition for the tumor target volumes .Here,we give a review on the latest process and research on the treatment of primary tracheal tumors .

Recently,the incidence rate of small cell lung cancer in elderly patients has been increasing . The mainly therapeutic approach of small cell lung cancer consists of radiotherapy ,chemotherapy and surgery ,with the treatment purpose of prolonging survival time and improving life quality .As the huge development of accurate radiotherapy technology occurred in the past a few years ,radiotherapy could play more and more important roles in the treatment with elderly patients .Yet,there is no unified standards of treatment for small cell lung cancer in eld-erly patients.Therefore,we give a review on the latest processes and research on the treatment of small cells lung cancer in elderly patients .

Objective To explore the radiosensitizatian of paclitaxel in human lung adenocareinoma cells. Methods A human lung adenocarcinoma cell line A973 was used in this study. The cytotoxicity of paclitaxel was investigated by using clonngenic assay to define the IC10,IC50 and IC90. The cells received either radiation(with different doses) alone or paclitaxel administrated before and after irradiation. Cell survival fractions were determined by clonogenic assay. Single hit multi-target model was used to determine survival curve parameters. Flow cytometry was performed to analyze the cell cycle distribution. Results The IC10, IC50 and IC90 of paclitaxel in A973 cells were 0.5,2.6 and 8.7 nmol/L,respectively. According to Do,Dq and SF2 value,the sensitivity enhancement ratio(SER) of IC10 was 0.97,1.01 and 2.00 when paclitaxel was added before irradiation, and 0.97,1.02 and 1.02 when after irradiation ; The SER of IC50 was 1.06,129.00 and 2.61 when paclitaxel was added before irradiation, and 0.94,220. O0 and 2.14 when after irradiation ;The SER of IC90 were 1.00,220. 00 and 2.09 when paclitaxel was added before irradiation,and 0.98,220.00 and 2.09 when after irradiation. The IC10 of paclitaxei failed to increase G2+M arrest of A973 cells.The maximal G2+M accumulation was reached at 2 h and 18 h after IC50 and IC90 of paclitaxel treatment,respectively. Conclusions Paclitaxel is able to enhance the radiation sensitivity of A973 cells. Sequence of treatment is not associated with radiosensitivity. Moderate and high dose of paclitaxel combined with low-dose radiation can produce the best effect of radiosensitiation.

ObjectiveTo analyze the transitional shifts between with different sets of cone-beam computed tomography (CBCT) and the planning CT for liver cancer patients,and calculate the margins from clinical target volume (CTV) to the planning target volume (PTV)with and without image guided radiotherapy (IGRT).MethodsFive liver cancer patients received radiotherapy after transcatheter arterial chemoembolization (TACE).The first CBCT images (CBCT1) were obtained with Elekta CBCT plus active breathing control (ABC) system before treatment.The second CBCT images (CBCT2 ) were obtained after correcting the set-up errors and the third CBCT images ( CBCT3 ) were obtained after treatment.The CBCT images were registered and matched with the planning CT images using lipiodol as a direct surrogate for target localization.The PTV margins were calculated by comparing the shift between planning CT and CBCT according to formula M =2.5 ( Σ doctor2 + Σ set-up2 + Σ transter2 )1/2.Paired t-test was used to compare the differences between the results from CBCT1,CBCT2 and CBCT3. Results The average transition shifts in the left-right ( LR),superior-inferior (SI) and anterior-posterior (AP) directions were 0.254,-0.612,0.314 cm between planning CT and CBCT1 ;were 0.020,0.014,-0.064 cm between planning CT and CBCT2 ;and they were -0.004,0.042,-0.040 cm between planning CT and CBCT3.The PTV margins were LR 0.96 cm,SI 0.96 cm and AP 0.83 cm without IGRT,and LR 0.67 cm,SI 0.68 cm and AP 0.58 cm with IGRT.ConclusionsThe PTV margins can be reduced by 3 mm with IGRT for liver cancer using lipiodol as a direct surrogate for target localization.

Small cell lung cancer (SCLC) has the biological characteristics of high recurrence and metastasis. The brain is the common site of SCLC extrapulmonary metastasis. Prophylactic cranial irradiation (PCI) can effectively reduce the incidence of brain metastasis and prolong the overall survival of patients with limited SCLC. Nevertheless, nearly one third of patients develop brain metastases after PCI. This article reviews the risk factors of brain metastasis after PCI, aiming to determine which subgroup of patients with limited SCLC can benefit from PCI and provide reference for the clinical application of PCI.