CLINICAL STUDY IN ACCELERATED HYPERFRACTIONATED IRRADIATION IN THE TREATMENT OF LOCAL ADVANCED NON-SMALL CELL LUNG CANCER

Objective To evaluate the effect of accelerated hyperfractionated irradiation (AHFJ) and conventional fractionated irradiation (CFI) for local advanced non- small cell lung cancer (NSCLC). Methods The patients of AI-IFJ group were irradiated to large-field target volume by a daily fraction of 2Gy, and small-field target volume by a daily fraction of 1Gy with more than 6h interval. The total dose of large-field target volume was SOGy/25Fx/SW and of small-field target volume was 7SGy/SOFx/5W. The patients in CFI group were irradiated by a daily fraction of 2Gy to the total dose of 66Gy/33Fx/6. 6W. After 3 months of radiotherapy, the tumor response rates of complete recovery (CR), partial recovery (PR), and no change (NC) and 1- and 2- year survival rate in the two groups were observed. Results The tumor response rates of CR,PR,NC in AHFI group and CFI group were 22.9%(8/35), 60.0%(21/35), 17.1%(6/35) and 11.4% (4/35), 51.4% (18/35), 37.2% (13/35) respectively (P>0. 05). All patients were followed up 2 years or more. The 1- and 2- year survival rates in AHFI group and CFI group were 62.9% (22/35), 31 .4% (11/35) and 42.9% (15/35) , 17.1% (6/35) respectively (P< 0.05). The incidences of esophagitis and pneumonitis in AHFI group and CFI group were 34.3% (12/35), 22. 9% (8/35) and 40.0% (14/35), 17.1% (6/35)(P>0. 05). Conclusion In comparison with CFI, AHFI may increase 1- and 2- year sur-vival rate after treatment of local advanced non-small cell lung cancer, while the radio-reactions, either early or late, did not increase significantly.

Accelerated partial breast irradiation:Current evidence and future developments

Whole breast irradiation after breast-conserving surgery for early breast cancer has become one of the standard treatment modes for breast cancer and yields the same effect as radical surgery.Accelerated partial breast irradiation(APBI)as a substitute for whole breast irradiation for patients with early breast cancer is a hot spot in clinical research.APBI is characterised by simple high-dose local irradiation of the tumour bed in a short time,thus improving convenience for patients and saving costs.The implementation methods of APBI mainly include brachytherapy,external beam radiation therapy,and intraoperative radiotherapy.This review provides an overview of the clinical effects and adverse reactions of the main technologies of APBI and discusses the prospects for the future development of APBI.

Feasibility and acute toxicity of 3-dimensional conformal external-beam accelerated partial-breast irradiation for early-stage breast cancer after breast-conserving surgery in Chinese female patients

Background A growing number of studies worldwide have advocated the replacement of whole-breast irradiation with accelerated partial breast irradiation using three-dimensional conformal external-beam radiation （APBI-3DCRr） for early-stage breast cancer. But APBI can be only used in selected population of patients with early-staged breast cancer. It is not replacing the whole breast radiotherapy. This study aimed to examine the feasibility and acute normal tissue toxicity of the APBI-3DCRT technique in Chinese female patients who generally have smaller breasts compared to their Western counterparts.Methods From May 2006 to December 2009, a total of 48 Chinese female patients （with early-stage breast cancer who met the inclusion criteria） received APBI-3DCRT after breast-conserving surgery at Sun Yat-sen University Cancer Center. The total dosage from APBI-3DCRT was 34 Gy, delivered in 3.4 Gy per fractions, twice per day at intervals of at least six hours. The radiation dose, volume of the target area and volume of irradiated normal tissues were calculated.Acute toxicity was evaluated according to the Common Toxicity Criteria （CTC） 3.0.Results Among the 48 patients, the planning target volume for evaluation （PTVE） was （90.42±9.26） cm3, the ipsilateral breast volume （IBV） was （421.74±28.53） cm3, and the ratio between the two was （20.74±5.86）%. Evaluation of the dosimetric characteristics of the PTVE revealed excellent dosimetric results in 14 patients and acceptable results in 34 patients. The dose delivered to the PTVE ranged from 93% to 110% of the prescribed dose. The average ratio of the volume of PTVE receiving 95% of the prescription dose （V95） was （99.26±0.37）%. The habituation index （HI） and the conformity index （CI） were 1.08±0.01 and 0.72±0.02, respectively, suggesting good homogeneity and conformity of the dose delivered to the target field. The radiation dose to normal tissues and organs was within the dose limitation.Subjects experienced mild acute toxicity. The main manifestations were breast edema in 22 patients, breast pain in 7,skin erythema in 25, general malaise in 22 and cytopenia in 8. No acute radiological cardiac or pulmonary injury was found.Conclusions The results of our short-term follow-up showed that it is feasible to perform APBI-3DCRT for early-stage breast cancer after breast-conserving surgery in Chinese female patients with smaller breasts. However, further studies are required to elucidate its efficacy and long-term side effects.

Development of High Power Irradiating Accelerator

The design of 10MeV/20kW high power irradiating accelerator is presented.The Backward-Traveling-Wave (BTW)accelerating structure is adopted.This structure combines the advantage of traveling-wave accelerator structure with low power reflection and high stability and standing-wave accelerator structure with high shunt impedance.The work frequency of this accelerator is 2856MHz.Designed by Code AccDesign which is coded by ourselves,the output electron beam with final energy 10MeV and peak current 300mA was reached.The length of the accelerating tube is 1.5m,and the power efficiency from microwave to electron beam is 66%.The temperature and stress distribution were simulated.And the frequency shift by microwave loss was calculated.