Brachytherapy was the earliest technique of radiotherapy for the treatment of cancer and still is an important part of modern radiation oncology.It has been widely used as one of the modalities for gynecological cancer as well as head and neck cancer.In recent years,radioactive seed implantation has been proved to be one of the standard treatments for early stage prostate cancer,and brachytherapy alone is emerging as the major treatment for early stage breast cancer after lumpectomy.This article reviewed the current status of brachytherapy in clinical application as reported during the 2005' annual ASTRO meeting and its prospected for future development.

Objective:To investigate the influencing factors of quality of life (QOL) in rectal cancer patients with long-term sur-vival (LTS). Methods:A total of 107 patients with stageⅡandⅢrectal cancers were enrolled in this study. Questionnaires were used to determine the clinical factors affecting the QOL of rectal cancer patients with LTS. Results:Physical, emotional, social, and sexual functions were better in patients without colostomy than in those who underwent surgery. However, bowel function was worse in pa-tients who did not undergo surgery (P<0.05). A decrease in social function and QOL was observed in patients who underwent more treatments, and fatigue and insomnia symptoms were more obvious (P<0.05). Logistic regression analysis indicated that treatment was an independent predictor of QOL and negatively correlated with QOL. Conclusion:Treatment is an independent predictor of QOL in patients with stageⅡandⅢrectal cancers, and is negatively correlated with QOL. Surgery is a major factor that affects patient QOL. Improvement of medical technology and reasonable chemoradiotherapy should ameliorate the QOL of patients with LTS.

Objective To evaluate the long term local control and survival of nasopharyngeal carcinoma using radiotherapy combined with different chemotherapy regimens. Methods From July 1987 to October 1989, 300 patients pathologically confirmed nasopharyngeal carcinoma were randomized into three groups: radiotherapy alone (114 patients), neoadjuvant chemotherapy plus radiotherapy (93) and concurrent chemotherapy and radiotherapy (93). The primary tumor received a total dose of 70 Gy with 2?Gy per day. Patients who had cervical lymph node metastasis received 65～70?Gy to the neck whereas patients who did not have cervical lymph node metastasis received a prophylactic radiation of 50?Gy. The regimen of neoadjuvant chemotherapy consisted of 5 Fu (1?000?mg, 3 times per week) and Cisplatin (100?mg,once a week) alternatively for 4 weeks. Concurrent chemotherapy consisted of Cisplatin (20?mg, twice a week) and 5 Fu (500?mg, twice a week) alternatively to 6 weeks. Results The overall 5 year survival rate (OS), disease free survival rate (DFS), distant metastasis free rate(DMF)and local regional free rate (LRF) were 57.1%, 52.9%, 61.0% and 83.3%, respectively. For all patients, there was not a significant difference in the 5 year OS, DFS, DMF, LRF (P= 0.23, 0.65, 0.54, 0.83) and toxicity between these three groups. Cox regression analysis showed that only N stage was a prognostic factor, while treatment modalities was not. Conclusions Radiotherapy combined with neoadjuvant chemotherapy or concurrent chemotherapy did not significantly improve the survival rate and local control rate as compared to conventional radiotherapy. Therefore, radiotherapy plus chemotherapy, and chemotherapy regimens need to be further studied.

Objective To analyze the treatment results of intracavitary hyperfractionated brachytherapy for nasopharyngeal carcinoma and to determine the optimal dose of external radiation. Methods From February 1996 to June 1998, 128 patients with T1 2 nasopharyngeal carcinoma were treated with external radiotherapy followed by intracavitary brachytherapy. The majority of them had residual tumor less than 10 mm after external radiotherapy. The external radiation doses were divided into 3 groups: 56 Gy, 60 Gy and 66 Gy. Brachytherapy was delivered with 2.5 3.0 Gy per fraction, 2 fractions a day with an interval of 6 hours. The total doses ranged from 12 to 24 Gy with a median of 18 Gy. Results The disease free survival rates at 3 and 4 years for all patients were 84.2% and 74.9%, respectively. The corresponding local relapse free survival rates were 97.1% and 92.7%, respectively. The 3 year disease free survival rates and local relapse free survival rates were 83.6% and 100% for 56 Gy group, 88.4% and 90.9% for 60 Gy group, and 84.6% and 93.3% for 66 Gy group, respectively,all with differences in significant. Radiation complications were rare. Conclusions We suggest that patients with residual tumor less than 10 mm after external radiotherapy should receive intracavitary brachytherapy as a boost. The dose of external radiotherapy for T1 2 stage NPC can be decreased to 56 Gy.

Objective To study the results of external beam radiotherapy plus 192 Ir hyperfractionated high dose rate interstitial brachytherapy (HHDR-IBT) for cancer of the oral cavity and oropharynx. Methods Fourty-eight patients with cancer of the oral cavity and oropharynx were treated by external beam radiotherapy (T 1,T 2 30～50 Gy,T 3,T 4 50～60 Gy) followed by 192 Ir HHDR-IBT delivering 15～35 Gy (30～35 Gy for T 1,T 2 and 15～30 Gy for T 3,T 4 in 250～350 cGy per fraction,two fractions per day). Over 3～5 days. Results The complete response rates at 3 months were T 1100% (5/5),T 2 85%(23/27),T 3 46%(6/13),T 4 0%(0/3) and the partial reponse rates:T 2 15% (4/27), T 3 54%(7/13), T 4 100%(3/3). The 3-year survival and disease-free survival rates were 79.4% and 55.8%,respectively.Multivariate analysis showed that TNM stage and pathalogic type were prognostic factors.Conclusions Carcinoma of the oral cavity and oropharynx treated with external beam radiotherapy combined with 192 Ir hyperfractionated high dose rate interstitial brachytherapy ia able to give a good local control for T 1,T 2 lesions with good functional preservation. For T 3,T 4 lesions,this method is able to offer a high palliation.

Objective To scrutinize the positioning accuracy and reproducibility of the cone-beam computed tomography system in combination with the six-degree couch table (Hexapod Robot Treatment Table, HRTT). Methods The mechanical stability of the X-ray volume imaging (XVI) system was tested,in terms of the reproducibility. And the influence of the moveable parts, including the KV panel and the source arm, on the accuracy of the XVI image registration was analyzed. The accuracy between the bone and grey value registration was compared using a head-and-neck phantom. The accuracy of the HRTT for translational, rotational, and a combination of translational and rotational corrections was investigated in consecutive measurements. Results The performance of XVI system itself was stable with translational and rotational error of below 0. 4 mm and below 0. 3°, respectively. The mean position accuracy of the XVI system in combination with the HRTT summarized over all measurements was below 0. 6 mm and below 0. 4° for translational and rotational corrections, respectively. The grey value match was more accurate than the bone match. Conclusions The XVI image acquisition and registration procedure were highly reproducible.Both translational and rotational positioning errors can be corrected very precisely with the HRTT. The HRTT is therefore well suited to complement CBCT to take full advantage of position correction in six degrees of freedom for image guided radiotherapy.

Objective To study the set-up errors by CBCT in IMRT with two different immobilization techniques for thoracic and abdominal tumors.Methods Sixty patients with thoracic and abdominal tumor were included in this study and separated into study group and the control group.The study group were immobilized with carbon fiber holder,vacuum bag and thermoplastic mask.The control group were immobilized with carbon fiber holder and thermoplastic mask.CBCT scan and auto-match online were regularly performed before the treatment.The setup of left-right(x),superior-inferior(y),anterior-posterior (z) were received.The value of the Mptv was calculated,meanwhile.The grouped t-test of was carried out between these two methods.Results The shift errors in x-,y-,z-dimension of the study group were (0.32 ± 2.58) mm,(-0.40 ± 3.89) mm,(-0.75 ± 2.43) mm.The Mrrv were 5.60 mm,6.08 mm,6.32 mm.The translation set-up errors in x-,y-,z-dimension of the control group were(0.62 ±3.60),(2.44 ± 4.93),(0.66 ±2.85) mm,respectively.The MPrv were 8.07,10.63,6.90 mm,respectively.The t-test value were t =-0.78,-5.11,-4.22,P =0.440,0.000,0.000,respectively.Conclusions The immobilization techniques with carbon fiber holder,vacuum bag and thermoplastic mask would be better than the techniques without the vacuum bag in reducing the setup errors.

ObjectiveTo evaluate the outcomes and toxicities of elderly nasopharyngeal carcinoma (NPC) treated with conventional radiotherapy alone.MethodsFrom January 1995 to December 1998,95 newly diagnosed nasopharyngeai carcinoma with age ≥65 years treated in our hospital.The clinical data were analyzed retrospectively.Kaplan-Meier method was used for analysis of local-regional control survival and distant metastasis-free survival. The Logrank test was used for univariate prognostic analysis and Cox regression was used for multivariable prognostic analysis.ResultsThe follow-up rate was 98％.The 3-,5- and 8-year local-regional control (LRC) and distant metastasis-free survival (DMFS) rates were 89％,87％,84％ and 85％,79％,79％,respectively. The most common acute toxicities were grade1-2 leukopenia (36％),skin reaction (64％) and mucositis (66％).The most frequent late toxicities were hearing impairment (8％),trismus ( 10％ ) and radiation-induced cranial neuropathy (5％).In univariate analysis,interruption of radiotherapy ( χ2 =7.45,P =0.006 ) and regional neck lymph nodes response (χ2 =4.17,P=0.041 ) was the prognostic factors for LRC,T stage (χ2 =4.16,P=0.032),N stage ( χ2 =4.66,P =0.031 ) and interruption of radiotherapy ( χ2 =9.42,P =0.002 ) was the prognostic factors for DMFS. In multivariable analysis,interruption of radiotherapy and the regional neck lymph nodes response were the prognostic factors for LRC (χ2=6.19,P=0.013 and χ2=12.16,P=0.002;respectively),N stage and radiotherapy interruption were prognostic factors for DMFS.(χ2=15.06,P =0.000 and χ2 =21.62,P =0.000 ; respectively ).ConclusionsConventional radiotherapy alone for elder NPC can produce satisfactory results with acceptable treatment-relative toxicities.Our experience showed that the early N stage,without radiotherapy interruption and good regional lymph nodes response had a good longterm prognosis.

ObjectiveTo investigate whether the T1-weighted dynamic contrast-enhanced perfusion magnetic resonance imaging (DCEPMRI) technique can help to delineate the clinical target volume of brain glioma patients.MethodsThe DCE T1-weighted images from 28 glioma patients were collected after GdDTPA was injected.After the acquired images were processed and analyzed using modified Tofts-Kermode'two compartment analysis model and de-convolution method,the value and its pseudo mapping of quantitative parameter Ktrans related to microvascular permeability were obtained.The tumor size in the largest diameter slice measured both in routine enhanced MRI and Ktrans mapping of T1-weighted DCEPMRI were compared.ResultsThe vascular permeability and tumor infiltration was lower in low grade glioma,the difference of the tumor size between T1-weighted DCEPMRI and routine enhanced MRI reached 0.2％ -0.3％ there was significant difference of tumor size between T1 -weighted DCEPMRI and routine enhanced MRI ( grade Ⅰ and Ⅱ grade with 2.93 cm2∶2.46 cm2(t=6.90,P=0.000) and 4.18 cm2∶3.21 cm2(t=10.22,P=0.000) ).While in high grade glioma,the vascular permeability and the tumor infiltration were higher,the difference of the tumor size between T1-weighted DCEPMRI and routine enhanced MRI reached 25％ - 26％( the size of grade Ⅲ and Ⅳ were 6.46 cm2 vs 5.48 cm2 ( t =10.83,P =0.000) and 8.26 cm2 vs 6.52 cm2(t =18.53,P =0.000) ).ConclusionsThe pseudo mapping of quantitative parameter Ktrans related to microvascular permeability acquired by T1-weighted DCEPMRI reflect the infiltrating circumscription in glioma,T1-weighted DCEPMRI can provide more information in delineation the clinical target volume,and it can be used as a new method for tumor volume evaluation.

Objective To study the outcomes of nasopharyngeal carcinoma treated by late-course 3-dimentional conformal radiotherapy(3DCRT). Methods 37 primary nasopharyngeal carcinomas were involved into the CRT group. A total dose of 70 Gy to 74 Gy was delivered by using the conventional method (36 Gy) and late-course 3DCRT technique (34 ~ 38 Gy). This group was matched with a same number of patients who were treated with conventional method alone (Routing group). The treatment results and acute toxicity between the two groups were analyzed. Results The complete response (CR) rate of primary tumor was achieved 100 % in CRT group and 86 % in routing group, respectively. The CRT group had severe mucositis and peripheral neuropathy, but the difference was not statistically significant. There was no difference in the overall survival between the two groups. Conclusion Late-course 3DCRT is an effective method in the treatment of primary nasopharyngeal carcinoma.