Objective To study the physical characteristics of the OPEN stereotactic body radiotherapy system for the clinical application. Methods The 0. 125cc ioniztion chamber, 160 mm polystyrene sphere model,Gafchromic EBT2 films and IBA film analysis software were used to evaluated the focus position tolerance,dose rate,repeatability,linear relation,penumbra and composite error of the OPEN stereotactic body gamma knife. We used the DTA method to verify the accuracy of dose distribution between the plans and measured value. Resualts The focus error was 0. 36 mm,max dose rate tolerance 3%,linear relation error 2%,repeatability error 0. 3%,composited error 2. 5 mm. There was 90% pass rate when the distance away from test point was less than 2 mm and the dose error was set less than 5 % . Conclusions Parts of the test resualts were similar to the head gamma knife national protocal of OPEN stereotatic body gamma knife. The deliver dose distribution can meet the clinic need.

OBJECTIVETo analyze the results of postoperative radiotherapy with electronic beam for patients with keloids in our hospital.

METHODSFrom September 2006 to May 2009, radiotherapy was given within 24 hours after operation in 53 keloid patients. With single vertical field irradiation, 6-12 Mev electronic beams of Linear Accelerator were selected for different incision depth in different sites. The field size was 1.0 cm (range: 0.5-2.0 cm) away from both incision ends and 1.25 cm (range: 0.75-2.50 cm) away from incision laterally. The radiation was given daily with median treatment course of 4 days (range: 3-21 days) at 3.5 Gy/Fx to a median total dose of 14 Gy (range: 8-20 Gy). SPSS 21. 0 was used for analysis.

RESULTSAll postoperative incisions healed in one stage, the median follow-up was 34 months (range: 18-63 months). The overall local control rate was 79.7%. For patients who received the dose of more than 14 Gy versus less than 14 Gy, the local control rate was 81.6%, 75.2%, respectively (P > 0.05). For male and female, the 3 year local recurrence rate were 45.3%, 9.9% respectively (P = 0.008). Multivariate analysis showed that the sex (male versus female) was an independent prognostic factor (P = 0.036).

CONCLUSIONSurgery combined with electronic beam irradiation is a rather effective way to treat keloids. The local control rate would have a better trend if the total dose was higher than 14 Gy. Sex is an independent prognostic factor.

Adolescent ; Adult ; Aged ; Female ; Follow-Up Studies ; Humans ; Keloid ; radiotherapy ; Male ; Middle Aged ; Postoperative Care ; Treatment Outcome ; Young Adult

Accurate delineation of clinical target volume (CTV) of nasopharyngeal carcinoma is of significance to prevent local recurrence and improve the survival rate of patients. When intensity-modulated radiotherapy (IMRT) was first introduced, CTV was delineated based on two-dimensional radiotherapy experience. The local recurrence-free survival is high, but the adverse reactions induced by radiotherapy are severe and the patients’ quality of life is poor. How to reduce CTV to alleviate acute and late radiotherapy-induced adverse reactions without deteriorating therapeutic effect has currently become a research hotspot. Despite the 2010 Chinese Nasopharyngeal Carcinoma IMRT Target and Dose Design Guideline Expert Consensus and the International Guideline for the Delineation of the CTV for Nasopharyngeal Carcinoma as references, the optimal individualized and standardized delineation of CTV remains controversial. This review summarizes the progress on the delineation of CTV of primary tumour of nasopharyngeal carcinoma, aiming to provide practical reference for clinicians.

High-risk neuroblastoma (NB) is highly aggressive and has poor prognosis. Treatment of NB mainly includes comprehensive therapies, of which radiotherapy serves as a part of consolidation therapy. For patients who receive complete resection of the primary lesion, usually an irradiation dose of 21-23.4 Gy is given; for patients with incomplete resection, further study focused on radiation dose is necessary. Recurrence is most commonly observed in the bone lesions involved at presentation. Currently, the principle of irradiation to the metastatic sites is to treat lesions where metaio-dobenzylguanidine (MIBG) uptake remains positive after induction chemotherapy, or those become negative uptake but still at high risk of recurrence. On the premise of lacking of MIBG imaging, positron emission tomography CT (PET-CT) may assist in screening for metastatic sites requiring irradiation. The late side effects of radiotherapy are mainly mild musculoskeletal abnormalities. No significant increase is observed in the incidence of second primary tumor during short-term follow-up.