FLASH radiotherapy is a hotspot in the domain of tumor radiotherapy in recent years, which delivers at ultra-high dose rate (usually > 100 Gy/s) in an ultra-short time (1?50 ms) to the target volume. The FLASH effect will be generated after the organism is treated with FLASH radiotherapy, which makes the tumor more easy to be killed and the normal tissue is protected after radiotherapy. Because of the differences in sensitivity to FLASH radiotherapy between tumor tissues and normal tissues, FLASH radiotherapy has a subversive advantage in the treatment of tumors. In this paper, several studies since 1959 on the effects of ultra-high dose rate rays and FLASH radiation on cells and organisms are summarized. As the predecessor of FLASH radiotherapy, ultra-high dose rate radiotherapy has laid a very important foundation for the development of FLASH radiotherapy.
Objective To observe the macular morphological changes of choroidal melanoma with coherence tomography (OCT) after plaque radiotherapy (PRT). Methods A total of 48 patients (48 eyes) with choroidal melanoma who underwent125I PRT were enrolled in this study. All the patients were examined documenting OCT to get the image of macula. The macula of all the patients was not involved. The median visual acuity was 0.4plusmn;0.2, which ranged from 0.02 to 1.0. There were 18 eyes (37.5%) with retinal detachment, 12 eyes (25.0%) with retinal pigment epithelium (RPE) changes, seven eyes (14.6%) with macular edema, epimacular membrane, detachment combined with edema, exudation and RPE changes, 11 eyes (22.9%) with normal macular structure. The median follow-up time was (10.4plusmn;5.9) months, which ranged from one to 24 months. The tumor control situation and visual acuity were observed in follow-up period. The same equipment and methods of OCT were used to return visit in follow-up period. The macular morphological changes at the final visit and its relationship with PRT and visual acuity were contrastively analyzed. Results All the patients had good control of tumor. The vision acuity improved in two eyes (4.2%), unchanged in 10 eyes (20.8%), and decreased in 36 eyes (75.0%). The differences of the visual acuity was statistically significant between before and after treatment (Z=-3.778,P＜0.05). There were 13 eyes (27.1%) with retinal detachment; nine eyes (18.8%) with RPE changes; 17 eyes (35.4%) with macular edema, detachment combined with edema, exudation and RPE changes; six eyes (12.5%) with proliferation, atrophy, detachment combined with edema, exudation and epimacular membrane;three eyes (6.3%) with normal macular structure. There were 15 patients (31.3%) with two or more abnormal macular morphology after PRT. Conclusions Retinal detachment, RPE changes, macular edema and exudation are common abnormal macular morphology after PRT. The incidence rate of abnormal macular morphology is increased. There are 31.3% patients with two or more abnormal macular morphology.
The incidence and mortality of lung cancer are increasing globally. With the spread of CT, more and more early-stage lung cancer can be detected and treated in a timely manner. As the main treatment of lung cancer, thoracoscopic anatomical segmentectomy in the treatment of non-small cell lung cancer is causing concern to the thoracic surgeons. Here, we will discuss the application of thoracoscopic anatomical segmentectomy in the treatment of early non-small cell lung cancer.
ObjectiveCompare the two-degrade collimator (MLC) angle selection's impact on plan quality and operational efficiency for volumetric intensity-modulated radiotherapy (VMAT) in the treatment planning system, and to explore the scheme for treatment plan optimization. MethodsTwenty patients with nasopharyngeal carcinoma underwent the treatment between March and December 2013 were randomly selected and planned for SIBVMAT treatment with different parameters set in the range of 0-60°with 15°interval for collimator angles. Planned dose distribution to the target volumes, organs at risk, and monitor units were compared. ResultsAs the MLC angle increased, target conformal index and homogeneity index had a trend to became deteriorated. The optimal plans were 0°and 15°, while 45°and 60°plans gave poor protection for the organ at risk compare to other angle plans and the monitor units were significantly increased. ConclusionChange the MLC angle had visible impact on treatment plans,there was a trend to deteriorate with the MLC angle increased, but small changes in MLC angle range can theoretically reduce the influence from leakage radiation on the human body.
ObjectiveTo compare the dosimetric differences among flattening filter free intensity modulated radiotherapy (3FIMRT), flattening filter free volumetric modulated arc therapy (3FVMAT), filter free intensity modulated radiotherapy (IMRT), and filter free volumetric modulated arc therapy (VMAT) for hyperthyroidism exophthalmus patients.MethodsComputed tomography (CT) scans of 29 patients, who were diagnosed with hyperthyroidism exophthalmus and treated with radiation therapy between September 2016 and September 2017, were selected for study. Four treatment plans with the same dose prescription and objective constrains were designed for each patient based on their images, consisting of IMRT, VMAT, 3FIMRT, and 3FVMAT. The target dosimetric distribution, normal tissue radiation dose, monitor units, and treatment time of each plan were evaluated.ResultsFour types of plans were all able to satisfy the clinical treatment requirements, and there were no significant differences in maximum dose, mean dose (Dmean), homogeneity index of the targets (P>0.05). For the parameters minimum dose, V50%, conformity index (CI), gradient index of the targets, statistically significant differences were observed among the four kinds of technologies (F=10.920, 35.860, 11.320, 17.790; P<0.05). The CI of IMRT and 3FIMRT were superior to those of VMAT and 3FVMAT, but there was no significant difference between IMRT and 3FIMRT. In terms of Lens Dmean and Brain Dmean, statistically significant differences were observed among the four kinds of technologies (F=5.054, 83.780; P<0.05). For Lens Dmean and Brain Dmean, 3FVMAT achieved better sparing effects when compared with the other three plans. The total monitor units and treatment time did not significantly differ between 3FVMAT and VMAT. The mean monitor units of 3FVMAT were 65.07% and 70.22% less than that of IMRT and 3FIMRT respectively. The mean treatment time of 3FVMAT were 48.1% and 35.24% less than that of IMRT and 3FIMRT respectively.Conclusion3FVMAT can bring more dosimetric advantages for hyperthyroidism exophthalmus radiation therapy when compared with IMRT, 3FIMRT, and VMAT.
ObjectiveTo investigate the effectiveness of internal mammary artery perforator (IMAP) propeller flap repair combined with radiotherapy for chest keloid in female patients.MethodsBetween January 2015 and December 2016, 15 female patients with chest keloids were treated, aged 28-75 years (mean, 45.2 years). The keloid disease duration was 1-28 years (median, 6 years). The causes of disease included secondary keloid caused by folliculitis in 7 cases, cardiac surgery in 4 cases, skin abrasion in 2 cases, mosquito bite in 1 case, and unknown etiology in 1 case. The size of keloid ranged from 5 cm×3 cm to 17 cm×6 cm. The IMAP propeller flaps were used to repair the defects after chest keloid excision. The size of flaps ranged from 7 cm×5 cm to 14 cm×8 cm. The donor sits were sutured directly. The routine radiotherapy was performed after operation.ResultsAll IMAP propeller flaps survived well, and the donor sites healed by first intention. All 15 patients were followed up 12-24 months (mean, 16 months). No telangiectasia or incision dehiscence occurred. No radiation-related carcinogenesis occurred during follow-up. The patients were satisfied with the breast shape and symmetry after operation. The symptoms of pain and itching relieved at keloid area in 13 cases (86.7%), with no obvious recurrence of keloid at the donor site and the primary site. Only 2 cases (13.3%) recurred and were treated with continuously conservative treatment.ConclusionIMAP propeller flap is an ideal reconstruction method for repairing the wounds after chest keloid excision in female patients, which can preserve the good breast shape. The IMAP propeller flap repair combined with early postoperative radiotherapy can effectively reduce the recurrence rate, and the effectiveness is satisfactory.
ObjectiveTo evaluate the value of postoperative radiotherapy (PORT) in patients with stage ⅢA-N2 non-small cell lung cancer who received complete resection and chemotherapy. MethodsPatients with stage ⅢA-N2 non-small cell lung cancer who received complete resection and chemotherapy were chosen from the SEER Research Plus Database [17 Registries, November 2012 Submission (2000-2019)]. The patients were divided into a PORT group and a non-PORT group according to whether the PORT was used. To balance baseline characteristics between non-PORT and PORT groups, R software was used to conduct a propensity score matching (PSM) with a ratio of 1 : 1 and a matching tolerance of 0.01. Both the Cox regression analysis and Kaplan-Meier survival analysis were conducted to evaluate the value of PORT in terms of overall survival (OS) and disease-specific survival (DSS). ResultsIn total, 2468 patients with stage ⅢA-N2 non-small cell lung cancer were enrolled, including 1078 males and 1390 females with a median age of 65 (58-71) years. There were 1336 patients in the PORT group, and 1132 patients in the non-PORT group. Cox regression analysis showed that PORT was not significantly associated with OS (multivariate analysis: HR=1.051, 95%CI 0.949-1.164, P=0.338) and DSS (multivariate analysis: HR=1.094, 95%CI 0.976-1.225, P=0.123). No statistical difference was found in the OS or DSS between non-PORT group and PORT group after PSM analysis (P＞0.05). ConclusionPORT does not have a survival benefit for patients with stage ⅢA-N2 non-small cell lung cancer who received complete resection and chemotherapy.
OBJECUIVE: To observe the therapeutic efficacy of gamma;-knife/lymphokine activated killing cells (LAK)in chorold malignant melanoma (CMM). METHODS:Five cases of CMM had keen treated by retrobulbar injection of LAK cells and gamma;-knife irradiation at multiple sites.Ophthalmologic,imageologic, fundus fluorescein angiographic and T lymphocyte subset examinations were done before and after treatment. Tile follow-up period of this series of cases was 6-24 months. RESUILS:Thc CMM of 4 in 5 treated cases became atrophic and withered up clinically after gamma;-kinfe/LAK therapy. Among the 4 cases,2 of them had been followed up for more than 2 years,and the other 2 for 20 and 14 months respectively. The tumor of the 5th patient wko was followed up for 6 months after treatment,reduced to 3/5 of the original size,and no blood flow was found within thee tumor mass under the clinical examination. CONCLUSION :The gamma;-knife/LAK therapy was effective in treating CMM in saving the affected eye from being enucleated. Chin J Ocul Fundus Dis,1997,13: 96- 98）
Objective To analyze the efficacy of and recurrence mode after adjuvant radiotherapy for lower thoracic esophageal squamous cell carcinoma (TESCC) patients after radical operation with anastomosis above aortic arch. Methods Sixty-three patients with lower TESCC who received adjuvant radiotherapy after R0 radical operation with anastomosis above aortic arch between February 2011 and February 2019 were retrospectively enrolled. The clinical tumor volume (CTV) included anastomotic stoma, and lymph node drainage area in mediastinum and upper abdomen. The survival status, recurrence and metastasis of tumors, and the influencing factors were analyzed. Results The 1-, 2-, and 3-year overall survival rates were 98.3%, 83.3%, and 63.7%, respectively. The median disease-free survival (DFS) was 33 months [95% confidence interval (23.2, 42.8) months], and the 1-, 2-, and 3-year DFS rates were 76.3%, 58.5%, and 41.7%, respectively. Patients with N0-1 had longer DFS than those with N2-3 (median: not reached vs. 15 months, P=0.045). The recurrence rate of anastomotic site was 7.9%. The recurrence rates of lymph nodes in supraclavicular region, upper middle mediastinum, and upper abdomen were 4.8%, 15.9%, and 1.6%, respectively. The distant metastasis rate was 17.5%. The incidence of grade 2-3 radiation pneumonitis, grade 3 anastomotic stenosis, and grade 3 tracheal fistula were 4.8%, 3.2%, and 1.6%, respectively. Conclusions N2-3 is a poor prognostic factor for such patients. Regional lymph node recurrence is mainly revealed in the middle and upper mediastinum. Whether the CTV should include anastomotic stoma and lymph node drainage area in lower mediastinum and upper abdomen is questionable.
Objective To summarize the current advancement of preoperative radiotherapy for rectal cancer. Methods Relevant literatures about current advancement of preoperative radiotherapy for rectal cancer published domesticly and abroad recently were collected and reviewed. Results The lower local recurrence rate and longer disease-free survival time were observed in preoperative radiotherapy， compared with postoperative radiotherapy for rectal cancer. The recurrence rate was higher in short-course radiotherapy， compared with conventionally radiotherapy for stageⅢrectal cancer， but there was no significant difference for stageⅡrectal cancer. The biology molecular such as p53， CEA， Cox-2， EGFR， and VEGF had shown to be radiosensitive. Conclusions The proposal of preoperative radiotherapy for rectal cancer， could be prone to conventionally radiotherapy. There are more screening targets for preoperative radiotherapy in extensive exploration of diverse radiosensitivity. Biology molecular， developed gene expression profiling， and gene chips for rectal cancer may contribute to the individualization treatment.