Study of the feasibility of needle path optimization in 3D brachytherapy for cervical cancer / 中华放射肿瘤学杂志

Objective To compare the dosimetric differences between free-hand method and virtually optimized method for implanting needles in intracavitary and interstitial combined brachytherapy (IC/IS BT) of cervical cancer,and to explore the improvement space of the existing interstitial brahcytherapy plan.Methods High-dose-rate cervical cancer IC/IS BT plans (short for Treatment-Plan) of 18 cases were retrospectively analyzed.For each treatment plan,Nucletron Oncentra 3D brachytherapy planning system was utilized to redesign the virtually optimized insertion method IC/IS BT plan (short for Optimized-Plan).Dose volume histogram was adopted to evaluate the dose distribution in high-risk clinical target areas and exposure dose to organ at risk (OAR).The plan execution efficiency between two plans was also assessed.Results Comparing these two plans,the differences in conformity and uniformity of dose distribution of the target area were statistically significant (P=0.000,0.008).The differences of D0.01 cm3,D1 cm3,D2 cm3 and D5 cm3 in bladder,rectum,sigmoid and small bowel were all statistically significant (all P＜0.05).Optimized-Plan could reduce the D2 cm3 of bladder,rectum,sigmoid and small bowel by 60.41,36.43,27.53 and 12.43 cGy,respectively.The execution time for the Treatment-Plan and Optimized-Plan were (857.92±243.39) s and (804.53±239.13) s with statistical significance (P＜0.001).Conclusions Compared with the free-hand method,virtually optimized method yields more conformable coverage of the target area and more uniform dose distribution.At the same time,the doses of each OAR are reduced to different degrees and the execution time of the plan is also shortened.

Clinical effectiveness analysis on biliary stent combined with 125I seed implantation in the treatment of malignant obstructive jaundice / 中国现代普通外科进展

Objective:To investigate the clinical effectiveness analysis on biliary stent combined with 125I seed implantation in the treatment of malignant obstructive jaundice.Methods:98malignant obstructive jaundice patients undergoing percutaneous transhepatic biliary drainage requirement of biliary stent were divided into combined group(n=53) and simple group(n=45).Patients in combined group were taken biliary stent combined with 125I seed implantation,while in simple group were only taken biliary stent.All patients were followed up for 4 to 28 months.The changes of total bilirubin were recorded before percutaneous bile duct drainage,7 d,30 d and 90 d after biliary stent implantation.The recurrences of biliary obstruction of the two groups were recorded.The changes of T lymphocyte subsets in peripheral blood were detected before percutaneous bile duct drainage and after biliary stent implantation 7 d.The survival times of the two groups were compared.Results:All patients were successfully completed biliary stent implantation,surgical success rate was 100％.The total bilirubin levels of patients in combined group 30 d and 90 d after stent implantation were significantly lower than the simple group,the differences were statistically significant (P＜0.05).After surgery 7 d,the CD4 level and CD4/CD8 ratio in combined group were increased compared with before surgery,while in the simple group were declined,the differences were statistically significant (P＜0.05).Compared with the simple group,the CD4 level and CD4/CD8 ratio in combined group after surgery 7d were significantly increased (P＜0.05).2 cases (3.8％) of patients were recurrence of biliary obstruction,which were lower than 17 cases (37.8％) in the simple group,the difference was statistically significant (P＜0.001).The median survival time in combined group was 10.6 months,which was significantly longer than 7.5 months in the simple group,the difference was statistically significant (P＜0.05).Conclusion:Biliary stent combined with 125I seed implantation in the treatment of malignant obstructive jaundice might relieve the symptom of biliary obstruction,and helped to improve cellular immune function of patients and reduce the recurrence of biliary obstruction.It had great significance to improve the quality of life of patients and prolong the survival time.

Effects of 32P intracavitary irradiation on scar formation in benign esophageal strictures / 西安交通大学学报(医学版)

Objective To establish a benign esophageal stricture model and observe the effect of 32P radioactive isotopes on benign esophageal stricture scarring with intracavitary irradiation so as to provide experimental evidence for inhibiting scar hyperplasia and preventing esophageal restenosis after endoscopic dilation for benign esophageal stricture.Methods Benign esophageal stricture models were established in 18 healthy adult rabbits by annular incision and anastomosis.Then the rabbits were randomly divided into control group,hormone group and irradiation group,with six rabbits in each group.On day 2 after surgery,we measured inner diameter of the anastomotic stoma;then the control group received saline intervention,the hormone group was given dexamethasone,and the irradiation group was given 32P radioactive isotopes.The rabbits were observed for two weeks for their general condition and weight.After the intervention,we measured inner diameter of the anastomotic stoma.Liver functions (ALT and AST) were tested again before modeling and after intervention.Then the rabbits were put to death and had tissue in the esophageal stricture area removed for pathological examination and esophageal HE staining.We determined hydroxyproline (HYP) content of esophageal tissue around the anastomotic stoma.Restlts Benign esophageal stricture model was established successfully.After 2 weeks,the rabbits' appetite was obviously diminished in control group and relatively poor in hormone group;obviously improved in irradiation group.The rabbits' weight increased in radiation group compared with the other two groups (P＜0.05).The esophageal inner diameter in irradiation group widened obviously compared with the other two groups (P ＜ 0.05).In irradiation group,the number of fibroblasts decreased obviously,collagen fiber and granulation tissue were not obvious;HYP content was lower than that in the other two groups,and was close to that in a normal esophagus (P＞0.05).ALT and AST did not differ before and after intervention in all groups (P＞0.05).Conclusion ① We can establish benign esophageal stricture model successfully through the surgery.② 32Pradioactive isotopes radiation therapy can be used to prevent early scar formation in esophageal benign stricture,and is superior to dexamethasone therapy.

Biliary stenting combined with 125I seed implantation intracavitary irradiation for the treatment of malignant obstructive jaundice / 介入放射学杂志

Objective To discuss the method, safety and clinical value of biliary stenting combined with 125I seed implantation intracavitary irradiation in treating malignant obstructive jaundice. Methods A total of 36 patients with malignant obstructive jaundice were enrolled in this study. PTCD was carried out in all patients, which was followed by biliary stenting combined with 125I seed implantation intracavitary irradiation treatment. The results were analyzed. Results During the interventional management, displacement of the stent and 125I seeds were observed in two cases, and the displaced stent and 125I seeds were replaced to the right position with the help of biliary biopsy forceps. The technical success rate was 100%, and the remission rate of the jaundice was 100%. All the patients were followed up for 1-23 months. No radioactive particles leaking or complications such as radiation enteritis occurred. No in-stent obstruction due to tumor recurrence was observed although slight dilatation of intrahepatic bile duct was detected in 25%of patients, which was resulted from intimal hyperplasia at the stent mesh and/or biliary stone formation. The median survival time was 10.9 months. Conclusion For the treatment of malignant obstructive jaundice, biliary stenting combined with 125I seed implantation intracavitary irradiation is safe, reliable and effective. This technique can prolong stent patency time as well as the patient’s survival time.

Comparison of the results between two radiotherapeutic methods for cervical cancer patients / 中国癌症杂志

Purpose:To evaluate two different methods of radiotherapy, which affect the results of cervical cancers treated and complications of the rectum or bladder. Methods:From July 1991 to December 1996, 124 cases of cervical cancer were randomly allocated into two groups. Group A (59 cases:stage Ⅰ 1, Ⅱa 12, Ⅱb 30, Ⅲa 11, Ⅲb 5) received 45—55 Gy of external radiation(ER) to the parametrium and 50—65 Gy of intracavitary irradiation (4—5 Gy per fraction, 2 fractions per week). Group B(65 cases: stage Ⅰ 2, Ⅱa 15, Ⅱb 29, Ⅲa 10, Ⅲb 9) received 26—40 Gy ER to the whole pelvic and 30—40 Gy of intracavitary irradiation (4—5 Gy per fraction, 2 fractions per week), an additional 15—29 Gy ER to the parametrium. Results:In group A, 3 year and 5 year survival rates were 81.4% and 71.7%. In group B, they were 84.6% and 70.8%. The rates of complication for the rectum were 25.4%(3 year) and 21.7%(5 year) in group A, 10.8%(3 year) and 8.3%(5 year) in group B. The rates of rectal complication( P

Intracavitary irradiation therapy for unresectable advanced for hilar cholangiocarcinoma / 临床外科杂志

Objective In this study we reported our experiences for patients with unresectable advanced hilar cholangiocarcinoma by intracavitary irradiation therapy and discussed some problemsin practice.Method 15 cases with unresectable advanced hilar cholangiocarcinoma were treated with laparotomy and operative dilatation of malignant stenosis and cathetenizing and then followed by intracavitary irradiation therapy.Result 15 cases treated by intracavitary irradiation therapy diedfrom liver function failure with biliary cirrhosis 3～18 months (average 8 months) later. None of the case died from cancer dissemination. Conclusion The patients with advanced holar cholangiocarcinoma could well tolerant of the intracavitary irradiation therapy, but they deteriolated from biliary cirrhosis about 8 months later,not from tumor dissemination.

Treatment of Carcino ma of the Uterine Cervix with High-Dose-Rate Intracavitary Irradiation using Ralstron / 대한치료방사선과학회지

From May 1979 through December 1981 a total of 524 patients with carcinoma of the uterine cervix were treated by radiation therapy with curative intent. Among the 524 patients, 356 were treated with a high-dose-rate (HDR), remote-controlled, afterloading intracavitary irradiation (ICR) system using a cobalt source (Ralstron), and 168 patients received a low-dose-rate (LER) ICR using a radium source. External beam irradiation with a total dose of 40-50 gy to the whole pelvis followed by intracavitary irradiation with a total dose or 30-39 gy in 10-13 fractions to point A was the treatment protocol ICR was given three times a week with a dose of 3 gy per fraction. Five-year actuarial survival rates in the HER-ICR group were 77.6% in stage IB (N=20), 68.2% in stage II (N=182), and 50.9% in stage III (N=148). In LDR-ICR group, 5-year survival rates were 87.5% in stage IB (N=22), 66.3% in stage II (N=91), and 55.4% in stage III (N-52). Survival rates showed a statistically significant difference by stage, but there was no significant difference between the two ICR groups. Late bowel complications after radiotherapy were noted in 3.7% of the HDR-ICR group and 8.4% of the LDR-ICR group. There was no severe complication requiring surgical management. The incidence of bladder complications was 1.4% in the HDR-ICR group and 2.4% in the LDR-ICR group. The application of HDR-ICR was technically simple and easily performed on an outpatient basis without anesthesia, and the patients tolerated it very well. Radiation exposure to personnel was virtually nil in contrast to that of LDR-ICR. Within a given period of time, more patients can be treated with HDR-ICR because of the short treatment time. Therefore, the HDR-ICR system is highly recommended for a cancer center, particularly one with a large number of patients to be treated. In order to tachieve an improved outcome, however, the optimum dose-fractionation schedule of HDR-ICRand optimum combination of intracavitary irradiation with external beam irradiation should be determined through an extensive protocol study with different treatment regimens.

Two Cases of Nasopharyngeal Carcinoma Treated with Co-60 HDR ICR / 영남의대학술지

The primary treatment modality of malignant tumors of the nasopharynx is radiation therapy owing to its inaccessibility to surgical intervention. Over the last two decades there were many changes in techniques of delivery, which include the use of higher doses of radiotherapy, the use of wide radiation field, including the elective radiation of the whole neck, the combined use of brachy- and teletherapy, and the use of split-course therapy. In spite of these advances local and regional recurrences remain the major cause of death. As a boost therapy after external irradiation, high-dose-rate intracavitary irradiation using remote control afterloading system (RALS) was used in two patients. Our results were satisfactory, however, this procedure should only be performed by those who have developed enough expertise in the use of intracavitary techniques for the treatment of nasopharyngeal cancer and have a supportive team including a physicist, dosimetrist, nurse, and trained technologist.

Early and Late Bowel Complication Following Irradiation of Cancer of the Uterine Cervix-Whole Pelvis Exlernal : Irradiation end High-Dose-Rate Inlracavitary Irradiation / 대한치료방사선과학회지

Cervix cancer is the most common female cancer in Korea. In spite of their relatively local invasive tendency, still 44% of patient will develop recurrent cancer This result suggests that more aggressive local treatment may increase the cure rate but increased complication risk also cannot be avoidable. Various institutions proposed different treatment regimen, but recommended dose were about 4500 cGy for whole pelvis and 8000 cGy at point A, even though they agreed that those doses may not be satisfactory for control of bulky disease. 96 cases of invasive cervical cancer, treated with postoperative or primary radiation therapy were analyzed to determine the complication rate and prognostic factor in our treatment regimen which is 500~1000 cGy higher than other institution. Mean follow up duration was 21 months. Symptomatic patients including mild but persistent abdominal discomfort was 46%, but only 1 patient (1%) had operative treatment because of incomplete obstruction of small bowel. Most symptoms appeared within 12 months and most common complaints were frequent bowel movement. Barium enema and sigmoidoscopy were performed for persistent symptomatic patients. Only one patient had abnormal finding in barium enema which showed inefficiency of this method for detecting bowel complication. Patient's age, total tumor dose, total TDF, rectal dose were not significant risk factors for complication, but boost dose, previous history of operation had some relationship with complication risk. Even though dose of point A and rectum is 500~1,000 cGy higher than other institution, such a low rate of severe complications may suggest that fear of complications should not be overestimated than cure rate and the possibility of more aggressive treatment for better local control should not be underestimated.

Intracavitary Irradiation of Locally Advanced Recurrent Adenocarcinoma of Rectum Along the Fistula tract / 대한치료방사선과학회지

Radiation therapy has been used as adjuvant therapy or primary treatment for inoperable, remnant or recurrent cancer. Many authors reported good palliation effect by external irradiation or interstitial therapy, but the report of intracavitary irradiation for recurrent, inoperable rectal cancer is very rare. We experienced a case of recurrent adenocarcinoma of rectum along fistula tract after laparotomy and postoperative radiotherapy who achieved very good palliation by intracavitary irradiation. Even though we have only good palliation without impressive survival improvement in this case, we hope that this technique may achieve good local control in other similar patients.