Objective To evaluate the efficacy and safety of dorsal onlay buccal mucosa urethro-plasty for the treatment of long anterior urethral stricture. Methods From October 2005 to SeDtem-ber 2007,57 patients(17-52 years old)underwent buccal mucosal dorsal onlay urethroplastv for the treatment of anterior urethral stricture.The mean urethral stricture length was 3.0cm(2.5-7.0 cm).Previously,29(51%)patients had experienced one direct vision internal urethrotomy(DVIU),20(35%)patients had accepted twice DVIU and 8(14%)patient had 3 times DVIU for the treatment of urethral stricture.All patients recurred urethral stricture after DVIU.The length of urethral stric-ture was measured by combined retrograde urethrography and voiding cystourethrography before ure-throplasty.All patients accepted urethroplasty at more than 6 months after last failed surgery.Buccal mucosa was harvested from right cheek.The urethra was exposed and dors'al side was rotated to out-side. A longitudinal incision was made on urethra. Buccal mucosal free grafts were sutured to the open edges of urethra with 6-0 absorbable suture. 1 8 F silicon fenestrated urethral catheter was Dlaced and kept for 4 weeks. Urethrography was used at 4 weeks and 3 months after the urethroplastv,and thenevery 6 months to evaluate the urethral recovery.Dysuria and urethral caliber less than 1 6 F which was confirmed by urethrography and urethroscopy were regarded as stricture recurrence. Resuits The mean fellow-up time were 11.2 months(1-23 months).Fifty-four(95%) patients remained stricture free.Three(5%)patients recurred at the 2 to 3 months after the operation and were treated with DVIU.Three patients had wound infection and recovered without other complication.There was no fistula,diverticulum in all patients.The pain of cheek lasted for 2 5 days(average 2.3 days).No case had hypoesthesia of cheek,obstruction of stenseffs duct or cheek scar.Conclusions Dorsal on-1ay buccal mucosal urethroplasty for long anterior urethral stricture provides stable results with few and acceptable complications.

Objective To verify the reliability of radiotherapy dosimetric parameters in reference and non-reference conditions using thermoluminescent dosimeters (TLDs).Methods Using the established TLD method,the dose variations with different radiation field sizes and 45 ° wedge plate were verified for 10 photon beams of 6 MV,together with dosimetric parameters at the point of maximum axial dose for 4 electron beams of 9 MeV under reference and non-reference conditions.Comparisons were made between TLD results and finger ionization chamber results.Results The average relative deviation,for 6 MV photon beams,between TLD results and finger ionization chamber measurements was 4.7％,within ± 7％ as required by the IAEA.The average relative deviation,for 9 MeV electron beam,between TLD results and plane parallel ionization chamber measurements was 2.4 ％,not beyond ± 5％ permitted by IAEA.Conclusions Using TLD method to verify the radiotherapy dosimetric parameters in reference and non-reference conditions was reliable,simple and feasible.

Objective To validate the absorbed dose and two-dimensional dose distribution from photon beam by using Thermoluminescent dosimeter (TLD) and film for intensity modulated radiation therapy (IMRT).Methods A total of 8 medical accelerators were selected among 5 third-grade first-class hospitals using non-probabilistic sampling method in Henan province.TLDs were put into polytetrafluoroethylene solid phantom with size of 5 cm × 15 cm × 15 cm provided by IAEA.After CT scanning,the radiotherapeutic plans were formulated through image transmission to the treatment planning system (TPS).The IMRT plan was implemented for measurement of TLD-absorbed doses under the conditions of 5 cm × 5 cm field,90 cm SSD,10 cm depth,6 MV photon beam and 6 Gy absorbed dose and corresponding measurement unit (MU).The 25 cm × 25 cm film-absorbed dose measurement was made in the same manner as TLD under the conditions of 30 cm × 30 cm size,20 cm thickness,95 cm SSD and 5 cm depth.Results Of eight accelerators,the requirements can be met for 7 accelerators with respect to the relative deviation of TLD absorbed dose except 1.For film,relative deviations were all consistent with the requirements.The passing rate of two-dimensional dose distribution was in line with the requirements for 7 accelerators except 1.Conclusions TLD and film can be used to check the MLC field absorbed dose and two-dimensional dose distribution.This methodis simple,easy to operate and suitable for the implementation of IMRT quality control in hospitals in Henan province.

In order to analyze the image noise effect on the results of Gamma knife dosimetry parameter test, we tested the dosimetry parameters of the Gamma knives according to GBZ 168-2005. Radiological protection standards of X (gamma)-ray stereotactic radiosurgery for head treatment. Dose analysis software was applied to examine the testing film before and after image denoising, and SPSS 11.0 software was used for statistical analysis. The results showed that there was a significant difference in the results of the maximum deviation between radiation field size and its nominal value (t = 7.600, P < 0.01) and the radiation field's penumbra region width of collimators also had significantly different sizes (t = 5.334, P < 0.01) before and after image denoising. This study indicated that the image noise could influence the results of testing Gamma knife dosimetry parameters, so as to cause deviations.
Algorithms ; Artifacts ; Gamma Rays ; Head ; surgery ; Humans ; Radiometry ; instrumentation ; Radiosurgery ; instrumentation ; Radiotherapy Planning, Computer-Assisted ; methods ; Stereotaxic Techniques

Objective:To investigate the efficacy and safety of bladder neck resection combined with multipoint injection of triamcinolone acetonide in the treatment of bladder neck contractures (BNC) after transurethral resection prostate (TURP).Methods:The data of 25 patients with BNC after TUPR who underwent transurethral surgery in West China Hospital of Sichuan University from July 2019 to November 2021 were retrospectively analyzed, and the patients were divided into 2 groups according to the treatment method. There were 15 cases in the steroid injection group, with an average age of (67.5±8.8) years, 1 case of diabetes, and 2 cases of hypertension. And the average postoperative time after TURP was (21.9±29.1) months, the preoperative International Prostate Symptom Score (IPSS) was (30.0±3.5) points, quality of life (QOL) score was (5.7±0.5) points. There were 10 cases in the non-steroid injection group, with an average age of (65.2±10.5) years, 1 case of diabetes, and 2 cases of hypertension. And the average postoperative time of TURP was (29.3±33.5) months, and the preoperative IPSS was (30.4±2.6) points, QOL score was (5.8±0.4) points. There was no significant difference between the two groups ( P>0.05). In the steroid injection group, bladder neck resection combined with multipoint injection of triamcinolone acetonide was performed. The patients were in the lithotomy position, and a scope was placed through the urethra into the distal end of the narrow urethra under direct vision for observation, and a supersmooth guide wire was placed. The narrow section is then incised at 6 o'clock. After replacing the resectoscope, the urethral stricture scar was excised until the normal tissue of the bladder neck was exposed. Hemostasis by electrocoagulation resulted in no active bleeding from the urethra after resection. After the bladder injection needle was inserted, 80 mg (12 ml) of triamcinolone acetonide injection was injected in 6 equally spaced needles at the direction of the bladder neck from 3 to 9 o'clock. A supersmooth guide wire was placed, and a three-channel silicone urinary catheter was indwelled along the guide wire. The non-steroid injection group underwent simple bladder neck resection. Re-examination of urethroscopy at 3 and 6 months after operation showed that the patient had obvious dysuria and the microscopic examination showed that the recurrence of bladder neck stenosis was defined as the recurrence of stenosis. The efficacy, complications, and recurrence-free survival rates of the two groups were compared. Predictors of postoperative BNC recurrence were analyzed. Results:The operations in both groups were successfully completed. The operation time of the steroid injection group and the non-steroid injection group were (36.0±17.8) min and (48.5±57.9) min respectively ( P=0.438), and the intraoperative blood loss was (1.9±3.0) ml and (12.0±31.1) ml ( P=0.221)respectively. The length of hospital stay was (5.8±1.2) d and (4.4±2.5) d, respectively ( P=0.070). There was 1 case of transient hematuria and 1 case of epididymitis in the steroid injection group, and 1 case of transient hematuria and 1 case of transient dysuria in the non-steroid injection group ( P>0.05), all of which were relieved after symptomatic treatment. The IPSS of steroid injection group and non-steroid injection group were (11.0±5.6) points and (12.4±3.9) points at 3 months after operation, and (10.1±4.9) points and (14.7±7.7) points at 6 months after operation, respectively. QOL at 3 months after operation was (1.7±1.2) points and (2.1±1.5) points, respectively, and at 6 months after operation, it was (1.5±1.3) points and (3.0±2.0) points, respectively. There was statistical significance ( P<0.05). There were 1 case and 2 cases of recurrence in the steroid injection group and non-steroid injection group at 3 months after operation ( P=0.543), and 1 case and 5 cases at 6 months after operation ( P=0.023). The difference in survival curve between the two groups was statistically significant ( P=0.013). Combined steroid therapy ( OR=14.000, 95% CI1.299-150.889, P=0.030), time after scar resection ( OR=1.138, 95% CI1.017-1.273, P=0.025), postoperative IPSS( OR=1.302, 95% CI1.018-1.666, P=0.036), postoperative QOL score ( OR=4.280, 95% CI1.523-12.030, P=0.006) were the predictors of stenosis recurrence 6 months after surgery. Conclusion:Bladder neck scar resection combined with steroid injection could be safe and effective in the treatment of BNC after TURP, and local steroid injection may help reduce the recurrence rate of postoperative stenosis.

Objective: To use TLDs and radiochromic films to verify the prescribed doses to both planned target volume (PTV) and organ at risk (OAR) and the 2D dose distribution in IMRT. Methods: Eight accelerators of different models were selected in Henan province. The polystyrene phantom provided by IAEA was scanned using CT scanners and then the scanned images were transmitted to treatment planning system (TPS) for prescribing respectively the doses to PTV and OAR. IMRT was performed with phantom exposed to a 6 MV X-rays. The irradiated TLDs and films were delivered for measurement and estimation at Secondary Standard Dosimetry Laboratory at National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention. Results: According to IAEA requirements, the relative deviations of the TLD-measured and TPS-planned values were within ±7.0% for the prescribed doses to PTV and OAR. The measured results for PTV have shown that the relative deviation of TLD-measured and TPS-planned values were within -0.3% to 6.9% for 8 accelerators, all consistent with the IAEA requirements. For OAR, the relative deviations of TLD-measured and TPS-planned were within -7.0% to 0.3% for 6 accelerators, consistent with the requirements, whereas those for other 2 accelerators were within -10.8% to -8.4%, not up to the requirements. IAEA required that, for 2D dose distribution, the pass rate of 3 mm/3% be ≥90%. The measured values for 7 accelerators were from 90.2% to 99.9%, consistent with the requirements, whereas that for another one was 70.0%, not meeting the requirement. Conclusions The method to verify, using radiochromic film and TLD, the prescribed doses to PTV and OAR and the pass rate of 2D dose distribution is simple and reliable. It is an important step to implement quality control for IMRT and can provide effective support for medical or third-party service institution to verify clinically prescribed dose.

Rats ; Animals ; Urinary Bladder Neck Obstruction/pathology* ; Survivin/genetics* ; Urinary Bladder/pathology* ; Fibrosis