Volumetric modulated arc therapy for carotid sparing in the management of early glottic cancer

PURPOSE: Radiotherapy of the neck is known to cause carotid artery stenosis. We compared the carotid artery dose received between volumetric modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (IMRT) plans in patients with early glottic cancer. MATERIALS AND METHODS: Twenty-one early glottic cancer patients who previously underwent definitive radiotherapy were selected for this study. For each patient, double arc VMAT, 8-field IMRT, 3-dimensional conformal radiotherapy (3DCRT), and lateral parallel-opposed photon field radiotherapy (LPRT) plans were created. The 3DCRT plan was generated using lateral parallel-opposed photon fields plus an anterior photon field. VMAT and IMRT treatment plan optimization was performed under standardized conditions to obtain adequate target volume coverage and spare the carotid artery. Dose-volume specifications for the VMAT, IMRT, 3DCRT, and LPRT plans were calculated with radiotherapy planning system. Monitor units (MUs) and delivery time were measured to evaluate treatment efficiency. RESULTS: Target volume coverage and homogeneity results were comparable between VMAT and IMRT; however, VMAT was superior to IMRT for carotid artery dose sparing. The mean dose to the carotid arteries in double arc VMAT was reduced by 6.8% compared to fixed-field IMRT (p < 0.001). The MUs for VMAT and IMRT were not significantly different (p = 0.089). VMAT allowed an approximately two-fold reduction in treatment delivery time in comparison to IMRT (3 to 5 minutes vs. 5 to 10 minutes). CONCLUSION: VMAT resulted in a lower carotid artery dose compared to conventional fixed-field IMRT, and maintained good target coverage in patients with early glottic cancer.

A Nationwide Epidemiological Study of Testicular Torsion in Korea

Testicular torsion is a surgical emergency in the field of urology. Knowledge of the epidemiology and pathophysiology is significant to an urologist. However, the epidemiology of testicular torsion in Korea has not been studied. We performed a nationwide epidemiological study to improve knowledge of the epidemiology of testicular torsion. From 2006-2011, the Korean Urologic Association began the patient registry service. The annual number of patients with testicular torsion from 2006 to 2011 were 225, 250, 271, 277, 345, and 210, respectively. The overall incidence of testicular torsion in males was 1.1 per 100,000; However, the incidence in men less than 25 yr old was 2.9 per 100,000. Adolescents showed the highest incidence. Total testicular salvage rate was 75.7% in this survey. There was no geographic difference of testicular salvage rate. Minimizing the possibility of orchiectomy for testicular torsion is important to improve public awareness to expedite presentation and provider education to improve diagnosis and surgery.

Predictive Value of Preoperative Unenhanced Computed Tomography During Ureteroscopic Lithotripsy: A Single Institute's Experience

PURPOSE: Ureteroscopic stone removal is frequently used to remove ureteral stones. Mucosal edema and bleeding are the two most important obstacles to a successful operation. This study analyzed relationships between unenhanced computed tomography (UECT) findings and ureteroscopic findings to determine whether ureteroscopic results could be predicted preoperatively by using UECT imaging. MATERIALS AND METHODS: From January 2009 to July 2011, 675 patients were diagnosed with ureteral stones through UECT. Among them, we retrospectively reviewed 92 cases of patients who underwent ureteroscopy (URS). We identified findings such as hydronephrosis, rim sign, periureteral fat stranding, and perinephric fat stranding on the UECT and then categorized these findings into four categories (none, mild, moderate, and severe) according to their severity. We also divided the URS findings of mucosal edema and bleeding into four categories (none, mild, moderate, and severe) and compared these findings with the UECT images. RESULTS: A total of 92 study patients were included in this study: 59 were male and 33 were female patients. According to the location of the stone, 31 cases were classified as upper ureteral stones, 15 were midureteral stones, and 46 were lower ureteral stones. Hydronephrosis identified with UECT was correlated with the mucosal edema severity observed during URS (p=0.004). The rim signs identified with UECT were proportional to the grade of mucosal edema (p=0.010). CONCLUSIONS: Hydronephrosis and rim signs observed during UECT can be used as a predictive factor for intraoperative mucosal edema in patients undergoing URS.