Effects of Molsidomine on Retinopathy and Oxidative Stress Induced by Radiotheraphy in Rat Eyes.

PURPOSE: To determine the role of Molsidomine in preventing radiation-induced retinopathy after head and neck region irradiation of rats with a single radiation dose of 15 Gy. MATERIALS AND METHODS: Male Wistar albino rats were randomly grouped into five as follows: (1) control group rats, which were applied through an intraperitoneal (i.p.) vehicle without radiotherapy (RT); (2) RT group rats received a single dose of 15 Gy irradiation and after daily 0.1 ml vehicle i.p. for 5 consecutive days; (3) molsidomine (MOL) group rats were treated for 5 consecutive days by i.p. with 4 mg/kg/day MOL; (4) irradiation plus MOL group (RT+MOL) rats received irradiation and after 10 days single daily i.p. dose of MOL for 5 consecutive days; and (5) MOL+RT group rats were treated for 5 consecutive days by i.p. with MOL before RT. At the end of the work the rats were sacrificed under high-dose anesthesia on the 16th day and then eye tissues were taken for histopathological, immunohistochemical (caspase-3), and biochemical analyses (superoxide dismutase [SOD], glutathione peroxidase [GSH], and malondialdehyde [MDA]). RESULTS: RT significantly decreased both the content of GSH and the activity of SOD, and significantly increased the production of MDA level in the rat eyes. MOL treatment significantly increased the SOD and GSH levels and significantly decreased the MDA production (p < 0.0001). In addition, RT significantly increased the number of ganglion cells (GCs; p = 0.001), whereas especially pretreatment with MOL improved (p = 0.013). RT led to significant retinopathy formation, and MOL therapy protected the retina from radiation-induced retinopathy (p < 0.0001). CONCLUSIONS: We suggest that MOL is a powerful antioxidant and free radical scavenger that prevents the rat eyes from radiation-induced retinopathy and oxidative stress.

Dosimetric comparison of helical tomotherapy, intensity-modulated radiation therapy, volumetric-modulated arc therapy, and 3-dimensional conformal therapy for the treatment of T1N0 glottic cancer.

Various radiotherapy planning methods for T1N0 laryngeal cancer have been proposed to decrease normal tissue toxicity. We compare helical tomotherapy (HT), linac-based intensity-modulated radiation therapy (IMRT), volumetric-modulated arc therapy (VMAT), and 3-D conformal radiotherapy (3D-CRT) techniques for T1N0 laryngeal cancer. Overall, 10 patients with T1N0 laryngeal cancer were selected and evaluated. Furthermore, 10 radiotherapy treatment plans have been created for all 10 patients, including HT, IMRT, VMAT, and 3D-CRT. IMRT, VMAT, and HT plans vs 3D-CRT plans consistently provided superior planning target volume (PTV) coverage. Similar target coverage was observed between the 3 IMRT modalities. Compared with 3D-CRT, IMRT, HT, and VMAT significantly reduced the mean dose to the carotid arteries. VMAT resulted in the lowest mean dose to the submandibular and thyroid glands. Compared with 3D-CRT, IMRT, HT, and VMAT significantly increased the maximum dose to the spinal cord It was observed that the 3 IMRT modalities studied showed superior target coverage with less variation between each plan in comparison with 3D-CRT. The 3D-CRT plans performed better at the Dmax of the spinal cord. Clinical investigation is warranted to determine if these treatment approaches would translate into a reduction in radiation therapy-induced toxicities.

Fractionated stereotactic radiosurgery for vestibular schwannomas using cyberknife: A single institution experience.

OBJECTIVE: To assess tumour control, hearing preservation status, and complication ratio after fractionated stereotactic radiosurgery/radiotherapy by using CyberKnife device in patients with vestibular schwannomas. METHODS: This retrospective study was conducted at Izmir Ataturk Research and Tranining Hospital, Turkey, and comprised data of vestibular schwannomas patients treated with stereotactic radiosurgery/radiotherapy from March 2010 to December 2013. The patients were subjected to a dose ranging from 12 to 30Gy using CyberKnife system with an average of three fractions. SPSS 17 was used for data analysis. Paired t-test and Pearson's chi-square test were used to compare clinical parameters between groups. P<0.05 was considered significant. RESULTS: Of the 41 patients, 26(63.4%) were women and 15(36.6%) were men. The median follow-up duration after stereotactic radiosurgery/radiotherapy was 25 months (interquartile range: 9-44 months). Radiographic control evaluation ratio was 95.7% with a median follow-up of 3 years (IQR: 18.5 months). Results of 23(56%) patients showed stabile response, 17(42%) regression response and 1(2%) progression response. There were no statistically significant changes between pre- and post-stereotactic radiosurgery/radiotherapy symptoms (p>0.05). One (2.4%) patient reported new onset facial paresis. CONCLUSIONS: Stereotactic radiosurgery/radiotherapy treatment of vestibular schwannomas resulted in a good ratio of tumour control. Hearing preservation status and ratios of toxicity were comparable to published literature.

Survival and prognostic factors in patients with brain metastasis: Single center experience.

PURPOSE: The purpose of this study was to evaluate the clinical status, prognostic factors and treatment modalities affecting survival in patients with brain metastasis. We aimed to evaluate the whole brain radiation therapy (WBRT) outcomes of patients with brain metastasis in our center. METHODS: Clinical data of 315 patients referred to our center between 2004 and 2014 with metastatic brain cancers were collected and analysed for possible relationships between survival time, age, gender, Karnofsky performance status (KPS), recursive partitioning analysis (RPA), primary tumor, number of brain lesions, surgery, radiation therapy scheme, extracranial metastatic status and primary disease control status. RESULTS: The average patient age of onset was 58 years. The primary tumor site was lung (68%), breast (12%), melanoma (4%), colorectal (1.6%), sarcoma (1.3%) and unknown primary disease (4.4%). The rest of the patients had other primary sites. Eighty four (26.6%) patients had single brain metastasis, 71 (22.5%) had 2 or 3 lesions, and 159 (50.4%) patients had more than 3 lesions. Leptomeningeal involvement was seen in combination of paranchymal involvement in 11 (3.5%) patients. Fifty patients had undergone surgical resection. WBRT was delivered to all of the patients. Median overall survival was 6.7 months (95% CI, 5.80-7.74). Median overall survival of patients treated with combination of surgery and WBRT was significantly better compared with those treated with WBRT alone (13.5 vs 5.5 months, p=0.0001). One- and 2- year survival was 17 and 4.7%, respectively. CONCLUSIONS: The present study concludes that brain metastasis is common in cancer patients. The best overall survival was obtained by surgery+NBRT in good-condition patients. Treatment should be tailored on an individual basis to all these patients.

Is helical tomotherapy-based intensity-modulated radiotherapy feasible and effective in bilateral synchronous breast cancer? A two-center experience.

PURPOSE: This study describes the early clinical results and dosimetric parameters of intensity-modulated radiation therapy (IMRT) using a tomotherapy device in patients with primary bilateral synchronous breast cancer (PSBBC). METHODS: Fourteen patients with bilateral breast cancer were treated with tomotherapy between January 2011 and October 2014. The treatment planning objectives were to cover 95% of the planning target volume using a 95% isodose, with a minimum dose of 90% and a maximum dose of 107%. The organs at risk (OAR), such as the lungs, heart, esophagus and spinal cord, were contoured. Acute toxicity was recorded during and after radiation therapy. RESULTS: The advantages included better treatment conformity with lower dosages to minimize the risk to susceptible organs, such as the lungs, heart and spinal cord. There was improved coverage of the planning target volume, including the regional nodes, without any field junction problems. The median homogeneity index was 0.13 and the median conformity index 1.32. The median V20, V15, V10 and V5 for the total lungs were 18.5, 23.3, 24.2 and 60%, respectively. Skin acute toxicity was grade 1 in 72% and grade 2 in 14% of the patients. Esophageal acute toxicity was grade 1 in 43% of the patients. CONCLUSION: Tomotherapy delivers treatment that is well-tolerated, with high homogeneity and coverage indexes and the capability to reduce the irradiation dose received by the lungs and heart in PSBBC patients. This technique is therefore feasible and safe for the treatment of bilateral breast cancer.

Efficacy of stereotactic radiotherapy as salvage treatment for recurrent malignant gliomas.

PURPOSE: To evaluate the efficacy and toxicity of CyberKnife stereotactic radiotherapy (SRT) for recurrent glial tumors previously treated with high-dose radiotherapy. METHODS: CyberKnife SRT was performed in 37 patients with recurrent glial tumors who presented to our hospital between January 2007 and March 2012. The patients were subjected to a dose ranging from 20 to 28 Gy using the CyberKnife system with an average of two fractions. The median follow-up duration after SRT was 14 months (range 1.8-57). RESULTS: The median survival time of the patients after recurrence was 22.3 months (95% confidence interval/95% Cl 12.5-32). The median survival times of the high- and low-grade patients were 29 and 19 months, respectively. No significant toxicity due to radiation was noticed during the follow-up period. No factor influencing mortality was found in either the univariate or multivariate analysis. CONCLUSION: SRT using CyberKnife is an effective and safe treatment choice for recurrent glial tumors. SRT achieves a more favorable outcome in the treatment of recurrent tumors, particularly in high-grade ones.