a b s t r a c tDue to its distinctive institutional background, Oman offers a valuable opportunity to examine stock price reactions to dividend announcements. In Oman, (1) there are no taxes on dividends and capital gains, (2) there is a high concentration of share ownership, (3) there is low corporate transparency, and (4) firms frequently change their dividends. Our results show that announcements of dividend increases are associated with increased stock prices, while announcements of dividend decreases cause decreases in stock prices. Firms that do not change their dividends experience insignificant negative returns. These results contradict tax-based signaling models, which argue that higher taxes on dividends relative to capital gains are a necessary condition for dividends to be informative.

BACKGROUND.Several studies have suggested that desmoplastic neurotropic melanoma (DNM) is associated with higher local recurrence rates than other types of melanoma. The authors investigated the local recurrence rates for patients with DNM after surgery alone or surgery followed by radiotherapy (RT).METHODS.One hundred twenty‐eight patients with DNM were treated at the Sydney Melanoma Unit and the Sydney Cancer Center from 1996 to 2007. All patients underwent local excision, 27 patients also received RT. For both groups, clinical and pathologic features, treatment details, and local recurrence data were analyzed.RESULTS.The median age at diagnosis was 65.5 years. The ratio of men to women was 2.7:1. The head and neck was the most common location (51%). The median Breslow thickness was 4 mm, and 99% of patients had Clark Level IV or V primary tumors. Patients who received adjuvant RT had thicker tumors (P = .003), deeper Clark level invasion (P < .001), and narrower excision margins (P < .001). There were 8 local recurrences, including 6 (6%) in the surgery only group and 2 (7%) in the adjuvant RT group. A positive margin (P < .001) and head and neck location (P = .03) were significant predictors of local recurrence.CONCLUSIONS.The local recurrence rate in this series was lower than the rates reported in historic control groups and in the authors' previous temporal cohort. The results indicated that clear surgical margins are of paramount importance in minimizing local recurrence; when margins are compromised, the addition of RT may reduce local recurrence rates compared with historic controls. A prospective randomized trial is needed to quantify the risk reduction with adjuvant RT. Cancer 2008. © 2008 American Cancer Society.

No abstract

On average, there was no significant difference in MHD between VMAT-DIBH and t-IMRT-DIBH. However, VMAT-DIBH was found to benefit a select group of patients. For patients in whom the MHD was >6.3 Gy with t-IMRT-DIBH, the use of VMAT-DIBH resulted in a benefit in reducing the MHD.

Despite advances in multimodality treatment strategies for locally advanced rectal cancer and improvements in locoregional control, there is still a considerable variation in response to neoadjuvant chemoradiotherapy (CRT). Accurate prediction of response to neoadjuvant CRT would enable early stratification of management according to good responders and poor responders, in order to adapt treatment to improve therapeutic outcomes in rectal cancer. Clinical studies in diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI have shown promising results for the prediction of therapeutic response in rectal cancer. DWI allows for assessment of tumour cellularity. DCE-MRI enables evaluation of factors of the tumour microvascular environment and changes in perfusion in response to treatment. Studies have demonstrated that predictors of good response to CRT include lower tumour pre-CRT apparent diffusion coefficient (ADC), greater percentage increase in ADC during and post CRT, and higher pre-CRT K. However, the mean ADC and K values do not adequately reflect tumour heterogeneity. Multiparametric MRI using quantitative DWI and DCE-MRI in combination, and a histogram analysis technique can assess tumour heterogeneity and its response to treatment. This strategy has the potential to improve the accuracy of therapeutic response prediction in rectal cancer and warrants further investigation.

No abstract

No abstract

No abstract