Is grid therapy useful for all tumors and every grid block design?

Grid therapy is a treatment technique that has been introduced for patients with advanced bulky tumors. The purpose of this study is to investigate the effect of the radiation sensitivity of the tumors and the design of the grid blocks on the clinical response of grid therapy. The Monte Carlo simulation technique is used to determine the dose distribution through a grid block that was used for a Varian 2100C linear accelerator. From the simulated dose profiles, the therapeutic ratio (TR) and the equivalent uniform dose (EUD) for different types of tumors with respect to their radiation sensitivities were calculated. These calculations were performed using the linear quadratic (LQ) and the Hug-Kellerer (H-K) models. The results of these calculations have been validated by comparison with the clinical responses of 232 patients from different publications, who were treated with grid therapy. These published results for different tumor types were used to examine the correlation between tumor radiosensitivity and the clinical response of grid therapy. Moreover, the influence of grid design on their clinical responses was investigated by using Monte Carlo simulations of grid blocks with different hole diameters and different center-to-center spacing. The results of the theoretical models and clinical data indicated higher clinical responses for the grid therapy on the patients with more radioresistant tumors. The differences between TR values for radioresistant cells and radiosensitive cells at 20 Gy and 10 Gy doses were up to 50% and 30%, respectively. Interestingly, the differences between the TR values with LQ model and H-K model were less than 4%. Moreover, the results from the Monte Carlo studies showed that grid blocks with a hole diameters of 1.0 cm and 1.25 cm may lead to about 19% higher TR relative to the grids with hole diameters smaller than 1.0 cm or larger than 1.25 cm (with 95% confidence interval). In sum-mary, the results of this study indicate that grid therapy is more effective for tumors with radioresistant characteristics than radiosensitive tumors.

Hair salon stylists as breast cancer prevention lay health advisors for African American and Afro-Caribbean women.

OBJECTIVES: To assess the effectiveness of breast health promoting messages administered by salon stylists to clients in the salon setting. METHODS: Forty salons in an urban, minority area were randomly assigned to provide messages to clients or to serve as controls. Pre-intervention surveys were completed by 1,185 salon clients. Following program initiation, assessments of 1,210 clients were conducted. RESULTS: Among women completing surveys at control salons, 10% reported exposure to breast health messages, as opposed to 37% at experimental salons (OR 5.4, 95% CI 3.7-7.9). Self-reported exposure to stylist-delivered messages was associated with improved breast self-examination rates (OR 1.6, 95% CI 1.2-2.1) and with greater intentions to have a clinical breast examination (OR 1.9, 95% CI 1.1-3.3). CONCLUSION: Hair salons are a potentially important venue for promotion of health behaviors related to breast cancer detection.