Objective This work aims to verify and improve the dose given for cancer patients in radiation therapy by using diodes to enhance patient in vivo dosimetry on a routine basis. Some characteristics of two available semi-conductor diode dosimetry systems were evaluated. Methods The diodes had been calibrated to read the dose at D max below the surface. Correction factors of clinical relevance were quantified to convert the diode readings into patient dose. The diode was irradiated at various gantry angles(increments of 45°),various Field Sizes and various Source to Surface Distances(SSDs). Results The maximal response variation in the angular response with respect to an arbitrary angle of 0° was 1.9%,and the minimum variation was 0.5%. The response of the diode with respect to various field sizes showed the minimum and the maximum variations in the measured dose from the diode; the calculated doses were –1.6%(for 5 cm × 5 cm field size) and 6.6%(for 40 cm × 40 cm field size). The diode exhibited a significant perturbation in the response,which decreased with increasing SSD. No discrepancies larger than 5% were detected between the expected dose and the measured dose. Conclusion The results indicate that the diodes exhibit excellent linearity,dose reproducibility and minimal anisotropy; that they can be used with confidence for patient dose verification. Furthermore,diodes render real time verification of the dose delivered to patients. Objective This work aims to verify and improve the dose given for cancer patients in radiation therapy by using diodes to enhance patient in vivo dosimetry on a routine basis. Some characteristics of two available semi-conductor diode dosimetry systems were were. Methods The diodes had been Correction factors of clinical relevance were quantified to convert the diode readings into patient dose. The diode was irradiated at various gantry angles (increments of 45 °), various Field Sizes and various Source to Results The maximal response variation in the angular response with respect to an arbitrary angle of 0 ° was 1.9%, and the minimum variation was 0.5%. The response of the diode with respect to various field sizes showed the minimum and the maximum variations in the measured dose from the diode; the calculated doses were -1.6% for 5 cm × 5 cm field size and 6.6% for 40 cm × 40 cm field size. The d iode exhibited a significant perturbation in the response, which decreased with increasing SSD. No discrepancies larger than 5% were detected between the expected dose and the measured dose. Conclusion The results that that the diodes exhibit excellent linearity, dose reproducibility and minimal anisotropy; that they can be used with confidence for patient dose verification. Furthermore, diodes render real time verification of the dose delivered to patients.