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Objective: Setup verification is the critical part to make sure of the accuracy for Intensity-modulated radiotherapy in nasopharyngeal cancer patients. This pilot study was designed to answer whether and how much the kV-CBCT in addition to 2DkV is more accurate than 2DkV alone in terms of verification parameters. Methods: Images acquisition: Offline images were displayed in the matched position between reference images. 2D and 3D matches: The bony matches were done by using the location of the tumor in the nasopharyngeal and upper neck regions. The distances displaced from the isocenter were recorded in x-y-z directions. Analysis: The distance of the isocenter shift in each direction (X, Y, Z) were presented as point estimations. The alignment between the two methods was assessed with Pearson’s and Spearman’s correlation. The 3 mm difference within 90% is considered as an acceptable range of non-inferiority of 2DkV, compared with CBCT. Results: 11 nasopharyngeal cancer patients were included into this study. The correlation between 2DkV and kV-CBCT were 0.46, 0.11 and 0.16 for Superior-inferior (SI), Anterior-posterior (AP) and Left-right (LR) directions, respectively. The central value for the kV-CBCT; SI, AP and LR directional shift were 0.07, 0.06 and 0.03 cm, respectively, whereas the central value for 2DkV; SI, AP and LR directional shift were 0.05, 0.07 and 0.04 cm. For the difference shift < 3 mm, the results > 90% were within acceptable value: 100% and 96.96% for SI and LR directions whereas the AP direction was 87.87%. Conclusion: Compared with kV-CBCT by using our criteria, 2DkV images are accurate enough for treatment verification in nasopharyngeal cancer patients.

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Objective: This study was designed to find the prevalence of anemia in cancer patients before radiotherapy and the incidence of anemia during radiotherapy treatment. The study also planned to identify factors that affect the incidence and prevalence of anemia and the management of anemia in the Division of Radiation Oncology, Siriraj Hospital. Methods: This study is designed prospectively to collect hemoglobin level and factors that might cause anemia in patients whom were treated with radiotherapy at Siriraj Hospital during April - June 2006. The eligible criteria were patients age >18 years old, had a pathology confirmed to be malignancy, and had never been treated with radiotherapy before. Patients were excluded if they were not treated with radiotherapy, had skin/central nervous system or hematologic malignancies. In this trial, anemia was defined as Hb level