A pilot comparison study of setup verification between two-dimensional kilo-voltage (2DkV) matchand kilo-voltage cone-beam computed tomography (kV-CBCT) match for nasopharyngeal cancer patients.

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.

Prevalence incidence and management of anemia in cancer patients treated in the radiation oncology division, Siriraj Hospital.

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 radiation oncology division, 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 < 12 g/dl for both genders. Results: It was found that the prevalence of anemia within 30 days before starting radiotherapy was 54.4% and the incidence of anemia during radiotherapy was 34.3%. The frequency of anemia, defined as the number of patients in the study in whom Hb <12.0 g/dL were found at least once either at enrollment or during the survey, was 66%. Previous chemotherapy was the main predicting factor for anemia before radiotherapy. Concurrent chemo-radiotherapy patients developed a higher incidence of anemia during the survey than patients with radiotherapy alone. The incidence of anemia was highest in gynecologic malignancy patients. Only 25/112 (22.3%) of anemic patients at initial evaluation received treatment for anemia. Most of the patients were treated with a blood transfusion and none was treated with erythropoietin. Our mean trigger hemoglobin level for treatment of anemia was 9.3 g/dl. Conclusion: Anemia is common in the patients who are treated with radiotherapy in our institute with the prevalence of anemia before starting radiotherapy as high as 54.4% especially in patients previously treated with chemotharapy. One-thirds of patients developed anemia during radiotherapy, with a higher incidence in gynecologic malignancy patients and patients who receive combined chemo-radiotherapy. The total frequency of anemia in patients treated in the Division of Radiation Oncology, Siriraj Hospital was as high as 66% before and during radiotherapy.

Concurrent radiation therapy and irinotecan in stage IIIB cervical cancer.

The present study was to evaluate the efficacy and toxicity of concurrent radiation therapy and irinotecan in patients with stage IIIB cervical cancer. Fifteen patients with no prior radiation therapy and chemotherapy were enrolled in the study. These patients received 50 Gy of external radiation to whole the pelvis, 50 Gy with an additional dose of 6-10 Gy to the parametrium and 1 or 2 sessions of intracavitary Cesium-137. Weekly intravenous infusion of 40 mg/m2 irinotecan was given for 5 cycles during the course of radiation therapy. Of 14 evaluable patients, 4 (28.6%) achieved complete response and 7 (50.0%) achieved partial response. Treatment-related toxicity included grade 1 & 2 anemia, grade 1 & 2 leucopenia, grade 1 & 2 neutropenia and 7.1 per cent grade 3 diarrhea. No grade 4 toxicity or treatment-related death occurred in the present study. CONCLUSION: Irinotecan is a promising new cytotoxic agent in treatment concurrently with radiation therapy in newly diagnosed locally advanced cervical cancer. This modality of treatment appeared to be effective with acceptable toxicity.