BACKGROUND & OBJECTIVES: It was difficult to get a good tissue dose distribution using fixed field irradiation technique in large field. But the translating scanning beam irradiation can make it. This study was designed to create a treatment method and to evaluate the dosimetry of translating scanning beam irradiation and the clinical indications. MATERIALS & METHODS: The dosage parameter was measured under the status of the translating scanning beam irradiation in the cobalt radiotherapy machine using a translating scanning beam irradiation device which was developed by Zhejiang Cancer Hospital and Zhejiang University. The ionization chamber method was used in the dosage measurement. RESULTS: (1) The translating scanning beam irradiation can increase the percentage depth dose. (2) The dosage homogeneous distribution is better in the translating scanning beam irradiation than fixed field irradiation. (3) There is no problem in dosage connection between two closed fields in one target volume. (4) The moving penumbra was produced in the translating scanning beam irradiation. CONCLUSIONS: According to the dosage distribution property of translating scanning beam irradiation, it has some obvious advantages in big fields irradiation (for example: total spinal cord, half body, and total body irradiation).
BACKGROUND & OBJECTIVES: It was difficult to get a good tissue dose distribution using fixed field irradiation technique in large field. But the translating scanning beam irradiation can make it. This study was designed to create a treatment method and to evaluate the dosimetry of translating scanning beam irradiation and the clinical indications. MATERIALS & METHODS: The dosage parameter was measured under the status of the translating scanning beam irradiation in the cobalt radiotherapy machine using a translating scanning beam irradiation device which was developed by Zhejiang Cancer Hospital and Zhejiang University. The ionization chamber method was used in the dosage measurement. RESULTS: (1) The translating scanning beam irradiation can increase the percentage depth dose. (2) The dosage homogeneous distribution is better in the translating scanning beam irradiation than fixed field irradiation. (3) There is no problem in dosage connection between two closed fields in one target volume. (4) The moving penumbra was produced in the translating scanning beam irradiation. CONCLUSIONS: According to the dosage distribution property of translating scanning beam irradiation, it has some obvious advantages in big fields irradiation (for example: total spinal cord, half body, and total body irradiation).