A computerized dosimetric database for conformal stereotactic irradiations

An innovative computerized dosimetric database (DDB) is proposed to enable the analysis of the stereotactic radiosurgical dose distributions; it conta ins relationships between the irradiation parameters and the dose-volume da ta. Dose-volume data provide guidance to the physicist-physician team by fa cilitating the initialization of the irradiation parameters and the treatme nt planning. The presented DDB contains dose-volume data such as the 70% is odose widths and the 70%-30% isodose penumbra along the right-left, anterio r-posterior, and superior-inferior directions as a function of the irradiat ion parameters defined by the user. In order to demonstrate the usefulness of the DDB, the effects of the collimator diameter, the number of arcs, and their length on the shape of the prescription isodose surface are shown an d are related to practical considerations for the treatment plan. However, the presented DDB is one example that can be generated by the DDB system. T he planner can defne as many different DDBs as he/she wishes, which can the n be used for different investigations. This type of DDB enables us to inve stigate the irradiation technique used, to compare different irradiation te chniques, to inspect the feasibility of planning different Lesion types, or to define some dosimetric rules. The DDB provides useful interactive guide lines for the treatment planning process and replaces the voluminous dosime tric atlas. It has now been in clinical use for a year in a conformal proce dure which automatically proposes collimator diameters, are positions, and lengths allowing rapid conformal planning. (C) 1999 American Association of Physicists in Medicine. [S0094-2405(99)00604-5].