Disclosed is a computer-implemented medical data processing method for determining a positional pattern of an irradiation unit for irradiating a patient with treatment radiation, the irradiation unit being part of an irradiation treatment device having an imaging device for generating a medical image of the patient, the method comprising executing, on at least one processor of at least one computer, steps of:a) acquiring (S1), at the at least one processor, irradiation unit position data describing irradiation unit positions of the irradiation unit for which the imaging device has a free viewing direction onto the position of the patient which is a free line of sight from the imaging device to the position of the patient；b) determining (S2), by the at least one processor and based on the irradiation unit position data, position orders data describing all possible orders of the irradiation unit positions for which the imaging device has a free viewing direction onto the position of the patient；c) determining (S3), by the at least one processor and based on the irradiation unit position data and the position orders data and per order described by the position orders data, intersection angle data describing a statistical quantity of the intersection angles between free viewing directions of the imaging unit for irradiation unit positions which are immediately subsequent in the order described by the position orders data；d) determining (S4), by the at least one processor and based on the intersection angle data and the position orders data, optimal order data describing an order of the irradiation unit positions for which the statistical quantity is maximal.
