Fig. 1: Prostate cancer treatment then and now.

A Kilovoltage lateral simulator image used to set isocentre and field borders (square) based on inferential information of the prostate based on surrounding anatomy (rectal and bladder contrast, foley balloon, bony pelvis) B rotational therapy that creates an in-plane conformal delivery but lack of dynamic beams eye view shaping limits the ability to conform the beam to the actual prostate shape; such rotational delivery allowed the treatment of deep seated tumors with lower energy (1–4MV) x-rays C) image guidance using “port film” acquired by exposing an x-ray film prior to treatment showing alignment of the treatment beam (dark square) in relation to bony anatomy. D Digitally reconstructed radiograph of anterior view of pelvis reconstructed from CT imaging with superimposed contours for prostate (blue) rectum (brown) bladder (yellow) and MLC aperture design at start of a dynamic, intensity modulated arc (note the aperture is only treating part of the prostate) E conformal dose distribution from the volumetric dynamic arc therapy also demonstrating a fiducial marker used for image guidance F on board imaging used for dynamic tracking of the implanted fiducial marker during treatment.