Transaxial overlaid 50-MV radiation treatment plan on PET/CT (0 to 30 min) image. This is for three-dimensional ordered subset expectation minimization (3D-OSEM, upper) and filtered back projection (FBP, lower) reconstruction. The treatment, here shown for plane section through the normalization point (Norm), is a four-field box technique with the target dose delivery of 8 Gy in total divided equally between the four beam portals. The isodose curves displayed cover the ranges 35% (yellow), 65% (green), 85% (orange), and 95% (blue) of the total dose. The two red curves depict the interactively defined clinical target volume (inner line) and planning target volume (outer line). The gross tumor volume is not depicted but includes the prostate together with the metastasis of the right os ischii and the medial portion of the right os pubis.