A)

Simple

(i)

Patient outlines e.g. bladder, chest, rectum, prostate

(ii)

Lead cut outs

(iii)

Craniospinal gap changes

(iv)

Reduction of field sizes e.g. brain protocol

B)

Intermediate

(i)

Cerobend shielding blocks

(ii)

Head and neck shells, e.g. brain, pituitary, larynx

(iii)

Lead cut outs requiring impressions

(iv)

Electron shells

(v)

Cobalt 60 wax blocks, e.g. nose

(vi)

Orfit shells

C)

Complex:

(i)

Head and neck shells with mouth bites and/or waxes

(ii)

Angled down fields for head and neck

(iii)

Pinna moulds

(iv)

Craniospinal shells

(v)

Cathetron moulds