IV. The Treatment of Carcinoma of the Cervix by a Combination of Intra-cavitary Radium and Arc Therapy

Abstract

This paper describes work done at the Marie Curie Hospital, where arc therapy has been used for the treatment of a variety of pelvic conditions. On the whole it has been found to have little or no advantage over conventional or multi-field techniques when treating large volumes, since here it is necessary to use large fields and arcs which involve irradiating through the wider diameters of the patient and often through considerable thicknesses of bone. This results in undesirably large integral doses and relatively low tumour doses. On the other hand, the technique is of definite value in treating cylinders of tissues of small diameter, since here small arcs may be used, placed in a favourable position with regard to the depth of the tumour and the presence of bone. In fact, the arc is usually placed over much the same area of the skin which would be selected for the skin fields when planning a conventional multi-field technique. This technique has been developed especially for the treatment of the parametria when supplementing the intra-cavitary radium treatment of carcinoma of the cervix, since the poor depth dose obtained in the larger patients made it impossible to give adequate irradiation to the pelvic glands through conventional anterior and posterior fields. With the introduction of arc therapy it is possible to give an additional 3000 to 4000 rads to the parametria and glands without approaching the tolerance level of the skin.