16 Cervix Carcinoma

Cervix Cancer 323

Fig 14.10: Modern Manchester method (A2)

Fig 14.10B: Modern Manchester Method: Lateral and AP radiographs indicating the adequate position of the applicator, a gold seed inserted in the right posterior lip and a large individual vaginal gauze pack pushing the rectum away from the ovoids (from 59). A correction factor for the reduction of total dose was introduced (see below). An adaptation of the standard dose distribution is performed, if the maximum dose measured by a rectal probe (5 points) is greater than two thirds of the dose to point A. The AP “pear” and lateral “banana” shaped volume defined by the isodose going through point A (reference dose) is dependent on the length of the intrauterine tube and the size of the ovoids employed. In practice this varies between 101 and 155 cm 3 . The corresponding 60 Gy isodose volumes for the definitive treatment of small volume disease by brachytherapy alone vary between 120 and 185 cm 3 (60). There is no adaptation of the standard source arrangements to the individual tumour volume and the only differences between the treatments is dictated by the external beam dose and its distribution.