BMJ (Clinical Research Edition)
from there now report their experience in 44 patients with advanced malignant conditions (31 of breast origin) in whom up to 16 0.5 mC pellets of 9"Y were implanted by transfrontal craniotomy."2 This procedure was not without complication, and one patient developed optic atrophy, twelve extraocular palsies, seven damage to the frontal lobes, and five cerebrospinal ihinorrhoea. The operative mortality (18.1%) compares unfavourably with that recently reported for surgical hypophysectomy by 0. H.
... earson and B. S. Ray.23 The extent of destruction of the pituitary after transcranial '0Y implantation, assessed histologically at necropsy in 22 patients, varied from 20-95 %, while regression of breast cancer occurred in only 3, and arrest in a further 8 of the 31 patients treated. These results clearly show that if the skull is to be opened a more effective procedure is to remove the hypophysis surgically and destroy any remnants with either Zenker's solution23 or radioactive material.24 25 Introducing rods, pellets, or spheres of 90Y into the pituitary fossa by transnasal cannulation is a relatively simple procedure.'4 26-31 Extrasellar radiation effects are rare after this method of treatment, but about one-fifth of patients develop cerebrospinal rhinorrhoea with the risk of subsequent meningitis. Histological studies reported by M. E. S. Mahmoud32 have shown that the diaphragma sellae normally seals off the pituitary fossa from the subarachnoid space, and the association between high-placed rods and rhinorrhoeall "133 34 suggests that necrosis of this membrane is the main factor responsible for the. leak. While this can be prevented by inserting small tantalum screws in the drill holes,"7 accurate placing of the 90Y sources at a safe distance from the diaphragma is of prime importance.3' It is not easy to place free rods or pellets of 90Y regularly in an optimum position, and this also accounts for the low incidence of complete destruction of the gland after their implantation (11 of 46 cases10 28 29 35 36) These difficulties are largely overcome by the method of screw-implantation described by A. P. M. Forrest, D. W. Blair, and J. M. Valentine in Glasgow.37 By this method an yttrium rod is fixed in the centre of each half of the gland, and the precision with which they can be placed has resulted in fewer complications and consistent 98-100%