Treatment of cystic craniopharyngiomas with yttrium-90 colloid solution.

The authors analyzed long-term follow-up data to assess the value of intracavitary irradiation with stereotactically implanted beta-emitting radioisotope (90)Y-silicate colloid for the treatment of craniopharyngiomas. Fifty-seven craniopharyngiomas in 42 patients were selected for retrospective analysis. The yttrium-90 was implanted intracavitally, using computerized tomography-guided and three-dimensional stereotactic treatment planning. The cumulative dose aimed at the inner surface of the cyst wall was 300 Gy. An average of 75% shrinkage of the initial cyst volume was observed. In 18 cases the reduction was more than 91%, and the cyst disappeared totally in 11 cases. A 50% decrease in cyst volume was usually apparent between the 2nd and 4th months. A 70% decrease in cyst volume was seen by the 5th and 6th months and an 80% reduction by the 7th and 8th months. Cysts that were unchanged remained so throughout the observation period. The time course of volume reduction could be expressed mathematically by the formula of 0.73 X e(-0.62 X T) + 0.27, where "e" is the basic number of natural logarithm and "T" is the time expressed in months. Mean survival duration after intracavitary irradiation was 9.4 years. The shrinkage of the cyst was a consequence of fibrosis of the wall, as seen on histopathological examination. The neuroophthalmological prognosis was favorable only when the optic disc was normal or nearly normal at the time of the treatment. In the presence of preexisting optic atrophy, visual deterioration proved to be irreversible. The long-term results support the view that intracavitary (90)Y-irradiation is a noninvasive and very effective method of treatment for craniopharyngioma cysts. Because of the 1.1 mm half-life decay of beta irradiation, it cannot influence the solid part of the tumor; therefore, the best result can be expected in solitary cysts.

A case of paradoxical worsening of dural-sinus arteriovenous malformation syndrome after neurosurgery.

The authors present a case of a patient with the syndrome of paradoxical worsening of dural-sinus cavernous arteriovenous malformation which was a iatrogenic consequence of embolization of the basal branches of a dural shunt with Yvalon. It is presumed that the thrombogenous Yvalon reached the basal branches of the medial meningeal artery to the superior ophthalmic vein, where it caused complete thrombosis. The impaired ocular and orbital venous outflow caused a dramatic worsening of the ocular congestive symptoms: venous stasis retinopathy with dilated veins, flame-and dot-shaped hemorrhages and a secondary increase in intraocular pressure. The diagnosis of thrombosis of the entire superior ophthalmic vein was confirmed by color Doppler imaging. The mechanism is discussed. Although the ocular pathology is usually self-limiting following the establishment of collateral venous outflow channels, in view of the patient's serious congestive ocular symptoms argon laser photocoagulation and conservative antiglaucomatous local therapy were applied. Once orbital collateral venous drainage was established, the ocular symptoms improved. In the one-year follow-up there was no other complication.

[Persistent trigeminal artery associated with pituitary adenoma]. / Hypophysis adenomával társult persistáló intrasellaris arteria trigemini primitiva.

The authors report of a case with a pituitary macroadenoma which was associated with a persistent trigeminal artery. The tumour was removed by transsphenoidal microsurgical approach to the sella turcica. To recognise the developmental anomaly is very important to avoid complications during operation.

Pathological changes in cystic craniopharyngiomas following intracavital 90yttrium treatment.

Radiosurgery, using 90Y injected directly into the cavity of cystic craniopharyngiomas produces remarkable reduction of tumour size and diminishes cyst fluid production. The authors have studied the histology of biopsy and autopsy material obtained from seven patients presented with cystic craniopharyngiomas. Histological examination was carried out before and after 90Y silicate implantation. As an effect of 90Y irradiation, histology of samples taken from the cyst wall revealed that the lining epithelial cell layer became destroyed and the cyst wall shrunk. Large amount of collagen fibres with focal hyaline degeneration was present. Proliferation of intimal cells and subendothelial connective tissue narrowing small vessel lumina also occurred. Considering that fibrotic tissue is more susceptible to shrink, the fibrosis induced by irradiation together with destruction of the squamous epithelium and vascular changes, might explain the reduction of the cyst volume and diminished fluid secretion after 90Y treatment.

[Intracystic instillation of yttrium 90 silicate colloid in cystic craniopharyngioma]. / Cystás craniopharyngeomák intracavitalis ittrium-90 szilikát kolloid kezelése.

The authors evaluate the intracavital treatment with 90 Yttrium silicate colloid given in 31 occasion in 26 patients of cystic craniopharyngioma. The method has been applied since 1975 in the National Institute of Neurosurgery Budapest, using practically the same method as described by Backlund et al. (1972). Although the intracavital treatment was only one among several applied forms of treatment (resection, aspiration, shunting etc.) the effectiveness of the internal irradiation is obvious. The main effect is shrinkage of the cyst. At the 26 patients there was an average of more than 70% volume decrease of the cysts. In 5 cases the cysts totally disappeared and only on two occasions the volume has remained unchanged. Neuroophtalmological data: Preoperatively visual field defects or an impairment of visual activity have been observed in 24 out of the 26 patients studied. After the 90-Yttrium treatment the ophtalmological state of the patients improved 4, worsened in 2 cases. There was no change in 18 cases. The neuroophtalmological prognosis was good only when a relatively intact optic disc was seen; when the disc was atrophic the visual deterioration proved to be irreversible. Pathologically, the fibrotic tissue is responsible for the shrinkage of the cyst.

Further experiences in the treatment of cystic craniopharyngeomas with yttrium 90 silicate colloid.

20 patients suffering from cystic craniopharyngioma were treated with intracavitary irradiation on 25 occasions. The beta emitting radionuclide 90Y silicate colloid was instilled into the cyst or cystic part of the tumour. 17 patients on 22 occasions underwent follow-up CT and ophthalmological examinations 1 to 144 (average: 34) months after the intracavitary radioisotope therapy. An 23 occasions there was an average of 82 to 90% volume decrease of the craniopharyngioma cysts. On two occasions the volume has remained unchanged and the result of the 90Y therapy cannot be evaluated yet. The neuroophthalmological prognosis was good only when a relatively intact optic disc was seen; when the disc was atrophic the visual deterioration proved to be irreversible. Pathologically, it is the fibrotic tissue that is responsible for the shrinkage of the cyst.

The radiotherapy of cystic craniopharyngioma with intracystic installation of 90Y silicate colloid.

The authors describe the intracavital treatment with 90Y silicate colloid in 9 cases of cystic craniopharyngioma. The method has been applied since 1975 in the National Institute of Neurosurgery, Budapest. The intracavital treatment was only one among several applied treatment forms. In all patients a partial removal of the tumour has also been performed. The possibilities of evaluation of the effectiveness of the internal cyst irradiation are therefore limited. In most cases the intracavital treatment resulted in shrinkage of the cyst, or even was followed by its practical disappearence and the condition of the patients shows a decisive improvement. The growth of solid tumour parts is not influenced by this kind of treatment. Therefore the clinical improvement of the patient's condition depends also on the ratio between cyst and solid tumour volume. The optic nerve impairment did not improve in all cases. As a side-effect an oculomotor nerve paresis developed in several patients. Its possible explanations have been discussed, including lasting damage from tumour pressure.

Experiences in the endovascular treatment of cerebral arteriovenous angiomas.

Percutaneous superselective balloon catheterization for the treatment of large cerebral arteriovenous malformations, for which direct operation is infeasible, is described. Both a detachable balloon technique and a "calibrated leak" free embolization have been applied, based on a new hardening silicone material elaborated by the authors. The experiences of operations performed since 1978 are represented by four selected case studies.

Significance of balloon catheter selective and superselective angiography in the diagnosis of cerebral vascular malformations.

The significance of superselective angiography in obtaining information concerning the haemodynamics of arteriovenous angiomas and certain saccular aneurysms in emphasized on the basis of evidence obtained in 17 cases.