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.

[The role of CT scan in cases of injury to the inferior orbital muscle]

Blowout fracture, involving the inferior wall of the orbit, causing the entrapment of the inferior rectus muscle is relatively rare, and is usually seen after traffic or sport accidents. By presenting two cases, the authors draw the attention to the necessity of careful CT scanning of the orbit, when after relatively slight trauma the patients presents with diplopia and inhibited movement of the eye. A correct investigation can establish the diagnosis and early surgery gives a full recovery of the symptoms.

[Intracystic instillation of yttrium 90 silicate colloid in cystic craniopharyngioma]

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.

[Surgical treatment of pituitary apoplexy]

Hypophysis apoplexy is a clinical syndrome characterized by the sudden development of headache, visual disturbance, associated with nausea, vomiting, signs of meningeal irritation and ophthalmoplegia. The symptoms are caused by the hemorrhage of a hypophyseal adenoma. This leads to the swelling of the tumor and compression of the perisellar structures. The authors processed the clinical and pathological characteristics of 28 cases occurring among the patient material of the National Institute of Neurosurgery of the past 10 years. According to the experiences the most important factor of a successful treatment of hypophyseal apoplexy is an early diagnosis and quick admittance to an institute of neurosurgery of satisfactory conditions. Thereafter a steroid hormone therapy of large doses and decompression operation performed by transnasal-transsphenoidal approach leads in the majority of cases to recovery.

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.