Roentgen sensitivity of cerebral tumours and so-called late irradiation necrosis of the brain

Gangliocytoma masquerading as a prolactinoma. Case report

The authors describe the case of a 36-year-old man who presented with bitemporal hemianopsia and a serum prolactin concentration of 1440 ng/ml. Magnetic resonance imaging of the pituitary revealed a presumed macroadenoma with suprasellar and temporal lobe extension. Although the patient's prolactin level was lowered to 55 ng/ml by bromocriptine therapy, no tumor shrinkage occurred. Fourteen months later, progression of visual field defects necessitated transsphenoidal resection, which was incomplete. Immunocytochemical analysis of the biopsy tissue was positive for prolactin and, in view of the clinical picture, more detailed analysis was not performed. External-beam radiotherapy was given 2 years later because of enlargement of residual tumor. Subsequently, despite a fall in the serum prolactin concentration to less than 20 ng/ml in response to the course of bromocriptine, the mass displayed further extension into the temporal lobe. Nine years after the patient's initial presentation, he underwent transfrontal craniotomy for sudden deterioration in visual acuity caused by hemorrhage into the mass. No adenohypophyseal tissue was identified in the resected tissue. The mass was composed of dysplastic neurons that were strongly immunoreactive for synaptophysin and neurofilament (indicating neural differentiation) and prolactin. Review of the original biopsy specimen indicated that the prolactin-positive cells had striking neuronal morphological characteristics. The final diagnosis in this case is prolactin-secreting gangliocytoma. Although exceedingly rare, this disease must be added to the differential diagnosis in cases of "prolactinoma" when bromocriptine therapy is followed by a marked decline in serum prolactin that is not accompanied by significant tumor shrinkage. Furthermore, in such instances, consideration should be given to "obtaining a biopsy sample prior to electing for radiotherapy.

Late radiation necrosis of the brain: case report

We report a case of radiation necrosis occurring 47 years after resection and radiotherapy for a juvenile pilocystic cerebellar astrocytoma, the longest yet reported. The patient presented with progressive lower cranial nerve dysfunction, and eventually died from cardiopulmonary arrest secondary to aspiration. The presentation, diagnosis, pathological features, and management of radiation necrosis are discussed.

Radiation optic neuropathy

Following surgery for pituitary adenoma, radiation therapy is an accepted treatment in reducing tumor recurrence. However, a potential therapeutic complication is delayed radionecrosis of perisellar neural structures, including the optic nerves and chiasm. This particular cause of visual loss, radiation optic neuropathy (RON), has not been emphasized in the ophthalmologic literature. Four cases of RON seen in the past five years are reported. Diagnostic criteria include: (1) acute visual loss (monocular or binocular), (2) visual field defects indicating optic nerve or chiasmal dysfunction, (3) absence of optic disc edema, (4) onset usually within three years of therapy (peak: 1-1 1/2 years), and (5) no computed tomographic evidence of visual pathway compression. Pathologic findings, differential diagnosis and therapy will be discussed in outlining the clinical profile of RON.

Measurements of the volume and density of intracerebral tumors by CT following therapy

For the interpretation of curative measures in patients with cerebral tumors CT is of increasing importance. The therapeutic effects can be demonstrated by close follow-up studies without any of the disadvantage of invasive neuroradiological methods. Our investigations of 125 patients with cerebral tumors are based on volume and density determinations. The CT studies of removed or inoperable tumors followed by radiation and/or cytostatic therapy prove that the best results follow a combination of both. In the present cases however, if CT proves postoperatively, at the end of radiation or at the beginning of the application of cytostatics that there is a residual mass, a complete remission cannot be obtained.

Late post-irradiation necrosis of the brain

Three examples of late post-irradiation brain necrosis are reported. In two cases operation was performed on account of the space-occupying effects of the lesions, and in the third case the lesion was found post-mortem. The aetiology and pathology of the condition are discussed. Our findings in the three cases described are contrasted with those in 29 patients who had been submitted to similar doses of irradiation, but had not developed necrosis. The literature on pathogenesis is briefly reviewed.

Malignant gliomas treated after surgery by combination chemotherapy and delayed radiation therapy. Part II. Tolerance to irradiation after chemotherapy

34 patients operated on for malignant gliomas were successively treated by combination chemotherapy with VM26 and CCNU and conventional radiation therapy with an average dosage of 5,800 Rads, six months after surgery. The general and haematological tolerance of delayed irradiation after chemotherapy was satisfactory. Twelve patients developed neurological complications during or after irradiation. The complications were early in 10 cases, and delayed in 2. They were probably due to tumour growth in five cases, and secondary to irradiation in seven. In four of the seven cases the preradiation chemotherapy seemed to potentiate the radiation effect on the central nervous system.

High-energy protons in the postoperative treatment of malignant glioma

Fractionated irradiation with high-energy protons was given postoperatively to seven patients with malignant glioma. In four cases in which detailed microscopic examinations were performed, radiation induced tumour necrosis was evident but in all four cases viable tumour cells were also observed. No abnormalities that could be attributed to radiation were observed in brain tissue free from tumour. The therapeutic results were comparable to the results achieved by other modern therapies. The results support the view that the RBE of high-energy protons is similar to that for 60Co radiation. It is suggested that a larger radiation dose, delivered by a homogeneous, well-defined proton field could possibly result in an improved therapeutic result without undue risk of injury to normal brain tissue.