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At least 109 records · Page 6Linked to original sources
PubMed1991

Megavoltage pituitary irradiation in the management of prolactinomas: long-term follow-up.

OBJECTIVE To determine the long-term effects of external beam megavoltage radiotherapy (RT: 4500 cGy via three portals at 180 cGy or less total daily dose) on endocrine function in prolactinomas. DESIGN Longitudinal study following radiotherapy with periodic re-assessment at regular intervals, at least 2 months off dopamine agonist therapy. PATIENTS Thirty-six female patients, age range 19-50 years, with either macroprolactinomas (12 patients) or microprolactinomas (24 patients), but without significant suprasellar extensions. MEASUREMENTS Clinical appraisal, and anterior and posterior pituitary assessment: basal levels at yearly intervals or less, with dynamic screening with TRH, LHRH and hypoglycaemic stimulation every 2-3 years. RESULTS Before RT, serum prolactin (PRL) levels ranged from 1150 to 34,000 mU/l; after RT (mean 8.5 years, range 3-14), serum PRL fell to normal (i.e. less than 360 mU/l) in 18 of the 36 patients (50%), and to just above the normal range (378-780 mU/l) in a further 10 (28%). Two patients had PRL levels at their last follow-up higher than those at presentation, with one patient showing evidence of tumour recurrence on CT scan. A total of eight of the 36 patients (23%) developed post-RT gonadal deficiency by the end of follow-up at 8 +/- 3.1 years (+/- SD, range 3-11), but six were aged over 40 years at that time. GH deficiency was frequent, occurring in 94% of patients, usually from 2 to 3 years post-RT, while TSH deficiency and reduced ACTH reserve was uncommon (each 14%), and occurred later. In the subgroup of 12 patients with macroprolactinomas, results were broadly comparable. CONCLUSIONS Megavoltage RT produces a progressive fall in serum prolactin in the great majority of patients with prolactinomas, with a relatively low incidence of TSH or ACTH deficiency. As it is now clear that dopamine agonist therapy alone provides sufficient management for microprolactinomas, RT may be used for the long-term control of macroprolactinomas, together with interim dopamine agonist therapy. It allows pregnancy to be safely undertaken but, in view of the delayed onset of gonadal deficiency, its administration should be timed with respect to the desired onset of conception in women.

Adrenocorticotropic Hormone↗
PubMed1984

Fibrosarcoma complicating irradiated pituitary adenoma.

Eight years after radiation therapy (5000 rads of 60Co) for a pituitary adenoma, a patient developed a sellar fibrosarcoma. The tumor had an aggressive growth pattern: it infiltrated the optic nerve, sphenoidal air sinus, hypothalamus, and both cavernous sinuses, where compression of the left internal carotid artery resulted in a massive hemispheric infarction. Surgery was ineffective in arresting rapid growth of the lesion; death occurring 5 months after onset of symptoms.

Adenoma, Chromophobe↗
PubMed1998

Megavoltage pituitary irradiation lowers but seldom leads to safe GH levels in acromegaly: a long-term follow-up study.

Radiotherapy (RT) has long been used in the treatment of acromegaly, but confusion regarding the definition of biochemical cure has hampered interpretation of previous reports on the outcome of this treatment. In the present study we present additional data using the currently accepted criteria of biochemical cure in a large group of patients followed up by our department. Forty-six acromegalic patients were treated with external beam megavoltage RT and followed up for a mean of 7.6 years (range 2-22 years). Only four patients had had previous surgical treatment by either transsphenoidal or transfrontal routes. Following RT, mean basal GH levels decreased from 30.9 ng/ml (5-96 ng/ml) to 11.5 ng/ml (1-36 ng/ml) at 10 years of follow up with a further fall to 6.1 ng/ml (1-29 ng/ml) in those patients followed up for more than 10 years. As a result, although mean GH levels of less than 5 ng/ml were achieved in 9/28 (30.1%) at 5 years, 6/19 (31.6%) at 10 years, and in 6/11 (54.5%) of those patients followed up for more than 10 years post-RT, only 0/28 (0%), 7/28 (25%), 4/19 (21%) and 1/11 (1%) achieved GH levels of <2.5 ng/ml at 2, 5. 10 and >10 years following RT. Thus, in the whole series only 10/48 (20.8%) patients showed a decrease of GH level to less than 2.5 ng/ml at their latest follow up. Hypopituitarism as a result of RT was only infrequently observed in this series; gonadal deficiency developed in 12 (26.6%) patients, thyrotrophin (TSH) deficiency in 3 (6.6%) and adrenocorticotrophin deficiency in 2 (4.4%). In conclusion, megavoltage RT is an effective treatment for the control of GH hypersecretion in acromegaly, with a continuing lowering effect for several years following RT but seldom leads to safe GH levels.

Acromegaly↗
PubMed2006

Baseline characteristics and response to GH replacement of hypopituitary patients previously irradiated for pituitary adenoma or craniopharyngioma: data from the Pfizer International Metabolic Database.

OBJECTIVE: To test the hypothesis whether the effects of GH replacement therapy in adults could be affected by prior pituitary irradiation, the baseline characteristics and response to GH were evaluated in adults with severe GH deficiency (GHD), who had received or not irradiation for the treatment of pituitary adenoma or craniopharyngioma. DESIGN: Data from 447 patients, who had received radiotherapy (427 in addition to surgery), and 630 patients, who were operated on but not irradiated for their tumour, were retrieved from Pfizer International Metabolic Database (KIMS) and compared at baseline and 1 and 2 years following the onset of GH replacement. RESULTS: Irradiated and non-irradiated patients exhibited the expected phenotype of GHD at baseline. However, irradiated patients had a greater impairment in the quality of life (QoL), a higher fat mass, lower high-density lipoprotein cholesterol levels and a lower bone mineral content (BMC) than non-irradiated patients. Treatment with GH induced similar changes in both groups. After 1 year of GH replacement, there was an increase in serum IGF-I and fat-free mass, a reduction in fat mass and an improvement in QoL, all changes being equivalent in irradiated and non-irradiated patients. The lipid profile also improved with the irradiated patients showing a better response. These beneficial effects were maintained and the BMC also increased in both groups by the second year of treatment. CONCLUSIONS: This analysis shows that prior irradiation for pituitary adenoma or craniopharyngioma does not compromise the beneficial effects of GH replacement therapy.

Adenoma↗
PubMed1991

Blindness in patients after external beam irradiation for pituitary adenomas: two cases occurring after small daily fractional doses.

We report two cases of blindness occurring within 10 months of completion of radiation with 45 Gy in 1.80 Gy fractions given five times weekly. The literature on blindness as a complication of pituitary irradiation is reviewed. There have been no reported cases of total visual loss occurring as a consequence of treatment with fractional doses of less than 2 Gy. Visual loss due to radiation damage usually occurs within two years of completion of treatment in contrast to visual loss due to recurrence or empty sella syndrome, which usually occur more than two years after the completion of therapy. Other causes of blindness not related to the radiation, and potentially reversible, must be considered. However, these causes usually have a distinctively different clinical picture. Fraction size, total dose, and treatment time are all important factors when considering the biological effects of radiation to the pituitary region.

Adenoma↗
PubMed2002

Histological changes in the pituitary gland and adenomas following radiotherapy.

To elucidate histological changes in the pituitary gland and adenomas following radiotherapy, two irradiated pituitary glands and seven irradiated non-functioning adenomas were studied. The latter included four cases with conventional radiation (CR) and three cases with radiosurgery: two with gamma knife radiosurgery (GKR) and one with stereotactic fractionated radiotherapy (SRT). The specimens were obtained 10 months to 10 years (mean 58 months) after the radiotherapy. Irradiated pituitary glands showed diffuse fibrosis in the adenohypophysis, whereas irradiated adenomas showed either mild or no fibrosis in five CR/SRT cases and diffuse thick hyaline deposits in two GKR cases. No necrosis was observed. Stellate-shaped S-100 protein-positive cells were greater in number in the irradiated pituitary glands than in the normal glands. Pituitary cells with dense granular reactivity for mitochondrial protein, cytochrome oxidase, and Mn-SOD, mimicking oncocytes, were greater in number in the irradiated adenohypophysis but did not show any change in cell size. Many irradiated pituitary cells and some irradiated adenoma cells were densely positive with anticytokeratin 1,5,10,14 antibody whereas non-irradiated counterparts were negative. In adenomas, MIB-1 labeling index remained unchanged after the radiation. The results may indicate that radiation-induced fibrosis was associated with an increased number of folliculo-stellate cells, mitochondrial dysfunction, and squamous metaplasia. These findings were prominent in irradiated pituitary cells and may participate in delayed pituitary hypofunction following radiotherapy. In irradiated adenoma cells, similar findings were observed but diffuse fibrosis was absent. The histological changes were more intensive in adenomas following GKR than those following CR.

Adenoma↗
PubMed1992

Re-irradiation of pituitary adenoma.

Fifteen patients initially irradiated for pituitary adenoma were subsequently treated with a second course of radiotherapy at the University of California at San Francisco between 1961 and 1989. The re-irradiation followed surgery in all but two cases. The median time to recurrence was 9 years (range 2-17) and median follow-up after the second course of radiotherapy was 10 years (range 1-30). The median initial radiation dose was 4084 cGy; that at recurrence was 4200 cGy. Local control has been maintained in 12 patients. One failed locally with a benign adenoma that was surgically salvaged. Two developed pituitary carcinomas which were poorly controlled. Of the patients who presented with visual abnormalities at the time of recurrence, 50% improved and the remainder stabilized after re-irradiation. There are no long-term visual complications. Hypopituitarism was present in nine patients prior to the second course of radiotherapy and developed in the remaining six patients after re-irradiation. Temporal lobe injury was seen in two patients. Careful analysis of each patient's pituitary and temporal lobe doses, intervals between treatments, treatment volume, neurets, relative decay factors, absolute decay factors, TDF and modified LQF values, and dose-volume relationships, revealed no correlation with complication or likelihood of local control. Repeat radiotherapy for recurrent pituitary adenoma with the doses used in these patients appears to carry acceptable risk with good local control.

Adenoma↗
PubMed1995

The evolution of radiation-induced growth hormone deficiency in adults is determined by the baseline growth hormone status.

OBJECTIVE: Recent studies of GH replacement have suggested several beneficial effects for GH deficient adults. It would therefore be helpful to predict the time of onset of GH deficiency after external pituitary irradiation. We have studied the evolution of GH deficiency with time in patients irradiated for pituitary adenomas and other hypothalamic pituitary tumours. DESIGN: Analysis of serial peak GH responses to insulin hypoglycaemia following external irradiation to the hypothalamic-pituitary axis using statistical models which allowed for age, sex, previous surgery and the pre-radiotherapy GH peak response. PATIENTS: Eighty-five non-acromegalic adults (48 male), 75 of whom had either a pituitary adenoma or a craniopharyngioma and 10 who had other tumours in the hypothalamic-pituitary region. All the patients had received a radiation dose between 37.5 and 45 Gy divided into 15 fractions given over 21 days. MEASUREMENTS: The GH responses to an insulin tolerance test (ITT) performed as part of the regular endocrine follow-up in patients who received irradiation to the hypothalamic-pituitary region. RESULTS: Three hundred and forty-five ITTs were performed over a period of 10 years following radiotherapy. There was a decline in the modelled mean peak GH response to an ITT over the first 5 years which then appeared to plateau. Using an extended model, women had higher GH peak responses than men and this difference was maintained throughout the ten-year period. The magnitude of the post-radiotherapy peak GH response at any given time was dependent on the baseline peak GH response, but the rate of the decrease was not affected (P = 0.66). To develop severe GH deficiency (peak GH response less than 5 mU/l) after radiotherapy it took patients with baseline GH peaks of 30, 20 and 10 mU/l approximately 4 years, 3 years and 1 year respectively. Those patients with a baseline GH peak of greater than 50 mU/l are unlikely to develop severe GH deficiency within the first 5 years following radiotherapy. CONCLUSION: These results provide an insight into the pattern of the decline in GH secretion following radiotherapy in patients with pituitary disease and the factors affecting it. This information will help the clinician predict the frequency and timing of GH deficiency in patients irradiated for pituitary disease and the potential need for GH replacement therapy.

Adolescent↗
PubMed1992

Delayed radiation necrosis of the central nervous system in patients irradiated for pituitary tumours.

Four cases of delayed radiation necrosis involving the CNS were found in a group of 46 patients irradiated for pituitary tumours over a six year period. This occurred in three of 11 patients with Cushing's disease representing an incidence of 27% in this group. There were no cases among 11 patients with acromegaly or among seven with prolactinomas. One case (6%) was found in the 17 patients with chromophobe adenomas. Standard doses of radiation were delivered to these patients and the findings support suggestions that the metabolic disturbances of Cushing's disease may reduce tolerance to radiation. Our results and a literature review indicate that if radiotherapy is used to treat Cushing's disease, the total dose should be less than 50 Gy at 2 Gy per day fractionation.

Adenoma↗
PubMed1976

Decrease of the sella turcia to normal size, a major sign of the effectiveness of pituitary tumour irradiation.

In this preliminary paper, the authors review 20 cases of pituitary tumours, with sella reduction to normal size, associated to the biological recuperation and social rehabilitation of most patients, after conventional radiation therapy given in high-dose courses. It is evaluated that sella reduction to normal size, whenever encountered, can be considered as the major anatomico-radiological sign of the effectiveness of different therapeutical methods applied in the case of secretory and non-secretory tumours.

Adolescent↗
PubMed1998

Cobalt 60 irradiation of pituitary gland tumors in three cats with acromegaly.

Acromegaly was diagnosed in 3 cats with insulin-resistant diabetes mellitus (DM) on the basis of history and physical examination findings, which ruled out other causes of insulin-resistant DM, and by documenting high plasma concentrations of growth hormone. Computed tomography revealed a mass in the area of the pituitary gland in each cat. Pituitary gland tumors were irradiated with cobalt 60, and none of the cats developed complications to radiotherapy. Each cat received a total dose of 48 Gy of cobalt 60 during 12 treatments. After completion of radiotherapy, insulin requirements were less for all cats, although in 1 cat, this improvement was transient. Diabetes mellitus resolved in 2 of 3 cats. After treatment, decreases in insulin requirements correlated with decreases in plasma growth hormone concentrations in 2 of 3 cats in which DM resolved. On the basis of these findings, irradiation of pituitary gland tumors appears to be a treatment option for cats with acromegaly.

Acromegaly↗
PubMed1984

Treatment of Cushing's disease with low dose radiation therapy.

Nineteen patients with Cushing's disease were treated with low dose external pituitary irradiation (20 Gy (2000 rad) in eight fractions over 10 days). While awaiting the effects of pituitary irradiation all patients were treated with metyrapone. Seven patients had a complete remission of their disease within six to 12 months of irradiation. They did not require any further treatment and were followed up for a mean of three and a half (range one to eight) years. Another patient had a complete remission after a second course of pituitary irradiation. A further two patients showed a significant biochemical improvement after irradiation, although they were not rendered eucorticoid. There were no complications after this dose of irradiation. These results compare favourably with those reported after pituitary irradiation at conventional doses (40-50 Gy (4000-5000 rad) over four or five weeks) but were not associated with any complications. It is therefore recommended that low dose external pituitary irradiation be used as definitive first line treatment for Cushing's disease.

Adolescent↗
PubMed1985

[Dynamics of the bioelectrical activity of the brain in patients with intrasellar pituitary adenomas irradiated with a proton beam].

Sixty patients with pituitary endosellar adenomas irradiated with the proton beam were examined using EEG prior to and following irradiation in the period ranging from 14 days to 3 years. Fourteen days to three months after the proton irradiation, intensified irritation of the diencephalic structures was recorded. Later on, gradual normalization of bioelectrical activity was observed. Local changes in the temporal lobes, probably associated with the tissue response to irradiation by the proton beam were noted only in 8 out of the 60 patients.

Brain Diseases↗