Disease relevance of Pituitary Irradiation

• CONCLUSIONS: Octreotide is an effective treatment for acromegaly that may be used as primary therapy or after surgery and/or pituitary irradiation [1].
• Fifteen months after pituitary irradiation, he developed Nelson's syndrome, having skin hyperpigmentation, high plasma ACTH levels (376 ng/l) and a pituitary microadenoma (5 mm) documented at magnetic resonance imaging (MRI) of the pituitary region [2].
• A woman suffering from Cushing's disease from the age of 17 who had been treated consecutively with pituitary irradiation, bilateral partial adrenalectomy and o,p'-DDD (Mitotane, USP) presented the clinical picture of Nelson's syndrome (hypoadrenalism with secondary hypersecretion of ACTH and MSH) at the age of 32 [3].
• An elderly male patient with advanced prostatic adenocarcinoma, requiring increasing analgesia, underwent interstitial pituitary irradiation by implantation of yttrium-90 [4].
• The success of any treatment modality (surgery/pituitary irradiation/medical) depends on adenoma size and the extent of pretreatment GH hypersecretion [5].

High impact information on Pituitary Irradiation

• 69 patients with prolactin-secreting or growth-hormone-secreting pituitary tumours were treated with bromocriptine with or without pituitary irradiation and followed up for 6 months to 6 1/2 years [6].
• Although mitotane was given together with pituitary irradiation, initial remission was due mainly to the adrenal effect of mitotane [7].
• Other therapeutic approaches for CD, such as pituitary irradiation and medical therapy, resulted in normalization of cortisol secretion in about half of treated cases [8].
• Guanfacine inhibited GH secretion significantly in five other acromegalic patients who had been treated 5-10 yr previously by external pituitary irradiation [9].
• The other four unsuccessfully operated patients underwent pituitary irradiation and showed different and equivocal hormonal responses to desmopressin and to CRH [10].

Chemical compound and disease context of Pituitary Irradiation

• The effect of pergolide mesylate, a new potent longacting dopamine agonist, was investigated in eight patients with active acromegaly, none of whom had received pituitary irradiation [11].

Associations of Pituitary Irradiation with chemical compounds

• Sustained remission of Cushing's disease with mitotane and pituitary irradiation [7].
• One of the 13 patients who did not respond received a further course of low-dose pituitary irradiation with prompt remission and two have received metyrapone for 41 months and 15 years without ill effect [12].
• Ten of the patients studied had previously been treated by yttrium implantation, external pituitary irradiation or surgical hypophysectomy [13].
• Although clinical improvement resulted from the discontinuation of cortisone replacement therapy, urinary free cortisol levels remained elevated and the patient was treated with pituitary irradiation [14].
• However, no substantial improvement was noted in these patients, who included four receiving conventional pituitary irradiation, five receiving cyproheptadine, two receiving mitotane, and one each receiving metyrapone and phenytoin [15].

Gene context of Pituitary Irradiation

• He previously failed to respond to conventional therapeutic modalities (partial hypophysectomy, pituitary irradiation, high-dose bromocriptine and a combination of streptozotocin and 5-fluorouracil) and was treated with long-acting somatostatin analogue SMS 201-995 (Sandoz, East Hanover, NJ) [16].
• Because of a rise in the plasma ACTH level from 135 to 300 pg/ml 12 months after the start of the o,p'-DDD therapy, the dose was reduced from 6 to 2 g/day and external pituitary irradiation (4,480 rads) was initiated [17].
• The plasma TSH response to TRH was generally blunted in the patients treated with pituitary irradiation; however, none of the patients with diminished TSH reserve had signs of hypothyroidism [18].
• As well as testing tolerability a test dose of octreotide may help in determining which patients should be offered early external pituitary irradiation or therapy with a GH receptor antagonist if surgery has failed to achieve 'safe' GH levels [19].
• As GH and IGF-1 levels remained elevated she underwent external pituitary irradiation [20].

Analytical, diagnostic and therapeutic context of Pituitary Irradiation

• To examine the value of pre-operative ACTH assays in predicting outcome, we have studied fifteen cases of Cushing's disease treated by bilateral adrenalectomy and pituitary irradiation [21].
• Following insertion of ventriculo-peritoneal shunts and external pituitary irradiation there was no change in the elevated serum concentrations of FSH, and alpha-subunit over a four year period although she developed both ACTH and TSH deficiency [22].
• Established modalities of therapy for acromegaly (surgical adenomectomy, external beam pituitary irradiation, oral dopamine agonists, and injectable somatostatin analogues) have as their common goal the lowering of circulating growth hormone (GH) levels, with a consequent reduction in serum insulin-like growth factor I (IGF-I) [23].

References