202 Gamma Knife Pituitary Sblation for Chronic Cancer Pain Control

INTRODUCTION Neurosurgeons are, at times, called upon to help manage cancer patients with intractable, progressive pain towards the end of life when the common treatment modalities including high dose narcotics become ineffective. Various neurosurgical interventions, either destructive or neuromodulatory in nature, can offer quality of life enhancement to palliative care. METHODS Gamma Knife radiosurgery was performed focusing on the anterior pituitary gland. RESULTS >7 patients presenting with a variety of metastatic cancer diagnoses in intractable pain were given 200gy of focused cobalt 60 energy to the anterior pituitary with significant improvements in all patients chronic, intractable pain which greatly helped their end of life experience. Patient survival time ranged from 3 months to 2 years. No patient developed pituitary insufficiency. One patient underwent autopsy histologic evaluation of the pituitary gland. No patient developed visual disturbances. CONCLUSION Pituitary ablation for metastatic bony cancer via alcohol injection has been around for years but infrequently thought of as a current treatment. Gamma Knife radiosurgery is a noninvasive method of partial pituitary ablation without signficant side effects.

Growth hormone, aging and frailty

Growth hormone and related growth factors are essential for normal childhood development, secretion rate then declining from early adulthood. Adults with growth hormone deficiency, e.g. after pituitary ablation, have many clinical features such as reduced muscle and bone mass which are also seen in healthy older people. In both cases, growth hormone treatment at least partly reverses these changes. This has led to the rather elegant notion that growth hormone decline may be responsible for age-related involution and death and raises the prospect of hormonal replacement therapy for aging and frailty.

Maintenance of complete but quantitatively reduced spermatogenesis in hypophysectomized monkeys by testosterone alone

In order to investigate whether testosterone can maintain spermatogenesis in the absence of FSH in primates, four cynomolgus monkeys were hypophysectomized and implanted with 20 5-cm-long testosteronefilled silastic capsules within 45 min of pituitary ablation. Thereafter the serum levels of testosterone were elevated about 9-fold over presurgical levels. Testicular volumes declined to 60% of presurgical values. Testicular concentrations of testosterone were 50–180% of presurgical levels. Germ cell numbers were reduced to 30–50% of presurgical values and germ cell ratios suggested that the reduced numbers of all advanced germ cells were due to a decrease in the efficiency of proliferation of B spermatogonia. A fifth monkey was left untreated following hypophysectomy. Its serum testosterone was as low as that of castrated monkeys, and the testicular volume declined to 30% of that before surgery. Primitive spermatogonia were the only germ cells present 13 weeks after surgery. Thus, in primates testosterone alone maintains the complete process of spermatogenesis, however, spermatogonial proliferation is impaired in the absence of FSH.