A Long-Term Study of the Treatment of Nelson's Syndrome With Gamma Knife Radiosurgery.

BACKGROUND: Nelson's syndrome may be a devastating complication for patients with Cushing's disease who underwent a bilateral adrenalectomy. Previous studies have demonstrated that stereotactic radiosurgery (SRS) can be used to treat patients with Nelson's syndrome. OBJECTIVE: To report a retrospective study of patients with Nelson's syndrome treated with Gamma Knife radiosurgery to evaluate the effect of SRS on endocrine remission and tumor control. METHODS: Twenty-seven patients with Nelson's syndrome treated with Gamma Knife radiosurgery after bilateral adrenalectomy were included in this study. After radiosurgery, patients were followed with serial adrenocorticotropic hormone (ACTH) levels and MRI sequences to assess for endocrine remission and tumor control. Cox proportional hazards regression analysis was used to evaluate the relationship between the time to remission and potential prognostic factors. RESULTS: In 21 patients with elevated ACTH prior to SRS and endocrine follow-up data, 14 (67%) had decreased or stable ACTH levels, and 7 achieved a normal ACTH level at a median of 115 mo (range 7-272) post-SRS. Tumor volume was stable or reduced after SRS in 92.5% of patients (25/27) with radiological follow-up. Time to remission was not significantly associated with the ACTH prior to SRS (P = .252) or with the margin dose (P = .3). However, a shorter duration between the patient's immediate prior transsphenoidal resection and SRS was significantly associated with a shorter time to remission (P = .045). CONCLUSION: This retrospective analysis suggests that SRS is an effective means of achieving endocrine remission and tumor control in patients with Nelson's syndrome.

Nelson's syndrome: single centre experience using the linear accelerator (LINAC) for stereotactic radiosurgery and fractionated stereotactic radiotherapy.

Nelson's syndrome is a unique clinical phenomenon of growth of a pituitary adenoma following bilateral adrenalectomies for the control of Cushing's disease. Primary management is surgical, with limited effective medical therapies available. We report our own institution's series of this pathology managed with radiation: prior to 1990, 12 patients were managed with conventional radiotherapy, and between 1990 and 2007, five patients underwent stereotactic radiosurgery (SRS) and two patients fractionated stereotactic radiotherapy (FSRT), both using the linear accelerator (LINAC). Tumour control was equivocal, with two of the five SRS patients having a reduction in tumour volume, one patient remaining unchanged, and two patients having an increase in volume. In the FSRT group, one patient had a decrease in tumour volume whilst the other had an increase in volume. Treatment related morbidity was low. Nelson's syndrome is a challenging clinical scenario, with a highly variable response to radiation in our series.

Possible role of a radiation-induced p53 mutation in a Nelson's syndrome patient with a fatal outcome.

Nelson's syndrome (NS) is characterized by the appearance and/or progression of ACTH-secreting pituitary macroadenomas in patients who had previously undergone bilateral adrenalectomy for the treatment of Cushing's disease. Such corticotroph macroadenomas respond poorly to currently available therapeutic options which include surgery, radiotherapy and chemotherapy. P53 protein accumulation may be detected by immunohistochemistry in pituitary corticotroph adenomas and it has been suggested that it might be causally related to tumor development. Wild type P53 protein plays an important role in the cellular response to ionizing radiation and other DNA damaging agents and is mutated in many human tumors. In this study we report an adult male patient with NS who underwent both transsphenoidal and transcranial pituitary surgeries, conventional and stereotaxic radiotherapy and brachytherapy. Despite of the efforts to control tumor mass and growth, this macroadenoma displayed relentless growth and aggressive behavior. DNA extracted from the first two surgical samples, as well as DNA from peripheral blood leukocytes disclosed normal p53 sequence. DNA extracted from tumor samples obtained at surgeries performed after pituitary irradiation carried a somatic heterozygous mutation, consisting of a deletion of four cytosines between nucleotides 12,144-12,149 in exon 4 of the p53 gene. This frameshift mutation creates a stop codon in exon 4 excluding the expression of a functional protein from the defective allele. These data demonstrate a possible association between the P53 protein loss of function induced by radiotherapy and the aggressive course of the disease in this patient.

Radiation therapy in the treatment of pituitary tumors.

The treatment of pituitary tumors has progressed into a multidisciplinary approach that involves neurosurgeons, radiation oncologists, and endocrinologists. This has allowed improved outcomes in treatment of pituitary tumors due to a combination of surgical, medical, and radiation therapies. In this study, the authors review the role of radiation therapy in the treatment of pituitary adenomas.

Difficulties in diagnosis and management of ectopic Cushing syndrome.

A 18-year-old man presented to a local hospital with muscle weakness, facial edema, and a 6 kg weight gain over 2 months. After a complete work-up, he was diagnosed with pituitary Cushing syndrome and treated with a bilateral adrenalectomy for Cushing syndrome and pituitary radiotherapy for Nelson syndrome. Twenty-five years later, his ectopic source of adrenocorticotropic hormone was revealed as a pulmonary neuroendocrine tumor, and a pulmonary resection was performed. Subsequently, a biochemical and clinical remission including hyperpigmentation was achieved.

[A patient with an ACTH-producing pituitary tumor with liver metastasis]. / Eine Patientin mit ACTH-produzierendem Hypophysentumor und Lebermetastasen.

HISTORY AND FINDINGS: A 57-year-old woman had an ACTH-producing pituitary adenoma twice resected, followed by bilateral adrenalectomy for recurrent hypercortisolism. She subsequently developed a secondary postadrenalectomy syndrome (Nelson's tumour) which required further surgery and radiotherapy. The patient now presented for elucidation of a space-occupying lesion in the liver, found incidentally on abdominal ultrasonography. INVESTIGATIONS: Immunocytochemistry of the liver biopsy revealed ACTH-producing cells that were structurally identical to the cells found in the specimen resected at the previous operation. Changes were also found in the lower thoracic vertebrae, suspicious of metastases, thus suggesting a metastasizing hypophyseal carcinoma. RESULTS AND COURSE: Resection of the primary tumour and subsequent radiotherapy had arrested the corticotropic, thyrotropic, and gonadotropic functions of the pituitary, which had been adequately treated by administration of the corresponding hormones. Ocreotide, bromocriptin or cytostatics were not given because of their reported doubtful efficacy. At the time of diagnosis of the malignancy a curative operation on the liver or palliative embolization of the liver metastases were not possible because of their number and size. The bone metastases were managed palliatively by radiotherapy. CONCLUSION: No curative treatment has been found for the 66 cases of hypophyseal carcinoma reported so far. Screening investigations in patients with operated pituitary adenoma with the aim of eliciting an early diagnosis of possible malignancy cannot, therefore, be recommended, particularly since renewed tumour growth and local invasiveness do not constitute criteria for the diagnosis of pituitary carcinoma.

Tratamiento médico de los tumores hipofisiarios productores de corticotrofina y tirotrofina / Medical treatment of adrenocorticotrophin and thyrotrophin-secreting pituitary tumors

Se analiza el estado actual del tratamiento médico de los tumores hipofisiarios productores de corticotrofina (ACTH) y tirotrofina (TSH). Se presentan las investigaciones comunicadas por diversos autores en el tratamiento de la enfermedad de Cushing y el síndrome de Nelson con moduladores de la secreción de ACTH, la bromocriptina, la ciproheptadina, la ritanserina, el ácido valproico y la somatostatina. Los resultados positivos cubren un pequeño número de casos. La primera opción de tratamiento de estos tumores es la cirugía seguida de la radioterapia. Cuando no se logra extirpar completamente los tumores, el uso de drogas que actúan inhibiendo la esteroidogénesis suprarrenal constituye una terapia paliativa. Entre estas drogas se cuentan el ketoconazol, la aminoglutetimida, la metopirona, el mitotano y el trilostan, con diversos grados de efectividad y tolerancia. Los pacientes que presentan tumores hipofisiarios productores de TSH han sido tratados con éxito con análogos de la somatostatina de acción prolongada, octreotide y lanreotide SR. Se ha logrado dramática supresión de la TSH y de la subunidad alfa, así como control del hipertiroidismo y disminución del tamaño de los tumores. Estas drogas ofrecen posibilidades de tratamiento médico para los pacientes que no logran control de su enfermedad con la cirugía

Megavoltage pituitary irradiation in the management of Cushing's disease and Nelson's syndrome: long-term follow-up.

We report the long-term follow-up of the clinical and biochemical effects of megavoltage pituitary irradiation (radiotherapy; RT), administered as primary or secondary therapy, for pituitary Cushing's disease and Nelson's syndrome in 52 patients. Irradiation was administered, from a 4-15 MeV linear accelerator, via a three-field technique (two lateral, one frontal), to a total dose of 4500 cGy (rad) in 25 fractions over 35 days. Twenty-one patients received RT as primary ablative therapy for Cushing's disease and were under follow-up 5.8 to 15.5 years later (median 9.5 years). All were initially treated with metyrapone to induce normal mean plasma cortisol levels, and all achieved clinical remission on this therapy. At latest follow-up, 12 (57%) are off all therapy, in clinical remission, with a normal mean cortisol through the day; however, only two show completely normal plasma cortisol responses to dynamic testing; four remain on medical therapy with metyrapone or op'DDD and all have required a steady dose reduction accompanied by falling plasma ACTH levels; five have required alternative therapy with bilateral adrenalectomy and/or transsphenoidal hypophysectomy. Fifteen patients received RT for Nelson's syndrome, developing after bilateral adrenalectomy, and have been followed up for 1.5 to 17.3 years (median 9.6 years). Fourteen patients showed progressive depigmentation, shrinkage of the pituitary adenoma and fall in plasma ACTH levels to 1-72% (median 16%) of the pre-RT basal value. In the remaining patient an initial fall in plasma ACTH was followed by tumour enlargement at 6 years, leading to death at 11 years after RT. Of the remaining patients, results are assessed in nine who received RT after unsuccessful transsphenoidal surgery, three after transfrontal surgery for aggressive macroadenomas, and four prophylactically after bilateral adrenalectomy. Radiotherapy remains a valuable second-line therapy for Cushing's disease and its complications.

Prognostic factors and results of radiotherapy alone in the management of pituitary adenomas.

Prognostic factors and results of therapy were analyzed in a retrospective review of 70 patients with pituitary adenomas treated with radiotherapy alone from January 1954 through December 1982 at the Radiation Oncology Center, Mallinckrodt Institute of Radiology. The 10-year overall and disease-free survival was 77.8 and 76.0%. The expected survival for an age-, sex-, and race-matched population was not significantly greater at 87.2%. The 10-year disease-free survival for the distinct tumor types was 100% for Cushing's disease, 82.3% for patients with amenorrhea/galactorrhea, 79.6% for non-functioning adenomas, 69.0% for acromegaly, and 66.7% for Nelson's syndrome. Prognostic variables analyzed were age, race, sex, tumor type, tumor extent, visual field defects at diagnosis, and volume irradiated. Only the presence of visual field defects at diagnosis conferred a poor prognosis (p less than 0.001). There was a tendency toward superior tumor control with radiation doses greater than 4500 cGy (p = 0.15). The median time to progression of disease was 4.2 years, with the last failure occurring at 12 years following the completion of radiotherapy. Severe complications were apparent in 5 patients (7.1%), including one death from central nervous system radionecrosis.

Radiotherapy of pituitary tumors.

The treatment of pituitary adenomas with conventional radiotherapy is safe and effective. Radiation controls the mass effects of large tumors in 80 to 90 per cent of patients and is especially valuable in preventing recurrence after partial resection. In acromegaly, about 80 per cent of patients are controlled; with Cushing's disease, the ultimate cure rate is from 50 to 80 per cent; the control rate for prolactin-secreting adenomas is not yet established. With appropriate radiation technique, including proper dose and daily fraction size, clinically significant complications other than hypopituitarism are rare.

Results of neurosurgical treatment by a transsphenoidal approach in 10 patients with Nelson's syndrome.

Ten patients with Nelson's syndrome, nine women and one man, aged 22 to 61 years, were treated neurosurgically by a transsphenoidal approach. In four patients, microadenomas were found, ranging in diameter from 4 to 10 mm. Microscopically, mixed adenoma was diagnosed in six cases, basophilic adenoma in three patients, and chromophobe adenoma in one patient. The presence of argyrophilic nerve fibers in the adenoma tissue was noted in one case. The time of observation after transsphenoidal surgery ranged from 6 months to 10 years. Clinical remission was achieved in eight patients; in two of them, radiation therapy was used to complement surgical treatment. In two patients, recurrence of the pituitary neoplasm was observed; anaplasia was revealed at the second operation in one of them. Radiation therapy might be a useful adjunct to neurosurgery in Nelson's syndrome, especially in patients with anaplastic adenoma.

Treatment of acromegaly, Cushing disease and Nelson syndrome.

Since 1957 we have treated more than 429 patients who had pituitary neoplasms, most of which were hormone-secreting tumors. Long-term follow-up in the large group of patients treated for acromegaly shows a median survival of better than 16 years, with improvement over time. The short-term follow-up results in patients with Cushing* disease, Nelson syndrome and chromophobe adenoma are very encouraging. To compare these excellent results with those following surgical procedures, a large study of patients followed for a long period after the operations is needed.

Nelson's syndrome and spontaneous pituitary tumor infarction.

Large, adrenocorticotrophic hormone-secreting pituitary tumors (Nelson's syndrome) developed in four of 12 patients treated with a bilateral adrenalectomy for Cushing's disease. Two of the patients with Nelson's syndrome suffered spontaneous pituitary tumor infarctions. One patient improved under close observation and subsequent radiation therapy, although she ultimately died from her locally invasive tumor. The condition of the other patient-which had stabilized-appeared to be worsened by surgical intervention. The high incidence of these tumors after bilateral adrenalectomy, their large and agressive nature, and their apparent propensity to undergo spontaneous infarction supports the position that initial therapy for Cushing's disease should be directed to the pituitary gland.

Heavy particle therapy: pituitary tumors.

Therapy with 910 MeV alpha particles provides a treatment with no mortality and an extremely low morbidity and has been highly successful in the control of pituitary hormone hypersecretion and tumor growth. It is possible to deliver radiation doses to the pituitary gland that are sufficiently high to inhibit or destroy the tumor cells that cause abnormal secretory activity without damaging the surrounding structures. The data demonstrate the effectiveness of this form of treatment in acromegaly, non-functioning pituitary tumors, prolactin secreting adenomas, Cushing's disease and Nelson's syndrome.