Persistent or recurrent acromegaly. Long-term endocrinologic efficacy and neurologic safety of postsurgical radiation therapy

Pediatric Pituitary Adenoma: Case Series, Review of the Literature, and a Skull Base Treatment Paradigm

Background  Pediatric pituitary adenoma is a rare skull base neoplasm, accounting for 3% of all intracranial neoplasms in children and 5% of pituitary adenomas. Compared with pituitary tumors in adults, secreting tumors predominate and longer disease trajectories are expected due to the patient age resulting in a natural history and treatment paradigm that is complex and controversial. Objectives  The aims of this study were to describe a large, single-institution series of pediatric pituitary adenomas with extensive long-term follow-up and to conduct a systematic review examining outcomes after pituitary adenoma surgery in the pediatric population. Methods  The study cohort was compiled by searching institutional pathology and operative reports using diagnosis and site codes for pituitary and sellar pathology, from 1956 to 2016. Systematic review of the English language literature since 1970 was conducted using PubMed, MEDLINE, Embase, and Google Scholar. Results  Thirty-nine surgically managed pediatric pituitary adenomas were identified, including 15 prolactinomas, 14 corticotrophs, 7 somatotrophs, and 4 non-secreting adenomas. All patients underwent transsphenoidal resection (TSR) as the initial surgical treatment. Surgical cure was achieved in 18 (46%); 21 experienced recurrent/persistent disease, with secondary treatments including repeat surgery in 10, radiation in 14, adjuvant pharmacotherapy in 11, and bilateral adrenalectomy in 3. At the last follow-up (median 87 months, range 3-581), nine remained with recurrent/persistent disease (23%). Thirty-seven publications reporting surgical series of pediatric pituitary adenomas were included, containing 1,284 patients. Adrenocorticotropic hormone (ACTH)-secreting tumors were most prevalent (43%), followed by prolactin (PRL)-secreting (37%), growth hormone (GH)-secreting (12%), and nonsecreting (7%). Surgical cure was reported in 65%. Complications included pituitary insufficiency (23%), permanent visual dysfunction (6%), chronic diabetes insipidus (DI) (3%), and postoperative cerebrospinal fluid (CSF) leak (4%). Mean follow-up was 63 months (range 0-240), with recurrent/persistent disease reported in 18% at the time of last follow-up. Conclusion  Pediatric pituitary adenomas are diverse and challenging tumors with complexities far beyond those encountered in the management of routine adult pituitary disease, including nuanced decision-making, a technically demanding operative environment, high propensity for recurrence, and the potentially serious consequences of hypopituitarism with respect to fertility and growth potential in a pediatric population. Optimal treatment requires a high degree of individualization, and patients are most likely to benefit from consolidated, multidisciplinary care in highly experienced centers.

Surgical results of growth hormone-secreting pituitary adenoma

OBJECTIVE

We retrospectively analyzed the surgical outcomes of 42 patients with growth hormone (GH)-secreting pituitary adenoma to evaluate the clinical manifestations and to determine which preoperative factors that significantly influence the remission.

METHODS

Forty-two patients with GH-secreting pituitary adenoma underwent transsphenoidal surgery (TSS) between 1995 and 2007. The patient group included 23 women and 19 men, with a mean age of 40.2 (range 13-61) years, and a mean follow-up duration of 49.4 (range 3-178) months after the operation. For comparable radiological criteria, we classified parasellar growth into five grades according to the Knosp classification. We analyzed the surgical results of the patients according to the most recent stringent criteria for cure.

RESULTS

The overall rate of endocrinological remission in the group of 42 patients after primary TSS was 64% (26 of 42). The remission rate was 67% (8 of 12) for microadenoma and 60% (18 of 30) for macroadenoma. The remission rate was 30% (3 of 10) for the group with cavernous sinus invasion and 72% (23 of 32) for the group with intact cavernous sinus. Cavernous sinus invasion in Knosp grade III and IV was significantly correlated with the remission rate. There was a significant relationship between preoperative mean GH concentration and early postoperative outcome, with most patients in remission having a lower preoperative GH concentration.

CONCLUSION

TSS is thought to be an effective primary treatment for GH-secreting pituitary adenomas according to the most recent criteria of cure. Because the remission rate in cases with cavernous sinus invasion is very low, early detection of the tumor before it extends into the cavernous sinus and a long-term endocrinological and radiological follow-up are necessary in order to improve the remission rate of acromegaly.

Gamma Knife surgery for invasive pituitary macroadenoma

OBJECT

Pituitary adenomas have been treated using a variety of modalities including resection, medication, fractionated radiotherapy, and stereotactic radiosurgery. The policy has been that all adenomas should first be treated with resection to reduce the volume of the tumor. The authors' study was conducted to determine the efficacy of using Gamma Knife surgery (GKS) for pituitary adenomas invading the cavernous sinus.

METHODS

Of 397 patients with pituitary tumors who underwent GKS between October 1994 and October 2005, 68 patients had pituitary macroadenomas invading the cavernous sinus. Sixty-seven cases were available for follow up. The mean age of the patients in these cases was 42.8 years (range 14-73 years). The male/female ratio was 0.8:1. The mean adenoma volume was 9.3 cm3. A total of 24 patients had undergone craniotomies and resection, and 11 patients had undergone transsphenoidal surgery prior to GKS. The mean follow-up period was 32.8 months. Tumor control was defined as a decrease or no change in tumor volume after GKS. Endocrinological improvement was defined as a decline in hormone levels to below 50% of the pre-GKS level. Tumor control was achieved in 95.5% of the cases. Endocrinological improvement was achieved in 68% of 25 patients. One patient suffered hypopituitarism after GKS.

CONCLUSIONS

Gamma Knife surgery is a safe and effective treatment for invasive pituitary macroadenoma with few complications.

Current concepts and controversies in the management of non-functioning giant pituitary macroadenomas

Despite their histologically benign nature, giant and 'invasive' pituitary tumors are one of the most complex neurosurgical challenges. In the present article, we discuss the current approaches to the management of giant pituitary tumors. Giant non-functioning pituitary tumors are usually confined inferiorly by the sellar dura, superiorly by the elevated diaphragma sellae, and laterally by an intact medial wall of the cavernous sinus. If the anatomical extensions of the tumor are understood and a radical tumor resection is achieved, the visual and long-term outcome can be extremely rewarding. The goals of surgery are to make a pathologic diagnosis and since the majority of these tumors are endocrinologically silent, the second goal should be to decompress the neural tissue. With the increasing experience and better understanding of anatomy of these tumors, trans-sphenoidal approaches have now replaced craniotomy for the excision of these tumors.

Intensity-modulated radiotherapy for pituitary adenomas: The preliminary report of the Cleveland Clinic experience

PURPOSE

Intensity-modulated radiotherapy (IMRT) is being increasingly used for the treatment of pituitary adenomas. However, there have been few published data on the short- and long-term outcomes of this treatment. This is the initial report of the Cleveland Clinic's experience.

METHODS AND MATERIALS

Between February 1998 and December 2003, 34 patients with pituitary adenomas were treated with IMRT. A retrospective chart review was conducted for data analysis.

RESULTS

With a median follow-up of 42.5 months, the treatment has proven to be well tolerated, with performance status remaining stable in 90% of patients. Radiographic local control was 89%, and among patients with secretory tumors, 100% had a biochemical response. Only 1 patient required salvage surgery for progressive disease, giving a clinical progression free survival of 97%. The only patient who received more than 46 Gy experienced optic neuropathy 8 months after radiation. Smaller tumor volume significantly correlated with subjective improvements in nonvisual neurologic complaints (p = 0.03), and larger tumor volume significantly correlated with subjective worsening of visual symptoms (p = 0.05). New hormonal supplementation was required for 40% of patients. Younger patients were significantly more likely to require hormonal supplementation (p = 0.03).

CONCLUSIONS

Intensity-modulated radiation therapy is a safe and effective treatment for pituitary adenomas over the short term. Longer follow-up is necessary to determine if IMRT confers any advantage with respect to either tumor control or toxicity over conventional radiation modalities.

Treatment of pituitary tumors: radiation

In this paper, the role of conventional radiotherapy and radiosurgery in the management of pituitary tumors is reviewed. After a short summary of the mechanism of action of irradiation therapy and the types of different irradiation techniques, the therapeutic effects and side effects are analyzed in patients with different types of pituitary tumors, including our own experience with conventional radiotherapy and radiosurgery in patients with acromegaly. Conventional fractionated radiotherapy has long been used to control growth and/or hormonal secretion of residual or recurrent pituitary tumors. However, patient selection for conventional radiotherapy still remains a controversial issue, because a number of potentially significant side effects, including hypopituitarism and other complications, have been described. Stereotactic radiotherapy/radiosurgery methods have several potential advantages over conventional radiotherapy, including their use in patients with residual or recurrent pituitary tumors who had previously been treated by conventional radiotherapy, but long-term follow-up data with these relatively new techniques are still limited.

Stereotactic radiosurgery for pituitary tumors

Pituitary adenomas frequently pose challenging clinical problems. Stereotactic radiosurgery (SRS) is one treatment option in selected patients. The purpose of this report is to identify the advantages and disadvantages of radiosurgery in cases of pituitary tumors to assess better its role in relation to other treatment. Methods for optimizing outcome are described. The author reviews several recent series to determine rates of growth control, endocrine response, and complications. In general, growth control is excellent, complications are very low, and reduction of excessive hormone secretion is fair. Depending on the clinical situation, SRS may be the treatment of choice in selected patients.

Mortality in 154 surgically treated patients with acromegaly--a 10-year follow-up survey

To determine the effects of surgery and adjuvant therapy on the mortality rate of Japanese patients with acromegaly, 154 surgically treated patients were followed until death or December 2000. Mean follow-up period was 10.0 +/- 6.5 (SD) years. Postoperative GH levels, mean values of GH levels measured in the first postoperative month, were <2.5 ng/mL in 73 (47.4%), 2.5-5.0 ng/mL in 50 (32.5%), and >5.0 ng/mL in 31 patients (20.1%). Three of 123 patients with postoperative GH levels <5.0 ng/mL underwent a second transsphenoidal surgery (TSS), the other 120 received no further treatment. Additional treatments, including second TSS, medical treatment, and gamma-knife irradiation for residual tumor, were administered to 25 of 31 patients whose postoperative GH was >5.0 ng/mL. Among the total 154 patients surveyed, 11 (7.1%) died during the follow-up period. The standard mortality ratio (SMR) was 1.17, not different from age- and sex-matched controls. The SMR of the 72 patients with postoperative GH <2.5 ng/mL was better than that of the 51 patients whose postoperative GH was 2.5-5.0 ng/mL (1.09 vs. 1.64); however, the difference was not statistically significant. In conclusion, TSS and adequate adjuvant treatment decreased the excess mortality rate of acromegalics to nearly the same level as that of the general Japanese population.

Transsphenoidal surgery and adjuvant gamma knife treatment for growth hormone-secreting pituitary adenoma

OBJECT

The results of combined transsphenoidal surgery and adjuvant gamma knife surgery (GKS) for growth hormone (GH)-secreting adenoma were investigated using biochemical cure criteria for surgery and biological cure criteria for adjuvant GKS.

METHODS

Ninety patients (42 male and 48 female patients), ranging from 11 to 75 years of age, underwent transsphenoidal surgery for GH-secreting pituitary adenoma. Preoperative and postoperative GH and insulin-like growth factor-I levels were measured, as was the postoperative GH level after the oral glucose tolerance test. Tumor size, cavernous sinus (CS) invasion, and residual tumor were evaluated using magnetic resonance (MR) imaging. Transsphenoidal microsurgery was performed, followed by adjuvant GKS when there was persistent biochemical evidence of GH hypersecretion with residual tumor detectable in the CS on MR imaging. Patients in whom GKS was contraindicated were treated with conventional radiotherapy or by medical means.

CONCLUSIONS

The overall surgical cure rate was 57% based on recently accepted biochemical cure criteria. Patients with no CS invasion achieved a 100% cure rate, whereas patients with CS invasion achieved an 82% cure rate (14 of 17 patients) after adjuvant GKS. The combination of transsphenoidal microsurgery and adjuvant GKS is the optimal therapy for patients with GH-secreting adenoma.

Efficacy of radiotherapy in normalizing serum IGF-I, acid-labile subunit (ALS) and IGFBP-3 levels in acromegaly

OBJECTIVE

Radiotherapy (RT) has been used for many years in order to complete the cure of unsuccessfully operated acromegalic patients. Several studies have shown its efficacy in normalizing GH levels, while reports about IGF-I normalization are conflicting. Moreover, data regarding other markers of disease activity, such as IGFBP-3 and acid-labile subunit (ALS), i.e. the other two components of the circulating 150 kDa complex, are lacking.

DESIGN

Retrospective study.

PATIENTS AND MEASUREMENTS

Sixty-seven acromegalic patients (20 males and 47 females, aged 40 +/- 6 years) who underwent postoperative RT (in fractionated doses for a total of 40-75 Gy) were followed-up for 11 +/- 6 years (range: 1-26 years, median: 10 years). Serum GH and IGF-I levels off medical therapy were measured in all patients; ALS and IGFBP-3 were measured in 11 patients with normalization of IGF-I concentrations. Computed tomography or nuclear magnetic resonance imaging periodically assessed possible development of pituitary deficiency along with imaging of the hypothalamic-pituitary region.

RESULTS

Forty-one out of 67 patients (58%) achieved GH levels < 2.5 microg/l by 1-15 years after RT (mean 8 +/- 6) and 37/67 patients (55%) had normal or low IGF-I levels 1-26 years after RT (mean: 12 +/- 6), a normalization of both parameters being seen in 37 patients. GH < 2.5 microg/l and normal IGF-I levels were achieved in 17/26 (65%) patients followed-up for at least 15 years. ALS and IGFBP-3 concentrations paralleled IGF-I levels in all patients studied. With respect to secondary pituitary insufficiency, acquired ACTH deficiency was found in 25 patients, TSH deficiency in 20, gonadotropin deficiency in 23 and GH deficiency in seven. In total, two cases of meningioma and one pineal tumour, possibly related to RT, were seen 9-22 years after RT.

CONCLUSIONS

RT is an effective, although slow-acting, therapeutic tool for acromegaly, with 'safe' GH levels and normal IGF-I concentrations being achieved in 65% of patients after 15 years. IGF-I levels normalize more slowly than GH levels. Radiotherapy is able to normalize the concentration of all three components of the circulating 150 kDa complex. Checks for loss of pituitary function and appearance of second brain tumours must be carried out life-long.

Surgical treatment of clinically nonsecreting pituitary adenomas in elderly patients

OBJECTIVE

The goal of this study was to evaluate the efficacy and safety of transsphenoidal pituitary surgery for elderly patients, using improved techniques of the past decade.

METHODS

We retrospectively analyzed 32 surgically treated cases of clinically nonsecreting pituitary adenomas in patients more than 70 years of age (mean, 73.9+/-3.4 yr). These patients were identified in a review of 982 patients with pituitary adenomas who were treated at University Hospital Eppendorf, Hamburg, between January 1991 and November 1999.

RESULTS

The mean preoperative duration of symptoms was 1.9 years (2 wk to 11 yr). The chiasmatic syndrome was present for 27 patients (84.4%). All patients underwent transsphenoidal surgery. Seven patients underwent reoperations. Preoperative assessments of anterior pituitary function revealed growth hormone deficiencies for 21 of 27 patients (77.8%), thyroid insufficiencies for 10 of 30 patients (33.3%), and adrenal insufficiencies for 13 of 29 patients (44.8%). Hypogonadism and hyperprolactinemia were observed for 76.7% and 46.9% of the patients, respectively. All tumors were macroadenomas, ranging from 18 to 50 mm (average, 33.6 mm) in size, including 7 enclosed and 25 invasive adenomas. Complete microscopic tumor resection was achieved in 24 cases, and subtotal removal was performed in 8 cases. There were no severe perioperative complications. In the cases involving hyperprolactinemia, serum prolactin levels were normalized for 8 of 11 patients (72.7%). Normal thyroid function was recovered for 1 of 10 patients (10.0%) with preoperative hypothyroidism. However, growth hormone or adrenal insufficiencies persisted for all patients with preoperative insufficiencies. Visual disturbances were improved for 19 of 23 patients (82.6%). All patients recovered well after surgery, with an average hospital stay of 16.3 days. Histological and immunohistochemical studies demonstrated gonadotroph adenomas in 56.7% of cases, null-cell adenomas in 26.7%, and oncocytomas in 13.3%.

CONCLUSION

Surgical treatment of nonsecreting pituitary adenomas causing visual disturbances is standard, even for elderly patients. In this series, transsphenoidal surgery was a safe procedure, with minimal morbidity and excellent tolerance. Age alone is not a contraindication for active treatment, particularly with transsphenoidal surgery.

Transsphenoidal surgery for pituitary gigantism and galactorrhea in a 3.5 year old child

The management of pituitary macroadenomas which lead to gigantism may require multiple therapeutical approaches, including medical treatment, surgery, and radiation therapy. Transsphenoidal surgery (TSS) during early childhood that achieves total removal of a growth hormone (GH) secreting tumor is rarely reported. The surgeon is confronted with special problems regarding the infantile anatomy. In this case, a 3.5 year old child, the youngest successfully treated by TSS so far, suffered from a GH- and prolactin (PRL) secreting macroadenoma of the pituitary gland. The girl initially presented with an increasing growth rate, later with breast development, and finally, at the age of 2.8 years, with galactorrhea and secretion of blood from the nipples. Increased levels of GH [122 micrograms/l], insulin-like growth factor (IGF-1) [830 micrograms/l], insulin-like growth factor binding protein 3 (IGFBP-3) [8.6 mg/l] and PRL [590 micrograms/l] were found. MRI scans revealed a macroadenoma of 2.7 cm diameter. An eight-week trial of relatively low dose dopamine agonists led to a reduction of PRL, while the GH- and IGF-1 levels remained unchanged; the tumor showed only little shrinkage. Since there was chiasma compression, we opted for early TSS. A complete tumor removal was achieved despite the difficulties of a narrow approach. After TSS, low levels of GH, IGF-1, and PRL documented a complete tumor removal, but persistent diabetes insipidus and anterior lobe deficits resulted from surgery. In summary, if primary medical therapy alone is unable to adequately reduce hormone hypersecretion and tumor size in early childhood, TSS is recommended. Thus, radiation therapy may be reserved for surgical failure.

Pituitary adenomas: results of 684 surgically treated patients and review of the literature

BACKGROUND

The outcome of patients with pituitary adenomas who were treated surgically with or without postoperative radiotherapy was analyzed. The purpose of this study was to determine the factors that strongly influence (A) tumor control, (B) the efficacy of surgery, and (C) radiotherapy based on the hormonal activity of adenomas and its invasion characteristics.

METHODS

Between 1982-1996, 684 patients with the diagnosis of pituitary adenoma were operated on. The mean age was 38 years and the mean follow-up time was 40.5 months. A total of 516 patients who were followed for more than 1 year were studied to analyze the effect of treatment modalities and invasion characteristics on tumor control. There were 297 patients with prolactinomas, 118 patients with somatotropinomas, 45 with corticotropinomas, 17 with mixed adenomas, two with thyrotropinomas, and 205 with null cell adenomas. All patients were classified according to Hardy's modified radiological classification scheme and analyzed in invasive and noninvasive groups individually based on this classification system. In the early postoperative period, 230 of these patients were given conventional radiotherapy with a mean dose of 4400 cGy. The following factors were analyzed for prognostic significance in tumor control: the effects of surgery and radiotherapy based on tumor types and invasion characteristics, the existence of histologically proven invasion of the dura mater overlying the sellar floor, and the early results of topical bromocriptine application in macroprolactinoma patients.

RESULTS

Overall surgical complications and mortality rate were similar to those of large series reported in the literature. Except for the invasive somatotropinomas and null cell adenomas, statistical analysis demonstrated the ineffectiveness of radiotherapy on tumor control. We did not detect any positive correlation between the recurrence rate and mean recurrence time or dural invasion of the sellar floor. Topical bromocriptine application seemed to improve tumor control in 21 selected macroprolactinoma patients.

CONCLUSION

Conventional radiotherapy is not as effective as expected, considering its adverse effects. The increased side effects of radiotherapy in cases with supra-parasellar extension, especially to the optic pathway and hypothalamus, limit its benefits, which could be demonstrated only in invasive somatotropinomas and null cell adenomas. In contrast with our current beliefs, tumoral infiltration of the sellar dura mater is not a prognostic factor for recurrence and therefore should not be a criterion for radiotherapy after surgery. Topical application of bromocriptine into the sellar cavity after tumor removal seems to provide superior results compared with the conventional treatment modalities.

Radiation therapy for benign central nervous system disease

The most common indication for the use of radiation therapy in the treatment of benign central nervous system disease is for the treatment of benign brain tumors, such as meningioma, pituitary adenoma, acoustic neuroma, arteriovenous malformation, and craniopharyngioma. Other less common benign intracranial tumors treated with radiation include chordoma, pilocytic astrocytoma, pineocytoma, choroid-plexus papilloma, hemangioblastoma, and temporal bone chemodectomas. Benign conditions, such as histiocytosis X, trigeminal neuralgia, and epilepsy, are also amenable to radiation treatment. There have also been reports of radiosurgery being used for the treatment of movement disorders and psychiatric disturbances, such as obsessive-compulsive and anxiety disorders. For benign brain tumors, radiation therapy as either primary or adjuvant therapy plays an integral role in improving local control. In the treatment of trigeminal neuralgia, epilepsy, tremor, and some psychiatric disturbances, radiosurgery may help ameliorate or eliminate some symptoms. Patients with benign central nervous system disease are expected to live a long time. As such, treatment should be highly conformal and based on three-dimensional planning using magnetic resonance imaging, computed tomography, or both. It is critical that damage to normal brain be minimized.

The surgical treatment of pituitary adenomas in the eighth decade

BACKGROUND

The surgical treatment of pituitary adenomas in elderly patients (i.e., over 70 years of age) is a special problem because of the increased rate of perioperative complications and the reduced tolerance of postoperative fluid and electrolyte imbalance. Therefore, the unquestionable progress in the pharmacological and radiotherapy may not allow these patients the option of radical surgical treatment. We report our experience with the transsphenoidal procedure for pituitary adenomas in aged patients in an attempt to contribute to a better definition of the actual role of surgery.

METHODS

Transsphenoidal surgery was performed in 11 patients over 70 years of age affected by various histological types of pituitary micro- and macroadenomas, ranging from Hardy Grade I through IIIc. Special care was dedicated to the postoperative treatment, in particular to water and electrolyte balances, and to the immediate treatment of any pathological variation of these parameters.

RESULTS

We had no mortality and no postoperative adjunctive morbidity. All the patients recovered well from the operation with an average hospital stay of 20 days. The tumor removal was complete in six cases and partial in the remaining five. With an average follow-up of 2 years, we did observe only one case of symptomatic recurrence of the disease.

CONCLUSIONS

Transsphenoidal surgery in the elderly is feasible and quite safe in the hands of an experienced team, if special care is devoted to the preoperative selection of patients and to the postoperative treatment of fluid and electrolyte imbalance.

Long-term endocrinological follow-up evaluation in 115 patients who underwent transsphenoidal surgery for acromegaly

OBJECT

The results of surgical therapy for acromegaly were assessed using carefully conducted endocrinological testing in 115 patients who underwent transsphenoidal surgery from 1981 to 1995.

METHODS

Ninety-nine of the 115 patients could be contacted for follow-up review; in 57 of the patients an endocrinological assessment was performed by the authors. Biochemical cure was strictly defined as a normalization of the insulin-like growth factor(IGF)-I level (obtained in 100 patients) and/or a basal or glucose-suppressed growth hormone (GH) level of 2 ng/ml or less. The mean length of follow up from transsphenoidal surgery to laboratory testing was 5.4 years with a maximum of 15.7 years. After transsphenoidal surgery alone, 61% of the patients achieved a biochemical remission; the remission rate was 88% for patients with microadenomas and 53% for those with macroadenomas. Tumor size and preoperative GH level tended to correlate negatively with outcome of surgery. Early postoperative GH level tended to correlate with long-term outcome; in cases in which the early postoperative GH level was lower than 3 ng/ml, the chance of long-term remission was 89%. Thirty-two patients received postoperative radiotherapy: in 10 (31%) of these patients the disease is currently in remission after surgery and radiotherapy only and in three others the disease is in remission with the addition of medical therapy. The overall complication rate was 6.9% with no cerebrospinal fluid leaks, meningitis, permanent diabetes insipidus, or new hypopituitarism. The overall recurrence rate was low at 5.4%.

CONCLUSIONS

This series shows, based on IFGF-I measurements and strict GH suppression criteria to define remission, that transsphenoidal surgery provides an excellent chance for long-term cure in patients with microadenomas. Surgery alone is successful in most patients with noninvasive macroadenomas; however, most patients with invasive macroadenomas will require adjunctive therapy. Recurrences are uncommon when biochemical remission is clearly documented postoperatively.

Stereotactic radiosurgery for recurrent surgically treated acromegaly: comparison with fractionated radiotherapy

OBJECT

The authors tested the assumption that gamma knife radiosurgery is more effective than fractionated radiotherapy for the treatment of patients with acromegaly who have undergone unsuccessful resective surgery. Untreated and uncured acromegaly causes illness and death. Acromegalic patients in whom growth hormone and, particularly, insulin-like growth factor I are not normalized must undergo further treatment.

METHODS

After unsuccessful operations, 16 patients suffering from recurrent and uncured acromegaly underwent stereotactic radiosurgery (25 Gy to the tumor margin, 50 Gy maximum), the outcome of which was compared with the result obtained in 50 patients who received fractionated radiotherapy (40 Gy). The cumulative distribution functions of the two groups (Kaplan-Meier estimate) differed significantly (p < 0.0001 in the log-rank test of Mantel). The mean time to simultaneous normalization of both parameters was 1.4 years in the group treated with the gamma knife and 7.1 years in the group treated with fractionated radiotherapy.

CONCLUSIONS

The authors suggest the use of stereotactic radiosurgery as the preferred treatment for recurrent acromegaly resulting from unsuccessfully resected tumors.

Treatment results of acromegaly as analyzed by different criteria

Results of treatment of acromegaly are often incomparable due to the different criteria which have been used for defining cure or control of disease. At the present time it is widely accepted, that the main criteria of cure must be normalization of IGF-1 and a GH in the OGTT < 2 ng/ml. In this retrospective study we investigated the endocrinological results of 56 patients, who were surgically treated because of a GH-producing pituitary adenoma, by different criteria. Twelve of our patients had had additional medical treatment after surgery, two received radiotherapy. At a mean follow-up of 34 months after surgery 66% of patients had a basal GH < 5 ng/ml, 64% had a GH in the OGTT < 2 ng/ml and 73% had normalization of IGF-1. The combined criteria of OGTT < 2 ng/ml and IGF-1 normalization have been fulfilled in 59% of patients. None of these latter patients developed a clinical recurrence during the follow-up period. An optimal result (endocrinological cure, no permanent surgical complications and intact pituitary function) was achieved in 43% of patients. Although surgery was responsible for 19 new pituitary axis deficiencies (7 corticotropic axis, 8 thyrotropic axis and gonadotropic axis), 22 partial deficiencies improved to normalization after surgery (respectively 6, 3, and 13). Pre-operatively 55% of patients had no pituitary deficiency, after surgery this was 61%, leaving a net positive result of 6% less pituitary deficiencies. The authors conclude that normalization of IGF-1 combined with an OGTT < 2 ng/ml are adequate criteria for the definition of cure of acromegaly. However, the authors propose to include post-treatment hypopituitarism as an additional criterion by which treatment of acromegaly should be evaluated.

Role of radiation therapy in clinical hormonally-active pituitary adenomas

BACKGROUND AND PURPOSE

The outcome following radiation therapy (RT) of hormonally-active pituitary adenomas was assessed. The purpose of this analysis was to determine the control rate after radiation, identify any prognostic factors and evaluate the late toxicity.

MATERIALS AND METHODS

From 1972 to 1986, 145 patients received RT for hormonally-active pituitary adenomas. The median age was 39 years (range 15-76), with 81 males and 64 females. There were 52 patients with acromegaly, 64 with prolactinoma, and 29 with Cushing's disease. The median follow-up was 7.3 years. RT was given as primary treatment in 17 patients, after initial surgery in 65 patients, and as part of salvage therapy in 63 patients. The median total dose was 50 Gy (daily fraction: 2 Gy). Tumor control was defined as normalization of basal hormonal level and lack of progression of adenoma assessed by imaging studies. The following factors were analyzed for prognostic significance in tumor control: age, sex, tumor type, direction of tumor extension, radiation dose, and radiation field size.

RESULTS

The 10-year actuarial proportion of patients with persistent elevated hormone level were 61% following RT alone, and 44% with the addition of medical management. The progression-free rate was 96% at 10 years. Of the 20 deaths, three patients died with uncontrolled pituitary adenoma and three died of treatment complications. The actuarial 10-year overall and cause-specific survival rates were 86% and 97%. The actuarial rates of radiation-induced hypopituitarism were 35%, 22% and 22% at 10 years for thyroid, glucocorticoid and gonadal functions, respectively. None of the factors examined were found to be significant predictors of tumor control.

CONCLUSIONS

Post-operative external beam RT is highly effective in preventing recurrence of space-occupying effects of hormonally-active pituitary adenomas. However, long-term biochemical remission is observed only in approximately 40% of patients (at 10 years), with an additional 20% requiring medical therapy. Malignancies of the CNS can develop as an infrequent late event.

Pituitary surgery in elderly patients with acromegaly

Because of the common belief that there is an increase in surgical risk and morbidity involved in the surgical therapy of elderly patients with acromegaly, physicians tend to either neglect therapy altogether or choose radiation therapy combined with medical treatment. In consideration of the expected increasing number of elderly patients resulting from social structure change in the coming years, we decided to investigate the outcome in 15 patients with acromegaly (13 women and 2 men) older than 64 years (mean, 68.3 yr) at the time of surgery in the form of a retrospective study. Medical treatment using either dopamine agonists (9 patients) and/or octreotide (4 patients) were attempted in 11 patients. For various reasons, however, medical therapy could not be permanently continued in any of these patients. The mean preoperative growth hormone (GH)-plasma level without medical treatment was 47.4 +/- 64.2 (mean +/- standard deviation) micrograms/L. At the time of operation, 13 of 15 patients had additional diseases, which led to an increased anesthesiological risk. Transnasal tumor removal was performed without anesthesiological or surgical complications in all patients. The radicality of tumor removal was controlled intraoperatively by GH measurements in eight patients. There was no postoperative mortality or serious morbidity. Postoperative basal GH-plasma levels were normal (< 4.5 micrograms/L) in all patients. None of the 13 patients who participated in long-term follow-up examinations (mean, 4.2 yr) revealed signs of definite tumor recurrence. The mean GH-plasma level at follow-up was 1.6 +/- 0.9 (mean +/- standard deviation) micrograms/L. One patient died 2 years after the operation of causes unrelated to pituitary surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Stereotactic radiosurgery for pituitary adenomas: imaging, visual and endocrine results

To determine the endocrine, ophthalmologic, and tumor growth control responses after stereotactic radiosurgery using the gamma unit, we reviewed our experience in 35 patients with pituitary adenomas. Twenty-four females and 11 males (mean age 47 years, range 9-81 years) had radiosurgery with average follow-up of 26 months (range 6-60 months). Most patients were refractory to surgical removal. Fifteen patients had Cushing's disease. Prior transsphenoidal resection was performed in 14 patients (6 had two prior operations), fractionated radiotherapy in 3, and adrenalectomy in 2. In 11 evaluable patients, the hormone response was normalized in 8, decreased in 2 and increased in 1. Five patients remained on cortisol suppression. Of 12 patients with imaging follow-up, 4 had decreased tumor size, 6 had no change, and 2 had an increase; these 2 patients underwent subsequent surgery. Ten patients had acromegaly, and 6 had undergone prior surgery. Of 8 evaluable patients, growth hormone secretion has normalized in 3, decreased in 3, and increased in 2. Six tumors decreased in size, and 2 were unchanged. One patient had repeat resection 21 months after radiosurgery and one patient underwent repeat radiosurgery. Ten patients had non-secreting adenomas; all 10 had prior operations (1-4 operations, 6 underwent frontal craniotomy) and 5 had undergone fractionated radiotherapy. Eight patients had panhypopituitarism prior to radiosurgery. Four tumors decreased in size and 6 were without change.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of surgical treatment for growth hormone-secreting pituitary adenomas

The results of surgical therapy for acromegaly were reviewed in a series of 175 patients treated between 1972 and 1983. Patients with prior surgery or radiation therapy were excluded from the study. Postoperative radiation therapy was given to 54 patients. The criterion of achieving a postoperative basal or glucose-suppressed growth hormone level of 2 ng/ml or less was used to indicate remission. Utilizing the most recently available growth hormone determinations, 90 (51.7%) of 174 patients were in remission. The actuarial probability of remission at 1 and 5 years after surgery was 48.8% and 62.7%, respectively. Tumor size and the preoperative basal growth hormone level were correlated with outcome. Surgical excision of a pituitary adenoma is the most effective therapy currently available for acromegaly.