Phosphorus-32 intracavitary irradiation of cystic craniopharyngiomas: current technique and long-term results

Does the choice of surgical approach to insert an intratumoral catheter influence the results of intratumoral cystic treatment?

BACKGROUND

In the literature, only a few articles are related to the surgical approach for insertion of an intratumoral catheter. No one has evaluated the complications related to the different surgical techniques for the treatment of pediatric cystic craniopharyngiomas.

METHODS

A cooperative, multicenter (France and Brazil) study was carried out and included 50 patients (aged between 9 months and 21 years) diagnosed as having cystic craniopharyngioma treated between 1990 and 2000. Forty-nine children were available for the final analysis. The patients were divided into 3 groups: group I, 24 children who underwent a craniotomy and catheter placement under direct vision using a surgical microscope; group II, 14 children who were submitted to a stereotactic approach for the placement of the intratumoral catheter; and group III, 11 children whose catheters were placed by a freehand approach through a burr hole.

RESULTS

Eight children (16.3%) presented complications related to the placement of the catheter, namely, misplacement or leakage. The rate of the complications did not appear to be related to one specific modality of the catheter insertion.

CONCLUSION

Intracystic antiblastic drug injection is one available option in the treatment of cystic craniopharyngiomas. Because of the toxic effect of these drugs on the brain, determination of the exact placement to avoid leakage is mandatory for correct treatment. However, the results of the present study appear to indicate an excessively high incidence of complications whichever technique is used.

Craniopharyngioma surgery

Ideal surgical treatment of craniopharyngiomas remains a major challenge for neurosurgeons. Craniopharyngiomas grow in the deep-seated hypothalamic area that is paramount for vegetative, emotional and endocrine function, and for maintaining worthwhile life. The benign histological nature of craniopharyngiomas belies their biological behavior and the propensity to recur is a major threat. Surgical treatment has to weigh the risk of hypothalamic damage against the risk of tumor recurrence or progression. Both aggressive surgery and conservative minor surgery followed by radiotherapy has been proclaimed by the proponents of different schools. During the past decade, the pendulum has swung back to surgery with the attempt at radical removal. Refined neurosurgical techniques and innovative approaches yielded improved surgical results. The contemporary neurosurgical strategy of treating craniopharyngiomas with early and late outcome data is presented. Neurosurgical therapy is only beneficial in the context of an interdisciplinary treatment concept as discussed here.

Intracystic bleomycin therapy for craniopharyngioma in children

BACKGROUND

Surgical removal and radiation therapy are associated with significant risk for morbidity in the pediatric population with craniopharyngioma. Intracystic therapies have been utilized in some centers to potentially decrease morbidity associated with cystic craniopharyngioma. The aim of the study was to review the Canadian experience with intracystic bleomycin therapy (ICB).

METHODS

All centers in the Canadian Pediatric Brain Tumor Consortium (CPBTC) were invited to participate in a retrospective review of this treatment. A questionnaire was sent to each center. The data were analyzed at British Columbia's Children's Hospital.

RESULTS

In all, 6 of 17 centers utilized ICB and submitted data. A total of 17 of 19 patients with the intention to treat received bleomycin. Twelve were treated at the time of diagnosis, and 5 at the time of recurrence. Five patients achieved a complete response, 6 achieved a partial response, and 5 achieved a minor response to bleomycin. One patient was stable for 2.8 years. At the time of last follow-up, 8 patients have not required further intervention. Complications included transient symptomatic peritumoral edema (2 patients), precocious puberty (1 patient) and panhypopituitarism (2 patients). The median follow-up was 4 years (range, 0.5-10.2 years). The median progression-free survival was 1.8 years (range, 0.3-6.1 years). One patient died of a massive infarct secondary to radiation-induced moyamoya syndrome.

CONCLUSIONS

ICB was found to be well tolerated in this group of children. ICB may be a feasible and effective therapy for certain children with craniopharyngioma. Bleomycin may delay the need for aggressive surgery or radiation therapy for several years. Prospective multiinstitutional clinical trials are required to further evaluate the feasibility, effectiveness, and dose schedules of this treatment.

Craniopharyngiomas in children

BACKGROUND

The modern era of pediatric craniopharyngioma treatment includes multiple modalities including microsurgical resection, irradiation, brachytherapy or chemotherapy. No clear consensus as to the best therapeutic approach has yet been established. The aim of this study was to describe the techniques and strategies for the treatment of pediatric craniopharyngiomas in light of a literature review with particular attention to the incidence of adverse postoperative effects.

METHODS

Twenty-seven pediatric patients (median age 9.0 years) who were surgically treated for craniopharyngiomas were evaluated. We reviewed the recent literature for clinical features of craniopharyngiomas in children, including the present cases.

RESULTS

The overall rate of radiographically complete resection of our cases was 92.6%. In the literature we reviewed, the rate of gross total resection was 33-91% (average 57.8%). According to the literature, recurrence rates range from zero to 52.8% (average 16.1%) in the gross total resection group, 51.1% in the subtotal resection without radiation therapy group, and 33.5% in the subtotal resection with radiation therapy group. In six of our most recent cases, for whom we have complete outcome analysis, radiographically complete resection is 100% with only one recurrence so far over 4 years.

CONCLUSIONS

For patients in whom early postoperative MRI reveals complete craniopharyngioma removal, a very low rate of recurrence is anticipated. In the authors' experience, radiographically total excision of even large craniopharyngiomas can be safely achieved by one or a combination of several advanced microsurgical techniques, sometimes by a staged strategy. Major morbidities can be avoided, although moderate morbidities occur and require management.

Craniopharyngiomas

Craniopharyngiomas are rare, mainly sellar/parasellar, epithelial tumors diagnosed during childhood or adult life. Histologically, two primary subtypes have been recognized (adamantinomatous and papillary) with an as yet, unclarified pathogenesis. They may present with a variety of manifestations (neurological, visual, and hypothalamo-pituitary). Despite their benign histological appearance, they often show an unpredictable growth pattern, which, combined with the lack of randomized studies, poses significant difficulties in the establishment of an optimal therapeutic protocol. This should focus on the prevention of recurrence(s), improvement of survival, reduction of the significant disease and treatment-related morbidity (endocrine, visual, hypothalamic, neurobehavioral, and cognitive), and preservation of the quality of life. Currently, surgical excision followed by external beam irradiation, in cases of residual tumor, is the main treatment option. Intracystic irradiation or bleomycin, stereotactic radiosurgery, or radiotherapy and systemic chemotherapy are alternative approaches; their place in the management plan remains to be assessed in adequately powered long-term trials. Apart from the type of treatment, the identification of clinical and imaging parameters that will predict patients with a better prognosis is difficult. The central registration of patients with these challenging tumors may provide correlates between treatments and outcomes and establish prognostic factors at the pathological or molecular level that may further guide us in the future.

Dose distribution outside of a sphere of P-32 chromic phosphorous colloid

PURPOSE

To evaluate the dose distribution outside of a cyst instilled with phosphorous-32 (P-32, an electron emitter with a short effective range of 2-8 mm and average energy of 0.69 MeV, used to treat cystic craniopharyngioma) as a function of cyst size with and without plating (migration and adhesion of P-32 to the cyst surface).

METHODS AND MATERIALS

A cystic craniopharyngioma treated with instillation of P-32 was approximated by a sphere of uniformly distributed and plated chromic P-32 colloid. The percent depth dose was calculated along a radial position vector exterior to the sphere with a three-dimensional convolution integral and a dose point kernel.

RESULTS

The percent depth dose variation of surface or volume source external to a family of spheres was plotted. Complex cyst geometry is amenable to evaluation by approximation with simple spheres. Error estimates are calculated for the dose outside of truncated sphere segments. Plating might occur and raise the dose outside the cyst by more than a factor of 5.0. This has the potential to cause damage to adjacent tissues, including the optic chiasm.

CONCLUSION

Clinicians are faced with a number of treatment options for cystic craniopharyngioma, including intracystic instillation of colloid P-32. Unfortunately, plating might occur and potentially damage adjacent normal tissues. It is recommended that the propensity for a craniopharyngioma to plate be evaluated before full treatment, especially after previous treatment.

Intracavitary therapeutic options in the management of cystic craniopharyngioma

BACKGROUND

Craniopharyngioma remains an entity of controversial management due to its critical anatomical relationships and its well-known recurrence tendency. Total resection, although desirable, is not always accomplished, and it is associated with potentially permanent endocrinological and visual deficits. Consequently, this situation has led to the development of new management strategies seeking lesser morbidity. Because a high percentage of these lesions are cystic, bleomycin and radioactive-emitting sources have been postulated as new therapeutic options with promising results.

DISCUSSION

The information known to date regarding these substances is summarized and we perform a retrospective review of the clinical trials conducted over the past 30 years with special emphasis on outcome, morbidity, and mortality. Two cases from our institution are presented as examples of multimodality management.

CONCLUSION

Overall, these newer options stand out as valid alternatives in the controversial management of these challenging tumors.

Conformal radiation therapy for childhood CNS tumors

Radiation therapy plays a central role in the management of many childhood brain tumors. By combining advances in brain tumor imaging with technology to plan and deliver radiation therapy, pediatric brain tumors can be treated with conformal radiation therapy. Through conformal radiation therapy, the radiation dose is targeted to the tumor, which can minimize the dose to normal brain structures. Therefore, by limiting the radiation dose to normal brain tissues, conformal radiation therapy offers the possibility of limiting the long-term side effects of brain irradiation.In this review, we describe different approaches to conformal radiation therapy for pediatric central nervous system tumors including: A) three-dimensional conformal radiation therapy; B) stereotactic radiation therapy with arc photons; C) intensity-modulated radiation therapy; and D) proton beam radiation therapy. We discuss the merits and limitations of these techniques and describe clinical scenarios in which conformal radiation therapy offers advantages over conventional radiation therapy for treating pediatric brain tumors.

Endoscopic approach for the treatment of relapses in cystic craniopharyngiomas

INTRODUCTION

Craniopharyngiomas are tumours of the central nervous system of dysontogenetic origin. They are most commonly localized in the sellar region and appear to originate from an embryogenetic defect of the Rathke cleft. It is universally accepted that radical surgery should be performed as first surgery because surgery after relapses usually causes more difficulty due to tighter adhesion to surrounding structures. It is essential when relapses occur to evaluate which technique to use for treatment. For this reason, any new approach is welcomed in order to have as many alternatives as possible.

MATERIAL AND METHODS

In this paper we present the treatment, with a minimum follow-up of 4 years, of 5 paediatric patients affected by cystic craniopharyngiomas who went through first traditional surgery in other institutions and suffered relapses in various anatomical structures. One had a second successful endoscopic attempt at total gross resection. In 3 cases we endoscopically implanted a stent in the cystic cavity draining the cystic liquid out from the cystic cavity of the craniopharyngioma to the sphenoid sinus in order to form an accessory sinus. In 1 case a multiphase treatment has been undertaken.

RESULTS

All patients treated using a transsphenoidal endoscopic approach are still living, without relapses and no postoperative complications. In particular, there where no episodes of vasospasm (a common complication reported in the literature when the "motor oil" comes into contact with the subarachnoid space) or infections. The patient treated using the multiphase approach recovered but suffered a recurrence 2 years later due to hypothalamic infiltration.

DISCUSSION AND CONCLUSIONS

Craniopharyngioma relapse needs different treatments. Many alternative approaches have been reported but none of them is the first choice alternative. We believe endoscopic stent placement in the cystic cavity is an alternative method for the treatment of cystic relapses.

Management of Cystic Craniopharyngiomas with Phosphorus-32 Intracavitary Irradiation

OBJECTIVE

The efficacy of stereotactic intracavitary irradiation with phosphorus-32 (32P) for patients with cystic craniopharyngiomas was assessed on the basis of patient survival, tumor control, and visual and endocrinological function before and after treatment. Limited data are available regarding long-term outcomes.

METHODS

Forty-nine patients were treated with stereotactic 32P intracavitary irradiation. Of these, 25 had had no prior treatment as the primary treatment, and 24 were treated for residual or recurrent tumor cysts. At the time of 32P intracavitary irradiation, 34 of the patients were adults, and 15 were children younger than 16 years of age. The mean cyst volume was 13 ml. The radiation dose varied from 189 to 250 Gy to the cyst wall during five half-lives of the isotope (mean, 224 Gy). The mean follow-up periods were 7 years after diagnosis and 4 years after 32P treatment.

RESULTS

The actuarial survival rates were 90% at 5 years after the diagnosis and 80% at 10 years. The actuarial tumor cyst control rates were 76% at 5 years and 70% at 10 years after the diagnosis. After treatment, 9 (23%) of 40 patients who underwent preoperative and postoperative visual testing were found to have delayed worsening in visual function, 6 as a result of tumor progression and 3 attributed to irradiation. Nineteen patients (48%) had improved visual function. Of 17 patients who had normal preoperative pituitary function or stalk effect, 12 (71%) had preserved and 5 (29%) had worsened visual function. No complications other than visual or endocrinological deterioration occurred in these patients.

CONCLUSION

For patients with cystic craniopharyngiomas, 32P intracavitary irradiation proved effective, with a low risk of complications, for the control of tumor cysts but not of solid tumor components.

Stereotactic management of craniopharyngiomas

Eleven patients with craniopharyngiomas underwent 13 stereotactic procedures (intracavitary irradiation, n = 7; radiosurgery, n = 6). Nine patients (82%) had recurrent tumors after prior surgery (median, 2 operations). The median patient age was 50 years (range, 6-63 years). At a median follow-up of 38 months (range, 24-102 months), no patient had progression of the treated tumor component. Two patients developed new cysts, so the actuarial 2- and 4-year progression-free survival rates were 91 and 73%, respectively. Visual function improved in 3 patients, remained stable in 6 patients, and worsened in 1 patient. Two patients (both without prior surgery) not having diabetes insipidus pre-operatively continued to have normal posterior pituitary function. Stereotactic techniques should be considered for patients with craniopharyngiomas, especially those who have failed prior surgical resection.

Preliminary exploration of the clinical effect of bleomycin on craniopharyngiomas

OBJECTIVE

To investigate the antitumor effect of bleomycin on craniopharyngiomas.

METHODS

A series of cystic craniopharyngiomas were randomly divided into three groups: (A) intracystic chemotherapy with bleomycin; (B) intracystic chemo-radiotherapy with bleomycin and (32)P; (C) intracystic radiotherapy with (32)P and 0.9% saline. The agents were injected into the cysts through stereotactically inserted silicone tubes. Follow-up was done for a minimum of 6 months. Outcome was based on a comparison of the volume of cysts before treatment and at follow-up. The index and lactate dehydrogenase (LD) of the cystic fluids, blood and cerebrospinal fluids and the endocrine function of these patients were determined before and after therapy.

RESULTS

19 patients finished the whole therapeutic course: 5 from group A, 9 from group B and 5 from group C. Four tumors in group A were polycystic, and the drug was selectively injected into the largest cyst. At follow-up, the volumes of the cysts in groups A and B regressed from 92 to 0%, while the drug-free cysts enlarged. In group B, 6 cysts almost disappeared and another 3 regressed from 78 to 57%. In group C, one cyst progressed and the others shrank by different degrees, but none disappeared completely or nearly. All patients in groups A and B had fever of different degrees, which resolved spontaneously in 8-24 h. The complications in group B included hyponatremia in 1 patient, and both adephagia obesity and cerebral infarction in 2 patients (1 of whom died after 6 months). Apart from the oculomotor paralysis occurring in 1 patient, the remainder of group C had no other severe complications. Blood chemistry, liver, kidney, pituitary and endocrinal functions changed little during the course in all these 19 patients. LD and its isoenzymes from the cystic fluids, CSF and serum showed no marked change after bleomycin injection.

CONCLUSION

Bleomycin injected into cysts of craniopharyngiomas causes the tumor to shrink. When (32)P is added, the therapeutic effect seems better than treatment with either (32)P or bleomycin alone. Blood chemistry, liver, kidney and endocrine functions change little irrespective of the therapy applied. However, the combination of chemotherapy and radiotherapy may severely disturb both serum electrolytes and endocrine function. LD and its isoenzymes in the cystic fluids, CSF and serum may not change after bleomycin treatment.

Radiotherapy for craniopharyngioma in children: a national audit

A survey of current radiotherapy practices in the United Kingdom for treatment of craniopharyngioma in children was undertaken in view of the need to optimize control and minimize side effects in a patient group who can expect to survive for prolonged periods after treatment. Useable replies were received from 16 practitioners. A high level of conformity was reported in some areas but practice varied considerably in others. Thus whereas 15 employed magnetic resonance imaging (MRI) alone or with computed tomography (CT) to establish the gross tumour volume (GTV), six exclusively used pre-operative and seven exclusively used post-operative studies. Twelve added a margin of 1 cm to establish the planning target volume (PTV). Nine used CT planning. Fourteen gave radiation doses of between 50 and 55 Gy, but eight different dose/fractionation combinations were used. The most favoured regime (used by six) was 50 Gy in 30 fractions. Two centres provided written information on possible side effects of treatment. We suggest that it might prove helpful if a national treatment protocol was developed.

Intraoperative MR-guided instillation of phosphorus-32 for cystic craniopharyngiomas: case report

Intraoperative magnetic resonance imaging has been applied to a number of neurosurgical disease processes since the late 1990's. The ability to visualize the operative site in near-real time has added a significant degree of safety to the treatment of lesions such as a cystic craniopharyngioma which can be located in regions of the brain where an untoward consequence can result in significant neurological morbidity. Previous surgical techniques, although often successful, did not allow the neurosurgeon to directly visualize whether the goals of surgery had been met or whether there was an inadvertent complication associated with the surgical approach until after the event had occurred. The safe and accurate instillation of radioactive phosphorus into this cystic tumor resulted in clinical improvement and the maintenance of normal pituitary function for this patient. The extreme accuracy and safety of this surgical technique is demonstrated by the imaging examples provided.

Gamma knife radiosurgery for craniopharyngiomas: longterm results in the first Swedish patients

Object. The purpose of this study was to assess the long-term treatment efficacy and morbidity of patients who undergo gamma knife radiosurgery (GKS) for craniopharyngioma.

Methods. Twenty-one consecutive Swedish patients were evaluated retrospectively: 11 children (≤ 15 years) and 10 adults. The time from diagnosis to the most recent follow-up imaging study was 6.3 to 34.3 years (mean 18.2 years, median 16.8 years). Tumor volumes and morbidity from GKS or other treatments were assessed at the time of the most recent imaging study or at the time of a subsequent new treatment. The observation period ranged from 0.5 to 29 years (mean 7.5 years, median 3.5 years). The prescription dose ranged from less than 3 Gy to 25 Gy. The mean tumor volume was 7.8 cm3 (range 0.4–33 cm3).

There were 22 tumors in 21 patients treated with GKS. Five of these tumors were reduced in size, three were unchanged, and 14 increased. Tumor progression correlated with a low dose to the tumor margin. Eleven (85%) of 13 tumors that received a dose of less than 6 Gy to the margin increased in size, whereas only three (33%) of nine tumors that received 6 Gy increased. This difference was statistically significant (p = 0.01). In five of six patients tumors that became smaller after GKS there were no recurrences within a mean follow-up period of 12 years. Nine (82%) of 11 tumors in children ultimately increased after GKS, compared with five (50%) of 10 in adults. In eight patients there was a deterioration of visual function. In all except one this could be related to a volume increase but radiation-induced damage could not be excluded as a factor in any of them. Four patients developed pituitary deficiencies.

Conclusions. Gamma knife radiosurgery is effective in controlling growth of craniopharyngiomas with a minimum dose of 6 Gy. The findings also suggest that other stereotactic techniques, such as cyst aspiration and intracystic treatment, are only of value in reducing tumor volume in preparation for safe GKS.

Fractionated stereotactic radiotherapy for craniopharyngiomas

PURPOSE

To investigate outcome and toxicity after fractionated stereotactic radiation therapy (FSRT) in patients with craniopharyngiomas.

METHODS AND MATERIALS

Twenty-six patients with craniopharyngiomas were treated with FSRT between May 1989 and February 2001. Median age was 33.5 years (range: 5-57 years). Nine patients received FSRT after surgery as primary treatment, and 17 patients were irradiated for recurrent tumor or progressive growth after initial surgery. Median target dose was 52.2 Gy (range: 50.0-57.6 Gy) with conventional fractionation. Follow-up included MRI and neurologic, ophthalmologic, and endocrinologic examinations.

RESULTS

The median follow-up was 43 months (range: 7-143 months). The actuarial local control rate and actuarial overall survival rates were 100% and 100%, respectively, at 5 years and 100% and 83%, respectively, at 10 years. Four patients showed complete response, 14 patients showed partial response, and 8 patients remained stable. In 5 patients, vision improved after radiation therapy. Acute toxicity was mild. One patient required cyst drainage 3 months after radiotherapy. Late toxicity after radiotherapy included impairment of hormone function in 3 out of 18 patients at risk. We did not observe any vision impairment, radionecrosis, or secondary malignancies.

CONCLUSIONS

FSRT is effective and safe in the treatment of cystic craniopharyngiomas. Toxicity is extremely low using this conformal technique.

External beam irradiation of craniopharyngiomas: long-term analysis of tumor control and morbidity

PURPOSE

To delineate the long-term control and morbidity with external beam radiotherapy (EBRT) of craniopharyngiomas.

METHODS AND MATERIALS

Between 1971 and 1992, 24 craniopharyngioma patients underwent EBRT at the University of Pittsburgh. Most (19 of 24) were treated within 1-3 months after subtotal resection. The other prior surgical procedures were biopsy (n = 2) and gross total resection (n = 1); 2 patients did not undergo any surgical procedure. The median follow-up was 12.1 years. The median patient age was 29 years (range 5-69). The total radiation doses varied from 36 to 70 Gy (median 59.75). The normalized total dose (NTD, biologically equivalent dose given in 2 Gy/fraction [alpha/beta ratio = 2]) varied from 28 to 83 Gy (median 55.35).

RESULTS

The actuarial survival rate at 10 and 20 years was 100% and 92.3%, respectively. The actuarial local control rate at 10 and 20 years was 89.1% and 54.0%, respectively. No local failures occurred with doses >or=60 Gy (n = 12) or NTDs >or=55 Gy. The complication-free survival rate at 10 and 20 years was 80.1% and 72.1%, respectively. No complications were noted with an NTD of <or=55 Gy. The actuarial survival free from any adverse outcome (recurrence or complication) was 70.1% and 31.8% at 10 and 20 years, respectively. The adverse outcome-free survival appeared optimized (at 73%) with an NTD of 55-63 Gy. Multivariate analysis found that tumor control correlated significantly with the total dose (p = 0.02), treatment complications with NTD (p = 0.008), and adverse outcome with hypopituitarism on presentation (p = 0.03).

CONCLUSION

We recommend treating craniopharyngioma with 1.6-1.7-Gy dose fractions to 60 Gy to optimize outcome from EBRT.

Changes in cyst volume following intraoperative MRI-guided Ommaya reservoir placement for cystic craniopharyngioma

INTRODUCTION

Intracavitary treatment of solitary cystic craniopharyngiomas with (32)P is an emerging treatment option, especially for pediatric patients. We have treated two patients with solitary cystic craniopharyngiomas using intraoperative MRI (iMRI)-guided catheter placement.

METHODS

The optical tracking system of the General Electric Signa SP iMRI system was utilized for preoperative planning and intraoperative catheter tracking during insertion. Intraoperative volumetric imaging was then used to confirm final catheter position. Patients were brought back to the iMRI suite approximately 8 weeks later and diluted gadolinium was injected with further MRI to confirm the absence of communication between the cyst lumen and surrounding CSF spaces and for volumetric analysis.

RESULTS

Intraoperative imaging illustrated deformation and changes in the cyst wall during catheter placement and cyst aspiration and confirmed final catheter placement. Images acquired 8 weeks following catheter placement prior to the instillation of (32)P showed decreases in cyst volume of 40 and 85%.

CONCLUSION

iMRI-guided catheter placement for cystic craniopharyngiomas helps to assure successful catheter placement. Significant decreases in cyst volume occur in the interval between catheter placement and (32)P administration and must be accounted for to prevent overdosing of the radioisotope.

Primum non nocere: Multimodality management strategies when multiple mass lesions strike a single patient

BACKGROUND

The management of multiple symptomatic intracranial pathological processes in a single patient presents a rare and challenging problem for the neurosurgeon and the patient. Neurosurgeons must utilize a full spectrum of neurosurgical options to achieve the best patient outcome.

CASE DESCRIPTION

We present a unique case of a 63-year-old woman who presented with a large convexity meningioma causing headaches, an acoustic neuroma causing deafness and imbalance and a suprasellar arachnoid cyst compromising the visual fields. Therapeutic intervention was staged based on the primum non nocere concept. First, the patient underwent stereotactic intracavitary cyst irradiation using colloidal 32P. Secondly, microsurgical resection of the convexity meningioma was performed. Finally, Gamma Knife radiosurgery of the acoustic neuroma was performed. One year after multimodality management, the patient was neurologically improved. There was no evidence of meningioma or cyst recurrence and the growth of the acoustic neuroma was arrested.

CONCLUSION

This case demonstrates the value of multi-modality treatment of neurosurgical pathology, utilizing minimally invasive techniques when possible.

Neurosurgical management of low- and intermediate-grade gliomas

Surgery remains an effective treatment for most histologic types of low- and intermediate-grade gliomas and is an important part of their initial management. Controversies nonetheless abound regarding the timing and goals of surgery for these gliomas. This article reviews surgical therapy of low- and intermediate-grade gliomas, paying special attention to new surgical techniques.

Neurobehavioral functioning of adults with pituitary disease

Neurobehavioral disorders are not infrequent in adults with pituitary disease. The disorders can be due to compression of brain structures important for cognitive and emotional function, effects of hormonal imbalance on sensitive structures, post-surgical disruption of connecting pathways, adverse reactions to medical therapy, and adverse delayed effects of radiation therapy. A multidisciplinary team approach to the treatment of pituitary tumors will allow for the early diagnosis of neurobehavioral disorders and the institution of pharmacologic and behavioral interventions.

Intratumoral therapy with bleomycin for cystic craniopharyngiomas in children

Surgical removal of cystic craniopharyngiomas in children is associated with significant operative morbidity and recurrence rates. The purpose of this study was to review our experience with a less invasive therapy, namely, intratumoral bleomycin, in the treatment of predominantly cystic craniopharyngiomas. All children with craniopharyngiomas treated at a tertiary care pediatric neurosurgical center since 1994, when bleomycin was first used, were reviewed retrospectively. Seven patients received intratumoral bleomycin therapy. Patients received 2-5 mg bleomycin per dose, 3 times per week, for 3-5 weeks as an initial course. Mean follow-up of these patients was 3 years. In 4 patients, treatment resulted in a significant decrease (>50%) in tumor size, which has remained stable. Two patients' tumors progressed and underwent resection, and 1 patient had surgical removal because of persistent headaches, although no growth of residual tumor had been noted. One patient developed peritumoral edema as a result of bleomycin therapy. Intratumoral bleomycin is a useful alternative therapy for cystic craniopharyngiomas, and may control tumor growth and delay potentially harmful resection and/or radiotherapy in young children.

Successful management of sellar and suprasellar arachnoid cysts with stereotactic intracavitary irradiation: an expanded report of four cases

OBJECTIVE

Sellar and suprasellar arachnoid cysts may be asymptomatic or may cause headache, optic nerve compression, endocrine dysfunction, or hydrocephalus. We propose a minimally invasive treatment strategy when intervention is indicated.

METHODS

Four patients with sellar and suprasellar arachnoid cysts presented with headache, visual compromise, and endocrine dysfunction. Two of the four patients previously had undergone unsuccessful surgical intervention. The imaging studies of two patients were diagnostic of an arachnoid cyst.

RESULTS

All four patients underwent stereotactic intracavitary radiation with cyst regression and symptomatic improvement. In each patient, the optic chiasm was decompressed successfully. There were no complications from the procedure.

CONCLUSION

Stereotactic intracavitary irradiation of arachnoid cysts proved to be safe and effective. The procedure obviated the need for open cyst fenestration or shunting.

Brachytherapy for brain tumor

Brachytherapy delivers high doses of radiation to brain tumors while sparing normal surrounding tissue. It may be used as a primary treatment, an adjuvant treatment, or as therapy for recurrence of some malignant gliomas, low-grade astrocytomas, meningiomas, metastases, and pediatric brain tumors. Each of the three principal types of brachytherapy (high dose rate, low dose rate, and intracavitary) has advantages and disadvantages. Combining brachytherapy with another modality, such as hyperthermia, may improve results. Although radiosurgery is supplanting brachytherapy for many indications, brachytherapy remains a viable option. This article discusses the radiobiology, procedures, clinical applications, and outcomes of brachytherapy in managing brain tumors.

Surgical treatment of craniopharyngiomas: experience with 168 patients

OBJECT

The goal of this study was to assess the outcome of surgical management in 168 consecutive patients harboring craniopharyngiomas treated between January 1983 and April 1997.

METHODS

In 148 patients undergoing initial (primary) surgery, the pterional approach was most frequently used (39.2%), followed by the transsphenoidal approach (23.6%). For large retrochiasmatic craniopharyngiomas, the bifrontal interhemispheric approach was used increasingly over the pterional approach and led to improved surgical results. Total tumor removal was accomplished in 45.7% of transcranial and 85.7% of transsphenoidal procedures. The main reasons for incomplete removal were attachment to and/or infiltration of the hypothalamus, major calcifications, and attachment to vascular structures. The success rate in total tumor removal was inferior in the cases of tumor recurrence. The operative mortality rate in transcranial surgery was 1.1% in primary cases and 10.5% in cases of tumor recurrence. No patient died in the group that underwent transsphenoidal surgery. The rate of recurrence-free survival after total removal was 86.9% at 5 years and 81.3% at 10 years. In contrast, the 5-year recurrence-free survival rate was only 48.8% after subtotal removal and 41.5% after partial removal. Following primary surgery, the actuarial survival rate was 92.7% at 10 years, with the best results after complete tumor removal. At last follow up, 117 (79%) of 148 patients who underwent primary surgery were independent and without impairment.

CONCLUSIONS

Total tumor removal while avoiding hazardous intraoperative manipulation provides favorable early results and a high rate of long-term control in craniopharyngiomas.

Cystic craniopharyngioma: long-term results after intracavitary irradiation with stereotactically applied colloidal beta-emitting radioactive sources

OBJECTIVE

Long-term follow-up data were analyzed to assess the value of intracavitary irradiation with stereotactically applied beta-emitting radioisotopes for the treatment of craniopharyngioma cysts.

METHODS

Sixty-two of 70 consecutive patients with predominantly cystic craniopharyngiomas were selected for retrospective analysis. Beta-Emitting isotopes were injected intracystically using a computed tomography-guided and computer-assisted three-dimensional stereotactic treatment planning and application system (cumulative dose to the inner surface of the cyst wall, 200 Gy).

RESULTS

The tumor response rate gained with yttrium-90-labeled silicate (66 of 78 cysts) or phosphorous-32-labeled chromic phosphate (8 of 78 cysts) was 79.5%. Four cysts treated with rhenium-186-labeled sulfate did not respond. Mean survival after intracavitary irradiation was 9.0 +/- 0.9 years (median follow-up, 11.9 yr). In patients with solitary cysts, the mean survival was 12.5 +/- 1.4 years (actuarial 5- and 10-yr survival rates, 80 and 64%, respectively). Six months postoperatively, visual deficits (38 of 62 patients) had improved in 23 patients and were stable in 15 patients. The side effects that occurred 6 to 12 months after treatment with yttrium-90 were complete blindness (three patients), worsening of visual field cuts (one patient), third nerve palsy (one patient), and diabetes insipidus and/or panhypopituitarism (three patients).

CONCLUSIONS

Intracavitary irradiation using yttrium-90 or phosphorous-32 is highly effective in the treatment of cystic craniopharyngiomas. If applied as initial treatment in patients with solitary cysts, it is the only required therapy over a long period.

Craniopharyngioma: improving outcome by early recognition and treatment of acute complications

PURPOSE

To assess the frequency, mode of presentation, treatment, and outcome of acute complications in patients with craniopharyngioma around the time of radiotherapy.

METHODS AND MATERIALS

A review was made of 188 patients with craniopharyngioma treated with conservative surgery and external beam radiotherapy at the Royal Marsden Hospital between 1950 and 1992.

RESULTS

Twenty six (14%) (95% confidence interval: 9-19%) patients with craniopharyngioma developed acute deterioration immediately before, during and 2 months after radiotherapy with visual deterioration (19 patients), hydrocephalus (7 patients), and global deficit (7 patients). Cystic enlargement with or without hydrocephalus was the most common cause of deterioration. No patient or disease characteristics were predictive of deterioration on univariate or multivariate analysis. Eighteen patients had surgical intervention at the time of deterioration and survived the immediate period. Six of seven patients who did not have surgical intervention died. All patients who survived the postcomplication period completed the full course of external beam radiotherapy. The 10-year progression-free survival of 162 patients without deterioration was 86%, and of 18 patients with acute deterioration who recovered after surgery, 77%.

CONCLUSION

Patients with craniopharyngioma develop acute deterioration around the time of radiotherapy owing to cystic enlargement and/or hydrocephalus which does not represent tumor progression. Early recognition and appropriate surgical treatment followed by conventional full-dose radiotherapy are associated with good long-term outcome.