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

Differences in Treatment Outcomes Depending on the Adjuvant Treatment Modality in Craniopharyngioma

PURPOSE

Adjuvant treatment for craniopharyngioma after surgery is controversial. Adjuvant external beam radiation therapy (EBRT) can increase the risk of long-term sequelae. Stereotactic radiosurgery (SRS) is used to reduce treatment-related toxicity. In this study, we compared the treatment outcomes and toxicities of adjuvant therapies for craniopharyngioma.

MATERIALS AND METHODS

We analyzed patients who underwent craniopharyngioma tumor removal between 2000 and 2017. Of the 153 patients, 27 and 20 received adjuvant fractionated EBRT and SRS, respectively. We compared the local control (LC), progression-free survival (PFS), and overall survival between groups that received adjuvant fractionated EBRT, SRS, and surveillance.

RESULTS

The median follow-up period was 77.7 months. For SRS and surveillance, the 10-year LC was 57.2% and 57.4%, respectively. No local progression was observed after adjuvant fractionated EBRT. One patient in the adjuvant fractionated EBRT group died owing to glioma 94 months after receiving radiotherapy (10-year PFS: 80%). The 10-year PFS was 43.6% and 50.7% in the SRS and surveillance groups, respectively. The treatment outcomes significantly differed according to adjuvant treatment in non-gross total resection (GTR) patients. Additional treatment-related toxicity was comparable in the adjuvant fractionated EBRT and other groups.

CONCLUSION

Adjuvant fractionated EBRT could be effective in controlling local failure, especially in patients with non-GTR, while maintaining acceptable treatment-related toxicity.

55-Year Follow-Up of the First Adult Patient With Craniopharyngioma Treated With Gamma Knife Radiosurgery

In May 1968, Lars Leksell and Erik-Olof Backlund achieved a pioneering breakthrough by performing the first Gamma Knife radiosurgery (GKRS) on a craniopharyngioma (CP). Today, more than 50 years later, this patient remains under continuous monitoring, providing the longest documented follow-up of a GKRS-treated CP. This case report provides a complete record of the patient's preoperative presentation, surgical assessment, GKRS, and an extensive long-term follow-up with multiple interventions. The investigation involved analysis of archived and digitalized patient records and radiological images. The patient was a 21-year-old female who presented with amenorrhea and low levels of gonadotropins. Pneumoencephalography showed a calcified 2 × 2.5 cm mass located in the suprasellar region, indicative of a CP. Subsequent stereotactic puncture confirmed a predominantly solid nature of the CP. Given the size and composition of the tumor, the surgical team opted for GKRS. Dose planning was performed manually, with coordinates determined using Leksell's stereotactic frame. The tumor was targeted with a total dose of 50 Gy using 179 beams of 60 Co. Over the subsequent 55 years, the patient underwent radiological and clinical follow-ups. Throughout this period, 4 cystic tumor recurrences occurred and were managed by stereotactic puncture and Yttrium-90 instillation radiotherapy. The solid component remained stable without repeated GKRS. The patient suffered lateral quadrant anopsia and endocrinological deficits, necessitating pharmaceutical intervention. Despite these challenges, the patient is still living an active life at age 76 years. This case stands as historic evidence of long-term safety and efficacy of GKRS for CPs.

Craniopharyngiomas

Craniopharyngiomas are difficult to treat because of their dense adherence to surrounding structures and the frequent presence of cysts which obscure the anatomy. The introduction of endonasal endoscopic approaches has enabled microsurgery to be performed without mortality. The high recurrence rate requires other forms of treatment of which GKNS has currently been shown to be perhaps the most effective. Difficulties include poorly visualized visual pathways despite which a high degree of tumor control is achievable with surprisingly little damage to vision.

Stereotactic radiosurgery for craniopharyngiomas

BACKGROUND

The management of craniopharyngiomas is challenging, usually requiring multidisciplinary care. We evaluated the long-term clinical and radiologic outcomes of Gamma Knife radiosurgery (GKRS) for craniopharyngiomas.

METHODS

This retrospective study involved patients managed with GKRS for a craniopharyngioma during the period of 1989 to 2019. Patient clinical and radiologic data, tumor characteristics, and procedural details were analyzed.

RESULTS

Thirty-eight consecutive patients (24 males; mean patient age at GKRS = 30.82 years [SD ± 20.45 years]) were treated with GKRS for craniopharyngioma. Overall survival rates at 5 and 10 years were 84.1% and 80.1%, respectively. Progression-free survival at 5 years was 48.1%, and, at 10 years, it was 29.8%. Risk factors for post-GKRS clinical deterioration were increasing number of isocenters used (p = 0.04 (HR1.32, CI 1-1.73)), increasing margin dose [p = 0.02 (HR1.52, CI 1.31-1.84)], and maximum dose > 35 Gy [p = 0.002 (HR1.35, CI 1.11-1.63)].

CONCLUSION

Stereotactic radiosurgery (SRS) appears a safe and effective management option in selected craniopharyngioma patients. Increasing margin dose and maximum dose > 35 Gy are associated with an increased risk for post-SRS neurologic deficit. Further, well-designed studies are necessary to determine the optimal timing and SRS parameters and to identify which patients with craniopharyngioma will benefit the most from SRS.

Outcome After Resection of Craniopharyngiomas and the Important Role of Stereotactic Radiosurgery in Their Management

OBJECTIVE

Experience with management of craniopharyngiomas (CPH) was evaluated retrospectively.

METHODS

Between 1981 and 2012, 100 patients underwent removal of a CPH (the main surgical group), and an original tumor grading system was applied to these cases. The mean length of follow-up was 121 months. Additionally, 17 patients underwent removal of a CPH between 2012 and 2017 (the supplementary surgical group), and in 6 of them, CyberKnife radiosurgery was performed on a residual tumor (in 5 cases) or at the time of recurrence (in 1 case).

RESULTS

In the main surgical group, the gross total resection (GTR) rate was 81%. The early and late disease-specific postoperative mortality rates were 0% and 2%, respectively. Tumor recurrence was never noted after GTR. There was a statistically significant increase in the Karnofsky Performance Scale (KPS) score after surgery. The tumor surgical grade was inversely associated with both the pre- and postoperative KPS scores, and was lower in cases operated on via the transnasal transsphenoidal approach, but was unrelated to the GTR rate. In the supplementary surgical group, the GTR rate was 65%. CyberKnife radiosurgery consistently resulted in tumor shrinkage.

CONCLUSION

GTR is the preferred management option for CPH. The original surgical grading system developed at Tokyo Women's Medical University may be helpful for clinical decision-making. CyberKnife radiosurgery for residual and recurrent CPH is associated with high tumor response rates.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Surgical management of craniopharyngiomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section

BACKGROUND AND OBJECTIVE

Craniopharyngiomas are locally aggressive neuroepithelial tumors infiltrating nearby critical neurovascular structures. The majority of published surgical series deal with childhood-onset craniopharyngiomas, while the optimal surgical management for adult-onset tumors remains unclear. The aim of this paper is to summarize the main principles defining the surgical strategy for the management of craniopharyngiomas in adult patients through an extensive systematic literature review in order to formulate a series of recommendations.

MATERIAL AND METHODS

The MEDLINE database was systematically reviewed (January 1970-February 2019) to identify pertinent articles dealing with the surgical management of adult-onset craniopharyngiomas. A summary of literature evidence was proposed after discussion within the EANS skull base section.

RESULTS

The EANS task force formulated 13 recommendations and 4 suggestions. Treatment of these patients should be performed in tertiary referral centers. The endonasal approach is presently recommended for midline craniopharyngiomas because of the improved GTR and superior endocrinological and visual outcomes. The rate of CSF leak has strongly diminished with the use of the multilayer reconstruction technique. Transcranial approaches are recommended for tumors presenting lateral extensions or purely intraventricular. Independent of the technique, a maximal but hypothalamic-sparing resection should be performed to limit the occurrence of postoperative hypothalamic syndromes and metabolic complications. Similar principles should also be applied for tumor recurrences. Radiotherapy or intracystic agents are alternative treatments when no further surgery is possible. A multidisciplinary long-term follow-up is necessary.

Radiotherapy of Parasellar Tumours

Parasellar tumours represent a wide group of intracranial lesions, both benign and malignant. They may arise from several structures located within the parasellar area or they may infiltrate or metastasize this region. The treatment of the tumours located in these areas is challenging because of their complex anatomical location and their heterogenous histology. It often requires a multimodal approach, including surgery, radiation therapy (RT), and medical therapy. Due to the proximity of critical structures and the risks of side effects related to the procedure, a successful surgical resection is often not achievable. Thus, RT plays a crucial role in the treatment of several parasellar tumours. Conventional fractionated RT and modern radiation techniques, like stereotactic radiosurgery and proton beam RT, have become a standard management option, in particular for cases with residual or recurrent tumours after surgery and for those cases where surgery is contraindicated. This review examines the role of RT in parasellar tumours analysing several techniques, outcomes and side effects.

Twenty-three years follow-up after low-dose Gamma Knife surgery of a brainstem juvenile pilocytic astrocytoma: a case report and review of the literature

Juvenile pilocytic astrocytoma (JPA) is a World Health Organization (WHO) grade I tumor that is the commonest to occur in the 0-19 age group, with an excellent prognosis of 96% 10-year survival in pediatric patients. Complete resection is the treatment of choice for JPAs. However, this is not always feasible due to the location of certain tumors, and the management following subtotal resection is controversial. Fractionated radiotherapy, chemotherapy, radiosurgery, and observation have all been used to treat tumor remnants. We report a young patient with good tumor control 23 years following low-dose Gamma Knife surgery (GKS) of a subtotally resected brainstem JPA and recommend that GKS may be a feasible treatment option to achieve long-term tumor control when subtotal resection cannot be achieved, even if the GKS prescription dose must be significantly reduced due to large tumor volume or proximity to critical structures sensitive to radiation.

Benefits of image-guided stereotactic hypofractionated radiation therapy as adjuvant treatment of craniopharyngiomas. A review

PURPOSE

Craniopharyngiomas account for 5.6-13% of intracranial tumors in children. Despite being histologically benign, these tumors remain a major neurosurgical challenge because of the typical tight adherence to adjacent critical structures. The optimal therapeutic approach for this disease is controversial. Large cystic size and adherence to neurovascular, neuroendocrine, and optic structures without a clear line of cleavage make complete resection problematic and often hazardous. For these reasons, partial resection and adjuvant treatment play an important role. Post-operative radiation therapy (RT) following either complete or incomplete tumor removal is associated with significantly decreased recurrence rates. The aim of this review is to analyze the potential advantage of the most modern technical advancements for RT of craniopharyngiomas.

METHODS

This narrative review on the topic of craniopharyngiomas was based on published data available on PUBMED/Medline. All data concerning adjuvant or upfront radiation therapy treatment of craniopharyngioma were reviewed and summarized. A more detailed analysis of fractionated frameless steretactic radiosurgery of these tumors is provided as well.

RESULTS

We reviewed the possible improvement provided by intensity modulated beams, arc therapy, image guidance, proton radiation, and fractionated stereotactic radiosurgery. Many published findings on outcome and toxicity after RT involve the use of relatively outdated RT techniques. Technologic improvements in imaging, radiation planning, and delivery have improved the distribution of radiation doses to desired target volumes and reduced the dose to nearby critical normal tissues. Currently available techniques, providing image guidance and improved radiation doses distribution profile, have shown to maintain the efficacy of conventional techniques while significantly reducing the toxicity.

CONCLUSIONS

Image-guided radiosurgery holds the dose distributions and precision of frame-based techniques with the remarkable advantage of multiple-session treatments that are better tolerated by sensitive peritumoral structures, such as the optic pathway and hypothalamus. This, together with the comfort of a frameless technique, candidates frameless image-guided radiosurgery to be the first option for the adjuvant post-operative treatment of craniopharyngiomas in children and young adults when total resection cannot be achieved, in particular those with hypothalamic involvement, and when the residual tumor is mostly solid.

Single fraction and multisession Gamma Knife radiosurgery for craniopharyngioma

PURPOSE

The optimal management of residual or recurring craniopharyngioma is still a matter of debate even though adjuvant radiation therapy plays a crucial role. Aim of our study is to report the results of single fraction or multisession Gamma Knife radiosurgery (GKRS) in patients with craniopharyngioma.

METHODS

We included 50 consecutive patients treated from 1994 to 2016. All patients had at least one post GKRS magnetic resonance imaging reviewed at our center. Vital status of all patients was assessed at the end of 2016.

RESULTS

There were 29 males (58.0%) and 21 females (42.0%). Mean age was 41.5 ± 2.8 year. Single session GKRS was delivered in 29 patients (58.0%). The mean tumor volume was 2.15 ± 0.3 cm³ and the mean prescription dose to the tumor margin was 14.3 ± 0.3 Gy. During a mean follow-up of 74.6 ± 8.4 months, seven patients (14.0%) had recurrence of disease. The 5- and 10-year recurrence-free survivals were 90.3% (95% CI, 81.0-99.6%) and 78.4% (95% CI, 59.9-96.9%), respectively. Multisession GKRS was not less effective than single fraction GKRS. Eighteen of the 28 patients (64.3%) had a tumor volume decrease of at least 10%. No serious side effects occurred after GKRS treatment, except for one case of mild visual worsening.

CONCLUSIONS

GKRS was effective for controlling the growth of residual or recurrent craniopharyngioma. Serious side effects were uncommon. Multisession GKRS seems a very promising tool to allow performing GKRS even in patients with large residual or recurrent craniopharyngioma.

Visual outcome, endocrine function and tumor control after fractionated stereotactic radiation therapy of craniopharyngiomas in adults: findings in a prospective cohort

BACKGROUND

The purpose of this study was to examine visual outcome, endocrine function and tumor control in a prospective cohort of craniopharyngioma patients, treated with fractionated stereotactic radiation therapy (FSRT).

MATERIAL AND METHODS

Sixteen adult patients with craniopharyngiomas were eligible for analysis. They were treated with linear accelerator-based FSRT during 1999-2015. In all cases, diagnosis was confirmed by histological analysis. The prescription dose to the tumor was 54 Gy (median, range 48-54) in 1.8 or 2.0 Gy per fraction, and the maximum radiation dose to the optic nerves and chiasm was 54.2 Gy (median, range 48.6-60.0) for the cohort. Serial ophthalmological and endocrine evaluations and magnetic resonance imaging (MRI) scans were performed at regular intervals. Median follow-up was 3.3 years (range 1.1-14.1), 3.7 years (range 0.8-15.2), and 3.6 years (range 0.7-13.1) for visual outcome, endocrine function, and tumor control, respectively.

RESULTS

Visual acuity impairment was present in 10 patients (62.5%) and visual field defects were present in 12 patients (75%) before FSRT. One patient developed radiation-induced optic neuropathy at seven years after FSRT. Thirteen of 16 patients (81.3%) had pituitary deficiency before FSRT, and did not develop further pituitary deficiency after FSRT. Mean tumor volume pre-FSRT was 2.72 cm³ (range 0.20-9.90) and post-FSRT 1.2 cm³ (range 0.00-13.10). Tumor control rate was 81.3% at two, five, and 10 years after FSRT.

CONCLUSIONS

FSRT was relatively safe in this prospective cohort of craniopharyngiomas, with only one case of radiation-induced optic neuropathy and no case of new endocrinopathy. Tumor control rate was acceptable.

Paediatric brain tumours: A review of radiotherapy, state of the art and challenges for the future regarding protontherapy and carbontherapy

BACKGROUND AND PURPOSE

Brain tumours are the most frequent solid tumours in children and the most frequent radiotherapy indications in paediatrics, with frequent late effects: cognitive, osseous, visual, auditory and hormonal. A better protection of healthy tissues by improved beam ballistics, with particle therapy, is expected to decrease significantly late effects without decreasing local control and survival. This article reviews the scientific literature to advocate indications of protontherapy and carbon ion therapy for childhood central nervous system cancer, and estimate the expected therapeutic benefits.

MATERIALS AND METHODS

A systematic review was performed on paediatric brain tumour treatments using Medline (from 1966 to March of 2014). To be included, clinical trials had to meet the following criteria: age of patients 18 years or younger, treated with radiation, and report of survival. Studies were also selected according to the evidence level. A secondary search of cited references found other studies about cognitive functions, quality of life, the comparison of photon and proton dosimetry showing potential dose escalation and/or sparing of organs at risk with protontherapy; and studies on dosimetric and technical issues related to protontherapy.

RESULTS

A total of 7051 primary references published were retrieved, among which 40 clinical studies and 60 papers about quality of life, dose distribution and dosimetry were analysed, as well as the ongoing clinical trials. These papers have been summarized and reported in a specific document made available to the participants of a final 1-day workshop. Tumours of the meningeal envelop and bony cranial structures were excluded from the analysis. Protontherapy allows outstanding ballistics to target the tumour area, while substantially decreasing radiation dose to the normal tissues. There are many indications of protontherapy for paediatric brain tumours in curative intent, either for localized treatment of ependymomas, germ-cell tumours, craniopharyngiomas, low-grade gliomas; or panventricular irradiation of pure non-secreting germinoma; or craniospinal irradiation of medulloblastomas and metastatic pure germinomas. Carbon ion therapy is just emerging and may be studied for highly aggressive and radioresistant tumours, as an initial treatment for diffuse brainstem gliomas, and for relapse of high-grade gliomas.

CONCLUSION

Both protontherapy and carbon ion therapy are promising for paediatric brain tumours. The benefit of decreasing late effects without altering survival has been described for most paediatric brain tumours with protontherapy and is currently assessed in ongoing clinical trials with up-to-date proton devices. Unfortunately, in 2015, only a minority of paediatric patients in France can receive protontherapy due to the lack of equipment.

Multi-modality management of craniopharyngioma: a review of various treatments and their outcomes

Craniopharyngioma is a rare tumor that is expected to occur in ∼400 patients/year in the United States. While surgical resection is considered to be the primary treatment when a patient presents with a craniopharyngioma, only 30% of such tumors present in locations that permit complete resection. Radiotherapy has been used as both primary and adjuvant therapy in the treatment of craniopharyngiomas for over 50 years. Modern radiotherapeutic techniques, via the use of CT-based treatment planning and MRI fusion, have permitted tighter treatment volumes that allow for better tumor control while limiting complications. Modern radiotherapeutic series have shown high control rates with lower doses than traditionally used in the two-dimensional treatment era. Intracavitary radiotherapy with radio-isotopes and stereotactic radiosurgery may have a role in the treatment of recurrent cystic and solid recurrences, respectively. Recently, due to the exclusive expression of the Beta-catenin clonal mutations and the exclusive expression of BRAF V600E clonal mutations in the overwhelming majority of adamantinomatous and papillary tumors respectively, it is felt that inhibitors of each pathway may play a role in the future treatment of these rare tumors.

Gamma Knife surgery for craniopharyngioma: report on a 20-year experience

Object

Although craniopharyngiomas are benign intracranial tumors, their high recurrence rates and intimate associations with surrounding neurovascular structures make gross tumor resection challenging. Stereotactic radiosurgery has been introduced as a valuable adjuvant therapy for recurrent or residual craniopharyngiomas. However, studies with large patient populations documenting long-term survival and progression-free survival rates are rare in the literature. The current study aims to report the long-term radiosurgical results and to define the prognostic factors in a large cohort of patients with a craniopharyngioma.

Methods

A total of 137 consecutive patients who underwent 162 sessions of Gamma Knife surgery (GKS) treatments at the Taipei Veterans General Hospital between 1993 and 2012 were analyzed. The patients' median age was 30.1 years (range 1.5–84.9 years), and the median tumor volume was 5.5 ml (range 0.2–28.4 ml). There were 23 solid (16.8%), 23 cystic (16.8%), and 91 mixed solid and cystic (66.4%) craniopharyngiomas. GKS was indicated for residual or recurrent craniopharyngiomas. The median radiation dose was 12 Gy (range 9.5–16.0 Gy) at a median isodose line of 55% (range 50%–78%).

Results

At a median imaging follow-up of 45.7 months after GKS, the rates of tumor control were 72.7%, 73.9%, and 66.3% for the solid, cystic, and mixed tumors, respectively. The actuarial progression-free survival rates plotted by the Kaplan-Meier method were 70.0% and 43.8% at 5 and 10 years after radiosurgery, respectively. After repeated GKS, the actuarial progression-free survival rates were increased to 77.3% and 61.2% at 5 and 10 years, respectively. The overall survival rates were 91.5% and 83.9% at the 5- and 10-year follow-ups, respectively. Successful GKS treatment can be predicted by tumor volume (p = 0.011). Among the 137 patients who had clinical follow-up, new-onset or worsened pituitary deficiencies were detected in 11 patients (8.0%). Two patients without tumor growth had a worsened visual field, and 1 patient had a new onset of third cranial nerve palsy.

Conclusions

The current study suggests that GKS is a relatively safe modality for the treatment of recurrent or residual craniopharyngiomas, and it is associated with improved tumor control and reduced in-field recurrence rates. Acceptable rates of complications occurred.

Craniopharyngioma

This report is a review of findings on the diagnosis, treatment, clinical course, and prognosis of craniopharyngioma patients. Craniopharyngiomas are rare, partly cystic and calcified embryonic malformations of the sellar/parasellar region with low histological grade (WHO I°). A bimodal age distribution has been shown, with peak incidence rates in childhood-onset at 5-14 years and adult-onset craniopharyngioma at 50-74 years. Clinical manifestations are related to hypothalamic/pituitary deficiencies, visual impairment, and increased intracranial pressure. If the tumor is favorably localized, the therapy of choice is complete resection, with care taken to preserve optical and hypothalamic functions. In patients with unfavorable tumor localization (i.e., hypothalamic involvement), recommended therapy is a limited hypothalamus-sparing surgical strategy followed by local irradiation. Although overall survival rates are high (92%), recurrences and progressions are frequent. Irradiation has proven effective in reducing recurrences and progression, and timing of postsurgical irradiation in childhood-onset cases is currently under investigation in a randomized multinational trial (KRANIOPHARYNGEOM 2007). Anatomical involvement and/or surgical lesions of posterior hypothalamic areas can result in serious quality of life-compromising sequelae such as hypothalamic obesity, psychopathological symptoms, and/or cognitive problems. It is crucial that craniopharyngioma be managed as a frequently chronic disease, providing ongoing care of pediatric and adult patients' clinical and quality of life consequences by experienced multidisciplinary teams.

A Phase I Study of Tomotherapy in Patients With Primary Benign and Low-grade Brain Tumors: Late Toxicity and Quality of Life

OBJECTIVES

To evaluate longitudinal quality of life and late neurotoxicity (>12 mo) of tomotherapy in patients with primary benign and low-grade brain tumors.

METHODS

Between January 2006 and October 2009, 49 patients with brain tumors were treated with tomotherapy at 2 radiotherapy centers in Canada. The median age of the patients was 51.0 years (range, 21 to 74 y); there were 21 men (42.86%) and 28 women (57.14%). All 49 patients had an initial Karnofsky performance score ≥70. One patient (2.04%) received 45 Gy in 25 fractions, 27 patients (55.10%) received 50.4 Gy in 28 fractions, 15 patients (30.6%) received 54 Gy in 30 fractions, and 5 patients (10.2%) received 60 Gy in 30 fractions. A total of 47 patients were analyzed for late toxicity and outcomes.

RESULTS

Changes in the Karnofsky Performance Status of the patients did not reach statistical significance (P>0.05). The majority of the quality of life parameters that reached a statistically significant level (P<0.05) of change at 2 years were changes toward improvement (drowsiness, itchy skin, emotional functioning, fatigue, nausea, and appetite). Statistically significant (P<0.05) interval deterioration in physical, role, and social functioning was observed. Actuarial overall survival at 5 years was 91.6%; disease-free survival at 5 years was 86.6%.

CONCLUSIONS

IMRT helical tomotherapy is well tolerated, without statistically significant constitutional and late neurotoxicity up to the 2-year mark.

Radiotherapy for craniopharyngioma

Radiotherapy remains the mainstay of multidisciplinary management of patients with incompletely resected and recurrent craniopharyngioma. Advances in imaging and radiotherapy technology offer new alternatives with the principal aim of improving the accuracy of treatment and reducing the volume of normal brain receiving significant radiation doses. We review the available technologies, their technical advantages and disadvantages and the published clinical results. Fractionated high precision conformal radiotherapy with image guidance remains the gold standard; the results of single fraction treatment are disappointing and hypofractionation should be used with caution as long term results are not available. There is insufficient data on the use of protons to assess the comparative efficacy and toxicity. The precision of treatment delivery needs to be coupled with experienced infrastructure and more intensive quality assurance to ensure best treatment outcome and this should be carried out within multidisciplinary teams experienced in the management of craniopharyngioma. The advantages of the combined skills and expertise of the team members may outweigh the largely undefined clinical gain from novel radiotherapy technologies.

A systematic review of the results of surgery and radiotherapy on tumor control for pediatric craniopharyngioma

OBJECTIVE

Craniopharyngiomas are rare tumors with bimodal incidence in the pediatric and adult age groups. Treatment strategies range from aggressive resection to planned limited resection combined with adjuvant therapies. Currently there is no consensus for standard of care for pediatric craniopharyngioma.

MATERIALS AND METHODS

We performed a systematic review of the published literature on pediatric craniopharyngioma. Patients were grouped based on extent of resection into gross total resection (GTR), subtotal resection (STR), and biopsy procedures. These groups were compared with respect to tumor control. Chi square was used to compare rates of recurrence. Kaplan-Meier was used to generate progression-free survival (PFS) estimates. Cox proportional hazard modeling was used to evaluate risk of progression. Each extent of resection group was also subdivided based on adjuvant therapy and compared.

RESULTS

A total of 109 studies described extent of resection resulting in a cohort of 531 patients. Recurrence data were available for 377 patients. There was no difference in 1- or 5-year PFS between the groups who underwent GTR and STR combined with radiation (XRT; log-rank; p = 0.76; 1-year PFS 89 vs 84%; 5-year PFS 77 vs 73%, respectively). One-year PFS was 84% for STR+XRT compared to 76% for STR alone while 5-year PFS was 73% for STR+XRT compared to 43% for STR alone (log-rank; p = 0.003).

CONCLUSION

Although there are limitations of a systematic review of retrospective data, our results suggest that STR+XRT of pediatric craniopharyngioma is associated with similar rates of tumor control as GTR.

Role of gamma knife radiosurgery in multimodality management of craniopharyngioma

OBJECTIVE

This retrospective study evaluated the efficacy and safety of the use of Gamma Knife Radiosurgery (GKS) along with other surgical procedures in the management of craniopharyngioma.

METHODS

Thirty-five patients (17 children and 18 adults) with craniopharyngioma were treated with GKS between May 2008 and August 2011. The age of the patients ranged from 2 to 53 years (mean 20 years). There were 26 males and 9 females. Craniopharyngiomas were solid in 7 patients, cystic in 4, and mixed in 24. Tumor size ranged from 1 to 33.3 cm(3) (mean 12 cm(3)). The prescription dose ranged from 8 to 14 Gy (mean 11.5 Gy). Maximum dose ranged from 16 to 28 Gy (mean 23 Gy). Before GKS 11 patients underwent subtotal resection of the neoplasm, 2 - neuroendocopic fenestration of the large cystic component, and 10 - stereotactic aspiration of the neoplastic cyst content.

RESULTS

The length of follow-up period varied from 6 to 36 months (mean 22 months). The tumor response rate and control rate were 77.1 % and 88.5 %, respectively. Clinical outcome was considered excellent in 10 cases, good in 17, fair in 4, and poor in 4. No one patient with normal pituitary function before GKS developed hypopituitarism thereafter. Deterioration of the visual function after treatment was noted in one patient.

CONCLUSION

After GKS tumor control can be achieved in significant proportion of patients with craniopharyngioma. Treatment-related neurological morbidity in such cases is rare. Therefore, radiosurgery may be considered useful for management of these tumors.

Radiosurgery with photons or protons for benign and malignant tumours of the skull base: a review

Stereotactic radiosurgery (SRS) is an important treatment option for intracranial lesions. Many studies have shown the effectiveness of photon-SRS for the treatment of skull base (SB) tumours; however, limited data are available for proton-SRS.Several photon-SRS techniques, including Gamma Knife, modified linear accelerators (Linac) and CyberKnife, have been developed and several studies have compared treatment plan characteristics between protons and photons.The principles of classical radiobiology are similar for protons and photons even though they differ in terms of physical properties and interaction with matter resulting in different dose distributions.Protons have special characteristics that allow normal tissues to be spared better than with the use of photons, although their potential clinical superiority remains to be demonstrated.A critical analysis of the fundamental radiobiological principles, dosimetric characteristics, clinical results, and toxicity of proton- and photon-SRS for SB tumours is provided and discussed with an attempt of defining the advantages and limits of each radiosurgical technique.

Treatment-related morbidity and the management of pediatric craniopharyngioma: a systematic review

OBJECT

Craniopharyngiomas are benign tumors but their close anatomical relationship with critical neurological, endocrine, and vascular structures makes gross-total resection (GTR) with minimal morbidity difficult to achieve. Currently, there is controversy regarding the extent, timing, and modality of treatment for pediatric craniopharyngioma.

METHODS

The authors performed a systematic review of the published literature on pediatric craniopharyngioma to determine patterns of clinical practice and the reported outcomes of standard treatment strategies. This yielded 109 studies, which contained data describing extent of resection for a total of 531 patients. Differences in outcome were examined based upon extent of resection and choice of radiation treatment.

RESULTS

Gross-total resection was associated with increased rates of new endocrine dysfunction (OR 5.4, p < 0.001), panhypopituitarism (OR 7.8, p = 0.006), and new neurological deficits (OR 9.9, p = 0.03) compared with biopsy procedures. Subtotal resection (STR) was not associated with an increased rate of new neurological deficits. Gross-total was associated with increased rates of diabetes insipidus (OR 7.7, p = 0.05) compared with the combination of STR and radiotherapy (RT). The addition of RT to STR was associated with increased rates of panhypopituitarism (OR 9.9, p = 0.01) but otherwise similar rates of morbidities.

CONCLUSIONS

Although subject to the limitations of a literature review, this report suggests that GTR is associated with increased rates of endocrinopathies compared with STR + RT, and this should be considered when planning goals of surgery.

Results after treatment of craniopharyngiomas: further experiences with 73 patients since 1997

OBJECT

The authors report surgical and endocrinological results of a series of 73 cases of craniopharyngioma that they treated surgically since 1997 to demonstrate their change in treatment strategy and its effect on outcome compared with a previous series and results reported in the literature.

METHODS

A total of 73 patients underwent surgery for craniopharyngiomas between May 1997 and January 2005. In patients with poor clinical or neuropsychological condition, even following pretreatment, only stereotactic cyst aspiration took place (8 cases). In the remaining patients, gross-total resection (GTR) was intended and appeared to be possible. The most frequent approaches were subfrontal (27 cases) and transsphenoidal (26 cases); in some cases, a multistep approach was used. The rate of GTR, complications, and functional outcome (comparing pre- and postoperative endocrine and neuropsychological testing) were evaluated. The mean duration of follow-up was 25.2 months.

RESULTS

Gross-total resection was achieved in 88.5% of cases in which a transsphenoidal approach was used and 79.5% of those in which a transcranial approach was used (85.2% of those in which a subfrontal approach was used and 72.7% of those in which a frontolateral approach was used). In the total series, GTR was achieved in 83.1% of cases (vs 49.3% in the authors' former series). The complication rate was 13.8% without any mortality. New endocrine deficits were observed more frequently in patients treated with transcranial approaches over the years (16.3%-66.7% vs 2.6%-50.0%) but were less frequent after transsphenoidal approaches (5.2%-19.2% vs 2.9%-45.7%).

CONCLUSIONS

Open surgery with intended total resection remains the treatment of choice in most patients. Initial stereotactic cyst aspiration or medical pretreatment to improve the patients' condition and adequate choice of surgical approach(es) are essential to achieve that goal. Nevertheless, a moderate increase in endocrinological deficits has to be accepted. The authors recommend using radiotherapy only in cases in which there are tumor remnants or disease progression after surgery.

Single and hypofractionated stereotactic radiotherapy with CyberKnife for craniopharyngioma

Craniopharyngiomas are slow-growing tumors found in the suprasellar region, with especially high incidence in Japanese children. Due to the location, proximity and adhesiveness of the tumor to adjacent critical structures, these tumors remain a significant clinical challenge. The purpose of this study was to evaluate the clinical outcome of single and hypofractionated stereotactic radiotherapy (SRT) with CyberKnife for craniopharyngioma. Forty-three patients (21 men and 22 women; median age 44 years; range 3-85 years) were treated at two institutions. Three cases were treated in a single fraction to a marginal dose of 13-16 Gy. The other 40 cases were treated in 2-5 fractions to a marginal dose of 13-25 Gy. Tumor volumes ranged from 0.09 to 20.8 cm(3) (median 2.0 cm(3)). Toxicities were evaluated with the Common Terminology Criteria for Adverse Events version 4.0. The median follow-up period was 40 months (range 12-92 months). The 3-year overall survival and local control rates were 100 and 85%, respectively. In-field cyst enlargement was observed in 9 patients. These tumors had significantly larger volumes (mean 6.9 cm(3); 95% confidence interval, CI, 2.8-10.9 cm(3)) than the 34 controlled tumors (2.9 cm(3); CI 1.5-4.3 cm(3)) (P = 0.02). Out-field tumor regrowth was observed in 4 patients. No radiation-induced symptomatic visual disorder or brain necrosis was observed. Hypopituitarism was observed in only 1 patient. Single and hypofractionated SRT using CyberKnife produced high tumor control rates with minimal complications. Hypofractionated SRT may be useful for protecting the visual nerve and neuroendocrine function, especially for tumors located near the optic pathways and for large tumors.

Management of recurrent craniopharyngioma

Craniopharyngioma accounts for approximately 1.2% to 4.6% of all intracranial tumours. Their close proximity to vital structures such as the hypothalamic-pituitary axis and optic apparatus makes them one of the most challenging and controversial management dilemmas in neurosurgery. Recurrence following initial transcranial resection is reported as 9% to 51% at a median time of 26 months to 96 months. Treatment options for recurrent craniopharyngioma include repeat surgery, radiotherapy, radiosurgery and intracystic therapies. We present a series of 54 recurrent craniopharyngiomas treated at The Royal Melbourne Hospital between 1991 and 2008 and discuss the management options now available.

Endocrinologic, neurologic, and visual morbidity after treatment for craniopharyngioma

Craniopharyngiomas are locally aggressive tumors which typically are focused in the sellar and suprasellar region near a number of critical neural and vascular structures mediating endocrinologic, behavioral, and visual functions. The present study aims to summarize and compare the published literature regarding morbidity resulting from treatment of craniopharyngioma. We performed a comprehensive search of the published English language literature to identify studies publishing outcome data of patients undergoing surgery for craniopharyngioma. Comparisons of the rates of endocrine, vascular, neurological, and visual complications were performed using Pearson's chi-squared test, and covariates of interest were fitted into a multivariate logistic regression model. In our data set, 540 patients underwent surgical resection of their tumor. 138 patients received biopsy alone followed by some form of radiotherapy. Mean overall follow-up for all patients in these studies was 54 ± 1.8 months. The overall rate of new endocrinopathy for all patients undergoing surgical resection of their mass was 37% (95% CI = 33-41). Patients receiving GTR had over 2.5 times the rate of developing at least one endocrinopathy compared to patients receiving STR alone or STR + XRT (52 vs. 19 vs. 20%, χ(2) P < 0.00001). On multivariate analysis, GTR conferred a significant increase in the risk of endocrinopathy compared to STR + XRT (OR = 3.45, 95% CI = 2.05-5.81, P < 0.00001), after controlling for study size and the presence of significant hypothalamic involvement. There was a statistical trend towards worse visual outcomes in patients receiving XRT after STR compared to GTR or STR alone (GTR = 3.5% vs. STR 2.1% vs. STR + XRT 6.4%, P = 0.11). Given the difficulty in obtaining class 1 data regarding the treatment of this tumor, this study can serve as an estimate of expected outcomes for these patients, and guide decision making until these data are available.

Phosphorus-32 therapy for cystic craniopharyngiomas

BACKGROUND AND PURPOSE

To examine control rates for predominantly cystic craniopharyngiomas treated with intracavitary phosphorus-32 (P-32).

MATERIAL AND METHODS

22 patients with predominantly cystic craniopharyngiomas were treated at Indiana University between October 1997 and December 2006. Nineteen patients with follow-up of at least 6 months were evaluated. The median patient age was 11 years, median cyst volume was 9 ml, a median dose of 300 Gy was prescribed to the cyst wall, and median follow-up was 62 months.

RESULTS

Overall cyst control rate after the initial P-32 treatment was 67%. Complete tumor control after P-32 was 42%. Kaplan-Meier 1-, 3-, and 5-year initial freedom-from-progression rates were 68%, 49%, and 31%, respectively. Following salvage therapy, the Kaplan-Meier 1-, 3-, and 5-year ultimate freedom-from-progression rates were 95%, 95%, and 86%, respectively. All patients were alive at the last follow-up. Visual function was stable or improved in 81% when compared prior to P-32 therapy. Pituitary function remained stable in 74% of patients following P-32 therapy.

CONCLUSIONS

Intracystic P-32 can be an effective and tolerable treatment for controlling cystic components of craniopharyngiomas as a primary treatment or after prior therapies, but frequently allows for progression of solid tumor components. Disease progression in the form of solid tumor progression, re-accumulation of cystic fluid, or development of new cysts may require further radiotherapy or surgical intervention for optimal long-term disease control.

The role of radiosurgery in the treatment of craniopharyngiomas

The treatment of craniopharyngiomas is composed of an intricate balance of multiple modalities. Resection and radiotherapy have been combined to synergistically control tumor growth while preventing undue harm to crucial neurovascular structures. Although a craniopharyngioma is a benign lesion pathologically, it may induce severe neurological injury due to its location and rate of growth. More recently, the advent of targeted, fractionated radiotherapy has allowed for more aggressive tumor control while reducing the necessity for large resections. Initial studies have demonstrated significant tumor control in patients who are treated with resection combined with radiation therapy, versus surgery alone, with a lower rate of treatment-associated neurological deficits. In this review, a detailed account of the current studies evaluating the role of stereotactic radiosurgery in the management of craniopharyngiomas is presented. The authors also provide a short account of their experience to aid in defining the role of CyberKnife radiosurgery.

Craniopharyngioma: a comparison of tumor control with various treatment strategies

OBJECT

Craniopharyngiomas have a propensity to recur after resection, potentially causing death through their aggressive local behavior in their critical site of origin. Recent data suggest that subtotal resection (STR) followed by adjuvant radiotherapy (XRT) may be an appealing substitute for gross-total resection (GTR), providing similar rates of tumor control without the morbidity associated with aggressive resection. Here, the authors summarize the published literature regarding rates of tumor control with various treatment modalities for craniopharyngiomas.

METHODS

The authors performed a comprehensive search of the English language literature to identify studies publishing outcome data on patients undergoing surgery for craniopharyngioma. Rates of progression-free survival (PFS) and overall survival (OS) were determined through Kaplan-Meier analysis.

RESULTS

There were 442 patients who underwent tumor resection. Among these patients, GTR was achieved in 256 cases (58%), STR in 101 cases (23%), and STR+XRT in 85 cases (19%). The 2- and 5-year PFS rates for the GTR group versus the STR+XRT group were 88 versus 91%, and 67 versus 69%, respectively. The 5- and 10-year OS rates for the GTR group versus the STR+XRT group were 98 versus 99%, and 98 versus 95%, respectively. There was no significant difference in PFS (log-rank test) or OS with GTR (log-rank test).

CONCLUSIONS

Given the relative rarity of craniopharyngioma, this study provides estimates of outcome for a variety of treatment combinations, as not all treatments are an option for all patients with these tumors.

Tolerance of the optic apparatus in single-fraction irradiation using stereotactic radiosurgery: evaluation in 100 patients with craniopharyngioma

OBJECTIVE

To determine the limiting dose to the optic apparatus in single-fraction irradiation in patients with craniopharyngioma treated with gamma knife radiosurgery (GKRS).

METHODS

One hundred patients with 109 craniopharyngiomas treated with GKRS were evaluated with a median follow-up period of 68 months. Tumor volume varied from 0.1 to 36.0 (median, 3.3) cm. Marginal doses varied from 10 to 18 (median, 11.4) Gy. Maximum dose to any part of the optic apparatus varied from 2 to 18 (median, 10) Gy.

RESULTS

The actuarial 5- and 10-year overall rates of survival of tumor progression after GKRS were 93% and 88%, respectively. Similarly, the actuarial 5- and 10-year progression-free survival rates were 62% and 52%, respectively. Among 94 patients in whom visual function was evaluable after GKRS, only 3 patients developed radiation-induced optic neuropathy, indicating an overall Kaplan-Meier radiation-induced optic neuropathy rate of 5%. Of these patients, 2 received 15 Gy or greater to the optic apparatus. Another patient who received 8 Gy or less had undergone previous fractionated radiation therapy with a biologically effective dose of 60 Gy.

CONCLUSION

The optic apparatus seems to be more tolerant of irradiation than previously thought. Careful dose planning is essential, particularly in patients who underwent prior external beam radiation therapy.

Cystic craniopharyngioma: trans-sphenoidal surgery and intra-cystic apposition of "bleomycin wax"

BACKGROUND

The current therapeutic approach to craniopharyngioma is multidisciplinary. Sub-total removal, followed by adjuvant treatments, especially in large cystic tumours, is an accepted regime reported by many authors.

CASE REPORT

A young patient with an intra- and suprasellar cystic craniopharyngioma was operated on via a microsurgical trans-sphenoidal approach, achieving sub-total removal and bleomycin mixed with bone wax ("bleomycin wax") applied to the capsular remnant.

RESULTS

Pre-operative neurological and endocrinological deficit improved after surgery. There was no evidence of tumour recurrence after a follow-up period of 5.4 years.

CONCLUSIONS

The intra-operative use of "bleomycin-wax" should be limited to those patients in whom intra-operative CSF fistula does not occur.

Computer aided robotic radiosurgery

Radiosurgery involves the precise delivery of sharply collimated high-energy beams of radiation to a distinct target volume along selected trajectories. Historically, accurate targeting required the application of a stereotactic frame, thus limiting the use of this procedure to single treatments of selected intracranial lesions. However, the scope of radiosurgery has undergone a remarkable broadening since the introduction of image-guided robotic radiosurgery. Recent developments in real-time image guidance provide an effective frameless alternative to conventional radiosurgery and allow both the treatment of lesions outside the skull and the possibility of performing hypofractionation. As a consequence, targets in the spine, chest and abdomen can now also be radiosurgically ablated with submillimetric precision. Meanwhile, the combination of image guidance, robotic beam delivery, and non-isocentric inverse planning can greatly enhance the conformality and homogeneity of radiosurgery. The aim of this article is to describe the technological basis of image-guided radiosurgery and provide a perspective on future developments. The current clinical usage of robotic radiosurgery will be reviewed with an emphasis on those applications that may represent a major shift in the therapeutic paradigm.

Radiosurgery for craniopharyngioma

PURPOSE

To analyze the outcomes of gamma knife stereotactic radiosurgery (SRS) for residual or recurrent craniopharyngiomas and evaluate the factors that optimized the tumor control rates.

METHODS AND MATERIALS

A total of 46 patients with craniopharyngiomas underwent 51 SRS procedures at University of Pittsburgh between 1988 and 2007. The median tumor volume was 1.0 cm(3) (range, 0.07-8.0). The median prescription dose delivered to the tumor margin was 13.0 Gy (range, 9-20). The median maximal dose was 26.0 Gy (range, 20-50). The mean follow-up time was 62.2 months (range, 12-232).

RESULTS

The overall survival rate after SRS was 97.1% at 5 years. The 3- and 5-year progression-free survival rates (solid tumor control) were both 91.6%. The overall local control rate (for both solid tumor and cyst control) was 91%, 81%, and 68% at 1, 3, and 5 years, respectively. No patients with normal pituitary function developed hypopopituitarism after SRS. Two patients developed homonymous hemianopsia owing to tumor progression after SRS. Among the factors examined, complete radiosurgical coverage was a significant favorable prognostic factor.

CONCLUSION

SRS is a safe and effective minimally invasive option for the management of residual or recurrent craniopharyngiomas. Complete radiosurgical coverage of the tumor was associated with better tumor control.

Surgical management of craniopharyngiomas

Surgical treatment of craniopharyngiomas has been historically challenging and, despite advancements in microsurgical and skull base techniques, continues to pose a challenge to modern day surgeons. In particular, proponents of subtotal resection in conjunction with radiotherapy argue that this less aggressive approach can yield equivalent control rates with lower morbidity, while others argue that gross total resection is superior. Regardless of whether gross total or subtotal resection is the goal, surgical planning must include a thorough endocrine and neuro-ophthalmologic evaluation as well as imaging, and the approach, whether transsphenoidal or transcranial, must take into account the nature of the tumor and its location. In addition, optimal management of craniopharyngiomas must consist of an individualized and multidisciplinary approach not only including neurological surgery, but also including endocrinology, neuro-ophthalmology, neuropsychology, and, often, radiation-oncology.

Craniopharyngioma: historical notes

For centuries tumors have been described which today with some confidence can be diagnosed as craniopharyngiomas. It was not until 1904 Erdheim described what he called 'hypophysial duct tumors', and which Cushing later gave the name craniopharyngioma. The first operation for this neoplasm took place in 1909. It soon became evident that the outcome of surgery was rather dismal with high mortality and morbidity rates-even after corticosteroid therapy became available around 1950. Radiotherapy was introduced and later refined as radiosurgery. This paper presents a short survey of the accumulation of knowledge of craniopharyngiomas.

Surgical management of giant craniopharyngiomas

INTRODUCTION

Multimodal treatment in the management of giant craniopharyngiomas (>4 cm in diameter) is necessary to obtain optimal results, and includes conservative or palliative treatment and "aggressive" removal. The significance of a new treatment algorithm including direct surgical resection with the intent to avoid radiation therapy and regrowth will be discussed here.

MATERIALS AND METHODS

Between January 1996 and January 2005 16 patients were diagnosed with giant craniopharyngiomas. Two of them underwent only cyst aspiration because of their advanced age and/or lack of improvement of neuropsychological deficits. One patient underwent transsphenoidal operation and in the remaining 13 transcranial surgery was performed. Four additional patients underwent surgery for recurrence. The prospective protocol included pre- and post-operative dynamic endocrine tests, high field 1.5 T MRI and ophthalmological as well as neuropsychological examinations.

RESULTS

In resectable tumours, the rate of total removal was ten out of 12 with two recurrences. In the remaining two patients with recurrences this intention was abandoned because of a firm tumour or a deteriorating neuropsychological status prior to the scheduled additional operation. There was no mortality and the morbidity rate was 6.3%. Visual function improved in 11, was unchanged in one and deteriorated in two patients. Secretion of different adenohypophyseal hormones deteriorated after tumour resection in one to three patients, and new diabetes insipidus occurred in six patients. There was no permanent deterioration of neuropsychological function.

CONCLUSION

Special reference is given to direct resection of tumours at an optimal timing within this management. If hypothalamic disturbances are absent or improving due to pre-treatment (medical therapy, symptomatic surgery), giant craniopharyngiomas can be surgically removed in more than two of three patients with low morbidity and only moderate deterioration of endocrine function. The latter has to be accepted when curative surgery is intended, but even then, recurrences cannot be prevented. Contraindication for curative surgery is persisting hypothalamic damage necessitating conservative treatment modalities.

Radiation therapy and CyberKnife radiosurgery in the management of craniopharyngiomas

OBJECT

Many benign intracranial tumors are amenable to radiotherapy treatment including meningiomas, schwannomas, pituitary tumors, and craniopharyngiomas. The authors present their experience in the treatment of craniopharyngiomas in 16 patients using frameless CyberKnife stereotactic radiosurgery (SRS). The authors discuss the role of radiation therapy in the management of these tumors, and more specifically, the role of CyberKnife SRS.

METHODS

Sixteen patients were treated for residual or recurrent craniopharyngioma between 2000 and 2007 with CyberKnife SRS at Stanford University Medical Center. All patients underwent magnetic resonance imaging and visual and neuroendocrine evaluations before and at regular intervals after SRS. A multisession treatment regimen and a nonisocentric treatment plan for each patient were used with a mean marginal dose of 21.6 Gy and a mean maximal dose of 29.9 Gy.

RESULTS

There were adequate clinical data to assess outcomes in 11 of 16 patients. Evaluation of patients between 13 and 71 years of age (mean 34.5 years) with a mean follow-up period of 15.4 months revealed no deterioration in visual or neuroendocrine function. Tumor shrinkage was achieved in 7 of these 11 patients, and tumor control in another 3. One patient had cystic enlargement of the residual tumor.

CONCLUSIONS

The authors' early experience with the application of CyberKnife SRS to residual or recurrent craniopharyngiomas has been positive; control or shrinkage of the tumor was achieved in 91% of patients, with no visual or neuroendocrine complications. Longer-term follow-up with a larger group of patients is required to fully evaluate the safety and effectiveness of this treatment modality.

Evaluation of the role of Gamma Knife surgery in the treatment of craniopharyngiomas

✓ The management of craniopharyngioma involves balancing adequate reduction in tumor volume and prevention of recurrence while minimizing damage to delicate surrounding structures. Because of the lesion's proximity to the optic chiasm and its relationship to the hypothalamic–pituitary axis, morbidity rates following treatment can be high. Gamma Knife surgery (GKS) is now being considered as a viable method of providing tumor control while ensuring minimal side effects. The authors conducted a literature review of 10 studies in which GKS was used to treat craniopharyngioma; some lesions had been previously treated and some had not. The mean marginal dose ranged from 5 to 16.4 Gy (mean 12.3 Gy). Tumor control was achieved in 75% of cases overall and varied with tumor subtype (cystic, solid, mixed). Control was seen in 90% of solid, 80% of cystic, and 59% of mixed tumors. The overall morbidity rate resulting from radiosurgery was 4% and the overall mortality rate was 0.5%. These results suggest that GKS may provide a favorable benefit-to-risk profile for many patients with craniopharyngiomas.

Role of stereotactic radiosurgery and fractionated stereotactic radiotherapy in pediatric brain tumors

Brain tumors are the most common solid tumor in childhood. Surgery and/or fractionated radiotherapy are conventional treatment modalities. Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) are advanced radiation therapy techniques that have been frequently used in adults with brain tumors but they are less frequently used in pediatric patients. SRS and FSRT can potentially add to the armamentarium against brain tumors in children. This article will review the role of SRS and FSRT in the management of pediatric brain tumors.

[Craniopharyngiomas]

Craniopharyngiomas are rare benign epithelial tumors, arising from the pituitary stalk or gland and developing in the sellar and suprasellar region, affecting both adults and children. Incidence is 0.5 to 2 new cases per million inhabitants. Clinical features essentially include visual disturbances, endocrine deficiencies, and neurological signs. Initial signs are often visual loss and increased intracranial pressure in children, growth and pubertal delay in teenagers, visual disturbances or cognitive impairment in adults. Diagnosis is made on MRI and CT scan, demonstrating a sellar or suprasellar tumor, heterogeneous, with frequent calcifications. Craniopharyngiomas can be classified depending on their locations from the sella, the diaphragma sellae, and upon their origins from the pituitary stalk or the infundibulum. They can also be classified depending on the location from the optic chiasm and the third ventricle. This classification allows surgical series comparison, which is of importance since developments and extensions of the tumor can explain surgical difficulties. The management of this lesion is still controversial. Because it is an extra-cerebral benign lesion, the ideal goal of treatment should be complete tumor removal with improvement of altered visual functions, minimal deterioration of endocrine function, and no neuropsychological impairment. But the situation of the tumor, its relationship with third ventricle, hypothalamus, optic tract, vascular structures make its removal often difficult. However, great progresses have been realized in surgical treatment, resulting in a dramatic improvement of the prognosis of craniopharyngiomas. Nowadays, one can expect total removal in 60 to 70% of patients, subtotal removal in 20 to 30%, and partial removal in 10%. When total removal is impossible, radiotherapy may reduce the risk of a poor evolution. Recurrences are a problem in 15% of patients with total removal, 35% in subtotal removal, 70% in partial removal. If radiotherapy has not been performed as first treatment, it is efficient in 80% of recurrences. Long term follow up is necessary in these patients, due to medical management of endocrine, visual and psychological problems, and risk of late recurrence. With close involvement in this management, most of patients may enjoy a good outcome, 80% being able to return to normal active life.

Evaluation and management of Cushing syndrome in cases of negative sellar magnetic resonance imaging

✓ The treatment of patients with Cushing disease and without magnetic resonance (MR) imaging evidence of Cushing disease (that is, negative MR imaging) is discussed in this paper. Magnetic resonance imaging is the diagnostic modality of choice in Cushing disease, but in up to 40% of these patients negative imaging can be caused by tumor-related factors and limitations in imaging techniques. In cases in which the MR imaging is negative, it is critical to make sure that the diagnosis of Cushing disease is correct. This can be accomplished by performing a complete laboratory and imaging workup, including dexamethasone suppression tests, imaging of the adrenal glands, and inferior petrosal sinus sampling when appropriate. If these evaluations suggest a pituitary source of the hypercortisolemia, then transsphenoidal surgery remains the treatment of choice. The authors favor the endoscopic approach because it gives a wider and more magnified view of the sella and allows inspection of the medial cavernous sinus walls. Radiosurgery is an effective treatment option in patients with persistent Cushing disease. When a target cannot be found on MR imaging, one can target the entire sellar region with radiosurgery.