Radiosurgery for craniopharyngioma

Enhanced outcomes in residual or recurrent craniopharyngioma: evaluating combined gamma knife and phosphorus-32 brachytherapy

BACKGROUND

Managing residual and recurrent craniopharyngioma effectively is crucial for improving patient outcomes. This study evaluates the combined use of gamma knife and phosphorus-32 brachytherapy, offering insights into alternative, less invasive treatment strategies.

METHODS

We conducted a retrospective analysis of 97 patients treated from 2010 to 2016 for residual and recurrent craniopharyngioma using gamma knife and phosphorus-32 brachytherapy. We classified these patients into three groups: superficial solid (Group A), simple cystic (Group B), and mixed cystic-solid (Group C). We assessed the treatment's effectiveness by the tumor control rates and evaluated safety by monitoring vision, endocrine function improvements, and complication rates.

RESULTS

The treatment achieved complete and adequate control rates of 49.5% and 87.6%, respectively. We observed improvements in vision or visual fields in 55.1% of the patients. The morbidity rate was 15.5%. The study found no significant differences in tumor control rates among the various lesion types.

CONCLUSION

The combination of gamma knife and phosphorus-32 brachytherapy presents a viable, minimally invasive alternative for treating residual and recurrent craniopharyngioma. It offers high tumor control and functional improvement rates, suggesting its potential as a preferred strategy in some instances.

Integrating Systemic Therapies into the Multimodality Therapy of Patients with Craniopharyngioma

OPINION STATEMENT

The integration of targeted therapy into the multimodal management of craniopharyngiomas represents a significant advancement in the field of neuro-oncology. Historically, the management of these tumors has been challenging due to their proximity to vital brain structures, necessitating a delicate balance between tumor control and the preservation of neurological function. Traditional treatment modalities, such as surgical resection and radiation, while effective, carry their own set of risks, including potential damage to surrounding healthy tissues and the potential for long-term side effects. Recent insights into the molecular biology of craniopharyngiomas, particularly the discovery of the BRAF V600E mutation in nearly all papillary craniopharyngiomas, have paved the way for a targeted systemic treatment approach. However, advances have been limited for adamantinomatous craniopharyngiomas. The success of BRAF/MEK inhibitors in clinical trials underscores the potential of these targeted therapies not only to control tumor growth but also to reduce the need for more invasive treatments, potentially minimizing treatment-related complications. However, the introduction of these novel therapies also brings forth new challenges, such as determining the optimal timing, sequencing, and duration of targeted treatments. Furthermore, there are open questions regarding which specific BRAF/MEK inhibitors to use, the potential need for combination therapy, and the strategies for managing intolerable adverse events. Finally, ensuring equitable access to these therapies, especially in healthcare systems with limited resources, is crucial to prevent widening healthcare disparities. In conclusion, targeted therapy with BRAF/MEK inhibitors holds great promise for improving outcomes and quality of life for patients with BRAF-mutated craniopharyngiomas. However, additional research is needed to address the questions that remain about its optimal use and integration into comprehensive treatment plans.

National UK guidelines for the management of paediatric craniopharyngioma

Although rare, craniopharyngiomas constitute up to 80% of tumours in the hypothalamic-pituitary region in childhood. Despite being benign, the close proximity of these tumours to the visual pathways, hypothalamus, and pituitary gland means that both treatment of the tumour and the tumour itself can cause pronounced long-term neuroendocrine morbidity against a background of high overall survival. To date, the optimal management strategy for these tumours remains undefined, with practice varying between centres. In light of these discrepancies, as part of a national endeavour to create evidence-based and consensus-based guidance for the management of rare paediatric endocrine tumours in the UK, we aimed to develop guidelines, which are presented in this Review. These guidelines were developed under the auspices of the UK Children's Cancer and Leukaemia Group and the British Society for Paediatric Endocrinology and Diabetes, with the oversight and endorsement of the Royal College of Paediatrics and Child Health using Appraisal of Guidelines for Research & Evaluation II methodology to standardise care for children and young people with craniopharyngiomas.

Radiotherapy for rare primary brain tumors

Rare central nervous system tumors are defined by an incidence rate of less than 6 cases per 100 000 individuals a year. It comprises a large panel of entities including medulloblastoma, glioneuronal tumors, solitary fibrous tumors, rare pituitary tumors, ependymal or embryonal tumors. The management of these tumors is not clearly defined and radiotherapy indications should be discussed at a multidisciplinary board. Image-guided and intensity-modulated radiation therapy should be proposed and MRI has a fundamental place in the treatment preparation. To avoid the occurrence of side effects, proton therapy is playing an increasingly role for the treatment of these tumors.

Craniopharyngioma in Pediatrics and Adults

Craniopharyngiomas are rare malignancies of dysembryogenic origin, involving the sellar and parasellar areas. These low-grade, epithelial tumors account for two main histological patterns (adamantinomatous craniopharyngioma and papillary craniopharyngioma), which differ in epidemiology, pathogenesis, and histomorphological appearance. Adamantinomatous craniopharyngiomas typically show a bimodal age distribution (5-15 years and 45-60 years), while papillary craniopharyngiomas are limited to adult patients, especially in the fifth and sixth decades of life. Recently, craniopharyngioma histological subtypes have been demonstrated to harbor distinct biomolecular signatures. Somatic mutations in CTNNB1 gene encoding β-catenin have been exclusively detected in adamantinomatous craniopharyngiomas, which predominantly manifest as cystic lesions, while papillary craniopharyngiomas are driven by BRAF V600E mutations in up to 95% of cases and are typically solid masses. Despite the benign histological nature (grade I according to the World Health Organization classification), craniopharyngiomas may heavily affect long-term survival and quality of life, due to their growth pattern in a critical region for the presence of eloquent neurovascular structures and possible neurological sequelae following their treatment. Clinical manifestations are mostly related to the involvement of hypothalamic-pituitary axis, optic pathways, ventricular system, and major blood vessels of the circle of Willis. Symptoms and signs referable to intracranial hypertension, visual disturbance, and endocrine deficiencies should promptly raise the clinical suspicion for sellar and suprasellar pathologies, advocating further neuroimaging investigations, especially brain MRI. The optimal therapeutic management of craniopharyngiomas is still a matter of debate. Over the last decades, the surgical strategy for craniopharyngiomas, especially in younger patients, has shifted from the aggressive attempt of radical resection to a more conservative and individualized approach via a planned subtotal resection followed by adjuvant radiotherapy, aimed at preserving functional outcomes and minimizing surgery-related morbidity. Whenever gross total removal is not safely feasible, adjuvant radiotherapy (RT) and stereotactic radiosurgery (SRS) have gained an increasingly important role to manage tumor residual or recurrence. The role of intracavitary therapies, including antineoplastic drugs or sealed radioactive sources, is predominantly limited to monocystic craniopharyngiomas as secondary therapeutic option. Novel findings in genetic profiling of craniopharyngiomas have unfold new scenarios in the development of targeted therapies based on brand-new biomolecular markers, advancing the hypothesis of introducing neoadjuvant chemotherapy regimens in order to reduce tumor burden prior to resection. Indeed, the rarity of these neoplasms requires a multispecialty approach involving an expert team of endocrinologists, neurosurgeons, neuro-ophthalmologists, neuroradiologists, radiotherapists, and neuro-oncologists, in order to pursue a significant impact on postoperative outcomes and long-term prognosis.

The Role of Surgical Approaches in the Multi-Modal Management of Adult Craniopharyngiomas

Craniopharyngiomas are rare, benign primary brain tumors that arise from remnants of the craniopharyngeal duct epithelium within the sellar and suprasellar region. Despite their benign biology, they may cause significant morbidity, secondary to involvement of nearby eloquent neural structures, such as the pituitary gland, hypothalamus, and optic apparatus. Historically, aggressive surgical resection was the treatment goal to minimize risk of tumor recurrence via open transcranial midline, anterolateral, and lateral approaches, but could lead to clinical sequela of visual, endocrine, and hypothalamic dysfunction. However, recent advances in the endoscopic endonasal approach over the last decade have mostly supplanted transcranial surgery as the optimal surgical approach for these tumors. With viable options for adjuvant radiation therapy, targeted medical treatment, and alternative minimally invasive surgical approaches, the management paradigm for craniopharyngiomas has shifted from aggressive open resection to more minimally invasive but maximally safe resection, emphasizing quality of life issues, particularly in regards to visual, endocrine, and hypothalamic function. This review provides an update on current multi-modal approaches for craniopharyngiomas, highlighting the modern surgical treatment paradigm for this disease entity.

Dosimetric parameters associated with the long-term oncological outcomes of Gamma Knife surgery for sellar and parasellar tumors in pediatric patients

OBJECTIVE

The authors aimed to investigate the dosimetric parameter and the minimally required dose associated with long-term control of sellar and parasellar tumors after Gamma Knife surgery (GKS) in children.

METHODS

A retrospective analysis was performed on pediatric patients younger than 19 years of age who were diagnosed with sellar and parasellar tumors and received GKS at the authors' institution from 1998 to 2019. Cox proportional hazards regression analyses were used to investigate the dosimetric parameters associated with treatment outcome. The Kaplan-Meier method was used to analyze tumor control rates after GKS.

RESULTS

Overall, 37 patients with 40 sellar and parasellar tumors, including 22 craniopharyngiomas and 12 pituitary adenomas, had a mean follow-up of 85.8 months. The gross target volume was 0.05 cm3 to 15.28 cm3, and the mean marginal dose was 15.8 Gy (range 9.6-30.0 Gy). Ten patients experienced treatment failure at a mean of 28.0 ± 26.7 months. The actuarial 5- and 10-year tumor control rates were 79.0% and 69.8%, respectively. D98% was an independent predictive factor of tumor control (HR 0.846 [95% CI 0.749-0.956], p = 0.007), with a cutoff value of 11.5 Gy for the entire cohort and 10 Gy for the craniopharyngioma group. Visual deterioration occurred in 2 patients with the maximum point dose of 10.1 Gy and 10.6 Gy to the optic apparatus.

CONCLUSIONS

In pediatric patients, D98% was a reliable index of the minimum required dose for long-term control of sellar and parasellar tumors after GKS. The optimal D98% value for each tumor diagnosis needs to be elucidated in the future.

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.

Craniopharyngiomas: Surgery and Radiotherapy

Taking into account the benign nature of craniopharyngiomas, the main method of treatment is the resection of the tumor. However, the tendency of these tumors to invade critical structures (such as optic pathways, the hypothalamic-pituitary system, the Willis circle vessels) often limits the possibility of a radical surgery.Craniopharyngiomas of the third ventricle represent the greatest challenge for surgery. After radical surgery, hypothalamic disorders often occur, including not only obesity but also cognitive, emotional, mental, and metabolic disturbances. Metabolic disorders associated with damage to the hypothalamus progress after surgery and lead to impaired functions of the internal organs. This process is irreversible and, in many cases, becomes the direct cause of mortality. The life expectancy of patients with the surgically affected hypothalamus is significantly shorter than in patients with preserved diencephalic function. The incidence of hypothalamic disorders after surgery can reach 40%.Even with macroscopically total resection, craniopharyngiomas can recur in 10-30% of cases, and in the presence of tumor remnants and with no further radiation treatment, the risk of recurrence significantly increases to up to 50-85% according to various studies. For this reason, the observation of patients with residual tumors after surgery is an incorrect strategy.Radiation therapy significantly improves progression-free survival (PFS), and the use of stereotactic irradiation techniques ensures conformity of irradiation of tumor remnants with a complicated shape and location (Iwata H et al., J Neurooncol 106(3):571-577, 2012; Aggarwal et al., Pituitary 16(1):26-33, 2013; Savateev et al., Zh Vopr Neirokhir Im N N Burdenko 81(3):94-106; 2017), which potentially reduces the risk of undesirable postradiation effects. Therefore, the quality of life in patients with craniopharyngiomas infiltrating the hypothalamus is significantly higher after non-radical operations with subsequent stereotactic radiation than after a total or subtotal removal.

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.

Pituitary Surgery

Surgery, more specifically transsphenoidal approach, remains the primary treatment chosen for the majority of pituitary tumors (except for prolactinomas where medical treatment is indicated) allowing for pathologic analysis and complete or partial tumor removal. Transcranial approaches, employing craniotomies, are still needed in some patients with giant pituitary adenomas and in many of those harboring craniopharyngiomas. However, the surgical treatment of pituitary tumors is challenging because of their complex anatomical location and their heterogenous histology. Due to the proximity of critical structures, a successful surgical procedure may often not be achievable due to the high risks related to the procedure itself. Therefore, the treatment of pituitary tumors in 2020 commonly requires a multimodal approach, including surgery, radiosurgery, radiation therapy, and medical therapy. Recently, efforts have been made to develop intraoperative imaging, by increasing the diffusion of radiosurgery. Furthermore, the development of Pituitary Tumor Centers of Excellence (PTCOE) is becoming crucial to provide the optimal treatment for a single patient. There is in fact sufficient evidence that the best and optimal outcome in terms of tumor resection and correction of hormonal over secretion as well as the lowest rate of complications are obtained in centers of excellence with sufficiently experienced, specialized surgeons and a high patient load. Technological developments will probably even gain increasing importance in the future.

Gamma Knife Radiosurgery for Pituitary Tumors: A Systematic Review and Meta-Analysis

Simple Summary

Pituitary tumors represent approximately 10–15% of all brain neoplasms. Gamma Knife, the most commonly used stereotactic radiosurgery technique worldwide, plays an important role in the treatment of several pituitary neoplasm. It is currently used in cases of residual or recurrent tumors after surgery or as primary treatment when surgery is contraindicated. Its goals are long-term tumor control, preservation of visual function, and, for secreting pituitary adenomas, endocrine remission. Several retrospective case-series (level of evidence IV) on Gamma Knife for pituitary tumors have been published describing encouraging outcomes; only one systematic review and meta-analysis on non-functioning pituitary adenoma has been recently reported. We provide a systematic review of the literature and meta-analysis from the last two decades on Gamma Knife radiosurgery for several pituitary tumors with the aim of describing and confirming safety and effectiveness of this technique.

Abstract

To describe and evaluate outcomes of Gamma Knife radiosurgery (GK) for the treatment of pituitary tumors over the past twenty years, a systematic review and meta-analysis according to PRISMA statement was performed. Articles counting more than 30 patients were included. A weighted random effects models was used to calculate pooled outcome estimates. From 459 abstract reviews, 52 retrospective studies were included. Among them, 18 reported on non-functioning pituitary adenomas (NFPA), 13 on growth hormone (GH)-secreting adenomas, six on adrenocorticotropic hormone (ACTH)-secreting adenomas, four on prolactin hormone (PRL)-secreting adenomas, and 11 on craniopharyngiomas. Overall tumor control and five-year progression free survival (PFS) estimate after one GK procedure for NFPA was 93% (95% CI 89–97%) and 95% (95% CI 91–99%), respectively. In case of secreting pituitary adenomas, overall remission (cure without need for medication) estimates were 45% (95% CI 35–54%) for GH-secreting adenomas, 64% (95% CI 0.52–0.75%) for ACTH-secreting adenomas and 34% (95% CI: 19–48%) for PRL-secreting adenomas. The pooled analysis for overall tumor control and five-year PFS estimate after GK for craniopharyngioma was 74% (95% CI 67–81%) and 70% (95% CI: 64–76%), respectively. This meta-analysis confirms and quantifies safety and effectiveness of GK for pituitary tumors.

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.

Optimizing stereotactic radiosurgery in patients with recurrent or residual craniopharyngiomas

PURPOSE

Stereotactic radiosurgery (SRS) is an important management strategy for residual and recurrent craniopharyngiomas. The current study evaluated the factors which affected tumor control and complications in craniopharyngioma SRS.

METHODS

This study includes 53 consecutive patients who underwent single-session SRS for recurrent or residual craniopharyngiomas. The median age was 41 years with 28 male and 25 females. The median tumor volume was 0.63 cm³ and median margin dose was 12 Gy (range 9-25 Gy).

RESULTS

The overall 3-, 5-, and 10-year survival rates were 97.8%, 92.7% and 88.5%. The overall 3-, 5-, and 10-year tumor control rates were 81.0%, 72.1%, and 53.4%. In univariate analysis, ≥ 3 mm distance from optic structures (p = 0.002), only solid or cystic tumor type (p = 0.037), and ≥ 12 Gy to ≥ 85% of the tumor (p < 0.001) were significantly associated with improved tumor control. In multivariate analysis, only solid or cystic tumor type, (p = 0.034), and ≥ 85% of the tumor receiving ≥ 12 Gy (p = 0.004) were significantly associated with better tumor control. When ≥ 85% of the tumor received ≥ 12 Gy the tumor control rates at 3-, 5-, and 10-year were 100%, 93.3%, and 93.3%. Higher conformity index was not associated with better tumor control.

CONCLUSIONS

The tumor control rates after recurrent or residual craniopharyngiomas SRS were improved by ensuring that at least 85% of the tumor received ≥ 12 Gy even when the distance between the tumor and the optic system is < 3 mm. This concept refutes the conformity theory that a high conformity index is a critical feature of effective SRS.

ESTRO ACROP guideline for target volume delineation of skull base tumors

BACKGROUND AND PURPOSE

For skull base tumors, target definition is the key to safe high-dose treatments because surrounding normal tissues are very sensitive to radiation. In the present work we established a joint ESTRO ACROP guideline for the target volume definition of skull base tumors.

MATERIAL AND METHODS

A comprehensive literature search was conducted in PubMed using various combinations of the following medical subjects headings (MeSH) and free-text words: "radiation therapy" or "stereotactic radiosurgery" or "proton therapy" or "particle beam therapy" and "skull base neoplasms" "pituitary neoplasms", "meningioma", "craniopharyngioma", "chordoma", "chondrosarcoma", "acoustic neuroma/vestibular schwannoma", "organs at risk", "gross tumor volume", "clinical tumor volume", "planning tumor volume", "target volume", "target delineation", "dose constraints". The ACROP committee identified sixteen European experts in close interaction with the ESTRO clinical committee who analyzed and discussed the body of evidence concerning target delineation.

RESULTS

All experts agree that magnetic resonance (MR) images with high three-dimensional spatial accuracy and tissue-contrast definition, both T2-weighted and volumetric T1-weighted sequences, are required to improve target delineation. In detail, several key issues were identified and discussed: i) radiation techniques and immobilization, ii) imaging techniques and target delineation, and iii) technical aspects of radiation treatments including planning techniques and dose-fractionation schedules. Specific target delineation issues with regard to different skull base tumors, including pituitary adenomas, meningiomas, craniopharyngiomas, acoustic neuromas, chordomas and chondrosarcomas are presented.

CONCLUSIONS

This ESTRO ACROP guideline achieved detailed recommendations on target volume definition for skull base tumors, as well as comprehensive advice about imaging modalities and radiation techniques.

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.

Postoperative Long-term Outcomes of Patient with Craniopharyngioma Based on CyberKnife Treatment

Objective

The results of CyberKnife treatment in patients with craniopharyngiomas are excellent, but reports of long-term follow-up are rare. Hence, considering the possibility of a long-term follow-up of five years or more, we examined the long-term prognoses of these patients.

Materials and Methods

Of 33 patients, 12 were males and 21 were females. On postoperative evaluation, three patients experienced recurrence after total resection and were treated using CyberKnife. Twenty-five patients were treated with CyberKnife after partial resection. The mean age at treatment was 47 years, and the follow-up period was 61 to 129 months.

Results

Of the cases assessed as totally resected in the postoperative evaluation, three recurred after 18 months. CyberKnife treatment was administered immediately in recurrent cases; subsequently, no recurrences were observed for 25 months or more. No recurrences were observed in any patients treated with CyberKnife on the residual site after surgical treatment. Many cases had improved pituitary function, but none had deteriorated. In addition, no case of visual function deterioration was reported. 

Conclusion

Twenty years have passed since the introduction of CyberKnife treatment; however, only a few reports have examined the long-term prognosis of patients with craniopharyngiomas who underwent this treatment. We have been aware of the efficacy of CyberKnife treatment for ten years or more; its long-term results are evident, and the good growth control and low adverse effects are impressive. We are confident that we can maintain good treatment results by combining conservative surgical resection with minimal complications and CyberKnife treatment for new patients in the future.

Successful application of stereotactic radiosurgery for multiply recurrent Rathke’s cleft cysts

OBJECTIVE

Rathke’s cleft cysts (RCCs) are benign lesions of the sella turcica that usually come to neurosurgical attention due to compression of the optic apparatus (OA) and headaches. Treatment options for these lesions include observation, aspiration of cyst contents, or open resection of the cyst with the cyst wall. All of these options involve the potential for cyst recurrence or enlargement. In this study the authors report on a potential new therapeutic option for RCCs, i.e., stereotactic radiosurgery (SRS).

METHODS

A retrospective review was conducted of 5 patients with histologically confirmed, multiply recurrent RCCs who were treated with single-fraction SRS at a tertiary referral academic medical center.

RESULTS

The total cohort consisted of 5 female patients with an average age of 31.8 years. The most common presenting symptom was headache followed by blurry vision. The symptoms were present on average for 7 months before intervention. The median number of surgeries prior to radiosurgery was 2. The average volume of lesion treated was 0.34 cm3. The median SRS dose was 12.5 Gy prescribed to the 50% isodose line with an average prescription coverage of 96.6%. The median dose to the OA was 5 Gy. At last follow-up, 3 of 5 cysts had completely regressed, 1 had regressed by more than 50% but was still present, and 1 was stable, with an overall mean follow-up duration of 34.2 months. There were no neurological, endocrinological, or visual complications attributable to SRS during the follow-up period.

CONCLUSIONS

RCCs can be a challenging clinical entity to treat, especially when they are multiply recurrent. In patients with an average of 2 previous surgeries for resection, a single SRS session prevented recurrence universally, with an average follow-up of almost 3 years. These results indicate that further investigation of the treatment of RCCs with SRS is indicated.

Gamma Knife Surgery for Residual or Recurrent Craniopharyngioma After Surgical Resection: A Multi-institutional Retrospective Study in Japan

Objective

The optimal treatment for a craniopharyngioma has been controversial. Complete resection is ideal, but it has been difficult to obtain total resection in many cases because of intimate proximity to critical structures such as the optic pathway, hypothalamus, and pituitary gland. A growing number of studies have demonstrated the utility of radiosurgery in controlling residual or recurrent craniopharyngioma. However, most of them are small series. The aim of this multi-institutional study was to clarify the efficacy and safety of Gamma Knife (Elekta, Stockholm, Sweden) surgery for patients with a craniopharyngioma.

Methods

This was a multi-institutional retrospective study by 16 medical centers of the Japan Leksell Gamma Knife Society. Data on patients with craniopharyngiomas treated with Gamma Knife Surgery (GKS) between 1991 and 2013 were obtained from individual institutional review board-approved databases at each center. A total of 242 patients with craniopharyngioma were included in this study. The mean age of the patients was 41 (range, 3 to 86) years. The median follow-up time was 61.4 months (range, 3 to 180 months). The mean radiosurgery target volume was 3.1 ml (range, 0.03-22.3 ml), and the mean marginal dose was 11.4 Gy (range, 8-20.4 Gy).

Results

Two-hundred twenty patients were alive at the time of the last follow-up visit. The three-, five-, and 10-year overall survival rates after GKS were 95.4%, 92.5%, and 82.0%, respectively. The three-, five-, and 10-year progression-free survival rates after GKS were 73.1%, 62.2%, and 42.6% respectively. The rate of radiation-induced complications was 6.2%.

Conclusion

GKS is effective for controlling the tumor growth of craniopharyngiomas with an acceptable complication rate.

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.

Ten-Year Follow-Up of Collision Tumors Composed of Craniopharyngioma and Pituitary Adenoma: A Case Report and Literature Review

Although craniopharyngioma (CP) and pituitary adenoma (PA) are common tumors of the parasellar lesions, the coexistence of CP and PA is very rare. A 48-year-old male visited our hospital because of consciousness disturbance. The neuroimaging revealed a sellar tumor contact with a massive suprasellar cyst including calcification. Preoperative diagnosis was CP, and the patient underwent craniotomy to resolve the suprasellar mass effect. The histological examination disclosed adamantinomatous CP, and subsequently a transsphenoidal approach was chosen for the residual intrasellar tumor. Against expectations, the histological diagnosis was not CP but PA. The patient underwent gamma knife surgery for the residual tumor, and the postoperative course was good. After a 10-year follow-up, both lesions were still completely controlled. If we had suspected and diagnosed the tumor involved as not only CP but also PA at the first operation, the second operation could have been avoided because we would have chosen gamma knife surgery for the residual tumor. We should draw attention to this rare situation for differential diagnosis of parasellar tumor to avoid unnecessary surgery and to decide the best strategy for treatment. In addition, the biological behavior of collision tumors composed of CP and PA is probably the same as solitary CP or PA based on a long-term follow-up of our case.

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.

Radiotherapy Advances in Pediatric Neuro-Oncology

Radiation therapy (RT) represents an integral component in the treatment of many pediatric brain tumors. Multiple advances have emerged within pediatric radiation oncology that aim to optimize the therapeutic ratio—improving disease control while limiting RT-related toxicity. These include innovations in treatment planning with magnetic resonance imaging (MRI) simulation, as well as increasingly sophisticated radiation delivery techniques. Advanced RT techniques, including photon-based RT such as intensity-modulated RT (IMRT) and volumetric-modulated arc therapy (VMAT), as well as particle beam therapy and stereotactic RT, have afforded an array of options to dramatically reduce radiation exposure of uninvolved normal tissues while treating target volumes. Along with advances in image guidance of radiation treatments, novel RT approaches are being implemented in ongoing and future prospective clinical trials. As the era of molecular risk stratification unfolds, personalization of radiation dose, target, and technique holds the promise to meaningfully improve outcomes for pediatric neuro-oncology patients.

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.

Therapeutic outcomes of transsphenoidal surgery in pediatric patients with craniopharyngiomas: a single-center study

OBJECTIVE The aim of this study was to analyze the outcomes of transsphenoidal surgery (TSS) in a single-center clinical series of pediatric craniopharyngioma patients treated with gross-total resection (GTR). METHODS The authors retrospectively reviewed the surgical outcomes for 65 consecutive patients with childhood craniopharyngiomas (28 girls and 37 boys, mean age 9.6 years) treated with TSS (45 primary and 20 repeat surgeries) between 1990 and 2015. Tumors were classified as subdiaphragmatic or supradiaphragmatic. Demographic and clinical characteristics, including extent of resection, complications, incidence of recurrence, pre- and postoperative visual disturbance, pituitary function, and incidence of diabetes insipidus (DI), as well as new-onset obesity, were analyzed and compared between the primary surgery and repeat surgery groups. RESULTS Of the 45 patients in the primary surgery group, 26 (58%) had subdiaphragmatic tumors and 19 had supradiaphragmatic tumors. Of the 20 patients in the repeat surgery group, 9 (45%) had subdiaphragmatic tumors and 11 had supradiaphragmatic tumors. The only statistically significant difference between the 2 surgical groups was in tumor size; tumors were larger (mean maximum diameter 30 mm) in the primary surgery group than in the repeat surgery group (25 mm) (p = 0.008). GTR was accomplished in 59 (91%) of the 65 cases; the GTR rate was higher in the primary surgery group than in the repeat surgery group (98% vs 75%, p = 0.009). Among the patients who underwent GTR, 12% experienced tumor recurrence, with a median follow-up of 7.8 years, and recurrence tended to occur less frequently in primary than in repeat surgery patients (7% vs 27%, p = 0.06). Of the 45 primary surgery patients, 80% had deteriorated pituitary function and 83% developed DI, whereas 100% of the repeat surgery patients developed these conditions. Among patients with preoperative visual disturbance, vision improved in 62% but worsened in 11%. Visual improvement was more frequent in primary than in repeat surgery patients (71% vs 47%, p < 0.001), whereas visual deterioration was less frequent following primary surgery than repeat surgery (4% vs 24%, p = 0.04). Among the 57 patients without preoperative obesity, new-onset postoperative obesity was found in 9% of primary surgery patients and 21% of repeat surgery patients (p = 0.34) despite aggressive resection, suggesting that hypothalamic dysfunction was rarely associated with GTR by TSS in this series. However, obesity was found in 25% of the repeat surgery patients preoperatively due to prior transcranial surgery. Although there were no perioperative deaths, there were complications in 12 cases (18%) (6 cases of CSF leaks, 3 cases of meningitis, 2 cases of transient memory disturbance, and 1 case of hydrocephalus). Postoperative CSF leakage appeared to be more common in repeat than in primary surgery patients (20% vs 4.4%, p = 0.2). CONCLUSIONS The results of TSS for pediatric craniopharyngioma in this case series suggest that GTR should be the goal for the first surgical attempt. GTR should be achievable without serious complications, although most patients require postoperative hormonal replacement. When GTR is not possible or tumor recurrence occurs after GTR, radiosurgery is recommended to prevent tumor regrowth or progression.

Pediatric Craniopharyngiomas: A Primer for the Skull Base Surgeon

Pediatric craniopharyngioma is a rare sellar-region epithelial tumor that, in spite of its typically benign pathology, has the potential to be clinically devastating, and presents a host of formidable management challenges for the skull base surgeon. Strategies in craniopharyngioma care have been the cause of considerable controversy, with respect to both philosophical and technical issues. Key questions remain unresolved, and include optimizing extent-of-resection goals; the ideal radiation modality and its role as an alternative, adjuvant, or salvage treatment; appropriate indications for expanded endoscopic endonasal surgery as an alternative to transcranial microsurgery; risks and benefits of skull base techniques in a pediatric population; benefits of and indications for intracavitary therapies; and the preferred management of common treatment complications. Correspondingly, we sought to review the preceding basic science and clinical outcomes literature on pediatric craniopharyngioma, so as to synthesize overarching recommendations, highlight major points of evidence and their conflicts, and assemble a general algorithm for skull base surgeons to use in tailoring treatment plans to the individual patient, tumor, and clinical course. In general terms, we concluded that safe, maximal, hypothalamic-sparing resection provides very good tumor control while minimizing severe deficits. Endoscopic endonasal, intraventricular, and transcranial skull base technique all have clear roles in the armamentarium, alongside standard craniotomies; these roles frequently overlap, and may be further optimized by using the approaches in adaptive combinations. Where aggressive subtotal resection is achieved, patients should be closely followed, with radiation initiated at the time of progression or recurrence-ideally via proton beam therapy, although three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and stereotactic radiosurgery are very appropriate in a range of circumstances, governed by access, patient age, disease architecture, and character of the recurrence. Perhaps most importantly, outcomes appear to be optimized by consolidated, multidisciplinary care. As such, we recommend treatment in highly experienced centers wherever possible, and emphasize the importance of longitudinal follow-up-particularly given the high incidence of recurrences and complications in a benign disease that effects a young patient population at risk of severe morbidity from hypothalamic or pituitary injury in childhood.

Clinical outcomes following proton therapy for children with central nervous system tumors referred overseas

BACKGROUND

International, multidisciplinary care of children with central nervous system (CNS) tumors presents unique challenges. The aim of this study is to report patient outcomes of U.K. children referred for proton therapy to a North American facility.

METHODS

From 2008 to 2016, 166 U.K. children with approved CNS tumors were treated with proton therapy at a single academic medical center in the United States. Median age was 7 years (range, 1-19). Median follow-up was 2.6 years.

RESULTS

The 3-year actuarial overall survival (OS) and local control (LC) rates were 96% and 91%, respectively, for the overall group, 92% and 85% for the ependymoma subgroup (n = 57), 95% and 88% for the low-grade glioma subgroup (n = 54), and 100% and 100%, respectively, for the craniopharyngioma subgroup (n = 45). Cyst expansion was observed in 13 patients, including one case resulting in visual impairment. Serious side effects included new-onset seizures in three patients (1.8%), symptomatic vasculopathy in three patients (1.8%), and symptomatic brainstem necrosis in one patient (0.6%).

CONCLUSIONS

In this cohort of British children referred overseas for proton therapy, disease control does not appear compromised, toxicity is acceptable, and improvement in long-term function is anticipated in survivors owing to the reduced brain exposure afforded by proton therapy.

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.

[Radiotherapy and radiosurgery in treatment of craniopharyngiomas]

Craniopharyngiomas are benign epithelial tumors having a dysembryogenetic origin, which are usually located in the sellar/parasellar and/or third ventricle regions. Gross total resection is the modern standard of treatment for these tumors because of a low recurrence rate. However, this surgery in some patients with craniopharyngioma often leads to the development or worsening of diencephalic disorders poorly responding to treatment. Perhaps, in these cases, subtotal or partial tumor resection or implantation of an Ommaya reservoir into the tumor cyst followed by stereotactic radiotherapy/radiosurgery may provide better functional outcomes and higher life quality in patients, with tumor growth control being reasonable (according to the published data, the mean 10-year disease-free survival is 66.9% after total tumor resection and 79.6% after combined treatment). The paper presents a review of the literature on radiological treatment of craniopharyngiomas. We discuss the issues of indications, optimal timing of radiotherapy/radiosurgery, its efficacy, and treatment outcomes in terms of complications and quality of life. Particular attention is paid to enlargement of craniopharyngioma cysts during and after radiological treatment.

Radiosurgery for Pediatric Brain Tumors

The utility of radiosurgery for pediatric brain tumors is not well known. For children, radiosurgery may have an important role for treating unresectable tumors, residual disease, or tumors in the recurrent setting that have received prior radiotherapy. The available evidence demonstrates utility for some children with primary brain tumors resulting in good local control. Radiosurgery can be considered for limited residual disease or focal recurrences. However, the potential toxicities are unique and not insignificant. Therefore, prospective studies need to be performed to develop guidelines for indications and treatment for children and reduce toxicity in this population.

Influence of previous treatments on repeat surgery for recurrent craniopharyngiomas in children

PURPOSE

Craniopharyngioma is a common pediatric brain tumor, with a high rate of recurrence after primary treatment. This retrospective study investigated the effect of various primary treatments on surgical strategies and outcomes for recurrent craniopharyngiomas.

METHODS

The study population comprised 35 children (mean age 8.77 years, range 1-16 years) with recurrent craniopharyngioma re-operated from January 1990 to January 2009. The recurrent craniopharyngiomas were excised whenever possible. For analysis, the patients were divided into four groups according to the primary treatment: radical tumor resection (A), incomplete tumor resection (B), radiotherapy + incomplete tumor resection (C), and Ommaya reservoir placement + incomplete tumor resection (D).

RESULTS

Group B had a significantly shorter recurrence-free interval than groups A, C, or D. Outcomes were significantly different among the four groups. The hypothalamic status scores of groups A (2.38 ± 0.27) and C (2.28 ± 0.42) were significantly higher than that of group B (1.64 ± 0.20). There were no statistical differences between any two other groups.

CONCLUSIONS

In children, the primary treatments for craniopharyngioma should be considered when choosing the surgical strategy for recurrence. Radiotherapy before repeated surgery can result in a worse functional outcome and hypothalamic-pituitary function.

Endoscopic transnasal external fistulation in recurrent cystic subdiaphragmatic craniopharyngioma: a novel technique

The authors present a technique for the persistent external drainage of intractable subdiaphragmatic cystic recurrences with the creation of a fistula between the cyst wall epithelium and epithelium on the nasal cavity, using a pedicled nasoseptal flap as a conduit. The long-term efficacy of endoscopic transnasal external fistulation (ETEF) in controlling cystic recurrences in this patient group is addressed through a retrospective observational review of 3 male patients aged 8, 22, and 45 years with the diagnosis of recurrent cystic subdiaphragmatic craniopharyngioma who underwent the ETEF procedure between 2006 and 2009. Clinical presentation, neuroimaging, surgical interventions, and follow-up were recorded. The main outcome measure was cyst reaccumulation on MRI. Patients had a mean follow-up of 76 months (range 5-8 years) with no incidence of cystic recurrence. Follow-up imaging revealed sustained cyst involution contrary to the usual recurrent enlargement commonly seen in this patient group. Symptoms of headache and visual field defects improved post-ETEF. Long-term theoretical complications of a persistent fistula such as intracranial abscess, meningitis, or CSF leak were not observed. ETEF promotes nasalization of cystic recurrences in subdiaphragmatic craniopharyngioma. It is safe and effective, causing long-term involution of cysts and can be considered a definitive procedure.

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.

Recurrent craniopharyngioma after conformal radiation in children and the burden of treatment

OBJECT

In this paper the authors present their experience treating children with recurrent craniopharyngioma who were initially managed with surgery followed by conformal radiation therapy (CRT).

METHODS

A departmental oncology information system was queried to identify all children (< 18 years old) who received CRT for a craniopharyngioma between 1998 and 2010 (inclusive) and specifically those who experienced tumor progression. For each patient, the authors recorded the type of recurrence (solid, cystic, or both), the time interval to first progression and each subsequent progression, the associated treatment complications, and disease status at last follow-up evaluation.

RESULTS

Among the 97 patients that met criteria for entry into this study, 18 (18.6%) experienced tumor progression (9 cystic, 3 solid, 6 cystic and solid). The median time to first recurrence was 4.62 years (range 1.81-9.11 years). The subgroup included 6 female and 12 male patients with a median age of 7.54 years (range 3.61-13.83 years). Ten patients experienced first progression within 5 years of CRT. The 5- and 10-year treatment-free survival rates for the entire cohort were 89.0% (95% confidence interval [CI] 80.5%-93.9%) and 76.2% (95% CI 64%-85%), respectively. Seven patients had a single episode of progression and 11 had more than 1. The time interval between each subsequent progression was progressively shorter. The 18 patients underwent 38 procedures. The median follow-up duration for this group was 9.32 years (range 4.04-19.0 years). Three patients died, including 1 from perioperative complications.

CONCLUSIONS

Craniopharyngioma progression after prior irradiation is exceedingly difficult to treat and local control is challenging despite repeated surgical procedures. Given our results, gross-total resection may need to be the surgical goal at the time of first recurrence, if possible. Decompressing new cyst formation alone has a low rate of long-term success.

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.

Stereotactic radiation therapy for skull base recurrences: Is a salvage approach still possible?

AIM

A literature review was performed to analyse the role of stereotactic radiotherapy given in a single shot or in a fractionated fashion for recurrent skull base tumours in order to ascertain if it can be a real salvage approach.

BACKGROUND

The management of recurrent skull base tumours can have a curative or palliative intent and mainly includes surgery and RT.

MATERIALS AND METHODS

One-thousand-ninety-one articles were found in the search databases and the most relevant of them were analysed and briefly described.

RESULTS

Data on recurrences of meningioma, pituitary adenoma, craniopharyngioma, chordoma and chondrosarcoma, vestibular schwannoma, glomus jugulare tumours, olfactory neuroblastoma and recurrences from head and neck tumours invading the base of skull are reported highlighting the most relevant results in terms of local control, survival, side effects and complications.

CONCLUSIONS

In conclusion, it emerges that SRS and FSRT are effective and safe radiation modalities of realize real salvage treatment for recurrent skull base tumours.

The biology of radiosurgery and its clinical applications for brain tumors

Stereotactic radiosurgery (SRS) was developed decades ago but only began to impact brain tumor care when it was coupled with high-resolution brain imaging techniques such as computed tomography and magnetic resonance imaging. The technique has played a key role in the management of virtually all forms of brain tumor. We reviewed the radiobiological principles of SRS on tissue and how they pertain to different brain tumor disorders. We reviewed the clinical outcomes on the most common indications. This review found that outcomes are well documented for safety and efficacy and show increasing long-term outcomes for benign tumors. Brain metastases SRS is common, and its clinical utility remains in evolution. The role of SRS in brain tumor care is established. Together with surgical resection, conventional radiotherapy, and medical therapies, patients have an expanding list of options for their care. Clinicians should be familiar with radiosurgical principles and expected outcomes that may pertain to different brain tumor scenarios.

Radiation therapy in neurologic disease

Radiotherapy is a primary mode of treatment of many of the disease entities seen by the neurologist. Therefore knowledge of how ionizing radiation works and when it is indicated is a crucial part of the field of Neurology. The neurologist may also be confronted with some of the side effects and complications or radiotherapy treatment. This chapter attempts to serve as a review of the current day process of radiotherapy, a brief review of biology and physics of radiation, and how it is used in the treatment diseases which are common to the Neurologist. In addition we review the more commonly seen side effects and complications of treatment which may be seen by the neurologist.

Management of craniopharyngiomas

Craniopharyngiomas are rare epithelial tumours arising along the path of the craniopharyngeal duct. Their pathogenesis remains uncertain and they can present with a variety of manifestations attributed to pressure effects to surrounding structures. The optimal management of craniopharyngiomas remains challenging mainly due to their sharp, irregular borders and their tendency to adhere to vital neurovascular structures making surgical manipulations potentially hazardous to vital brain areas. Non-aggressive surgery followed by radiotherapy is currently the most widely used option possibly achieving the most optimal long-term outcome. Other treatment modalities including intracystic irradiation, intracystic instillation of antineoplasmatic agents and stereotactic radiotherapy are also available in our armamentarium. The long-term morbidities related with the craniopharyngiomas and their treatment remain significant, with hypothalamic damage playing the protagonist role and requiring further studies to identify measures that will improve the prognosis of the patients.

Should adjuvant radiotherapy be recommended for pediatric craniopharyngiomas?

Intracranial tumors secondary to radiotherapy are rare. In this group gliomas are the rarest. Only 6 cases of glioblastoma multiforme (GBM) have been reported in patients undergoing radiotherapy (RT) for craniopharyngiomas of which only 4 have been in children less than 18 years of age. In recent years RT has become a mainstay of adjuvant therapy for recurrent or partially excised craniopharyngiomas. We report a child of 12 years who had previously undergone RT for a suprasellar craniopharyngioma and presented 10 years later with a GBM. This is the 5th pediatric case in literature demonstrating a GBM after RT for a craniopharyngioma. The implications of subjecting the pediatric population to RT for a benign lesion versus the outcome of gross total removal and management of RT induced tumors is discussed and the need to avail of safer alternatives such as stereotactic radiosurgery is stressed.

Minimally invasive management of adult craniopharyngiomas: An analysis of our series and review of literature

Background:

Craniopharyngiomas (CPs) are slow growing tumors with an incidence of between 1.2% and 4.6%, having a bimodal age distribution typically peaking in childhood and in adults between 45 and 60 years. Recurrences occur even after documented gross total resections necessitating a combination of therapeutic strategies. Obtaining a cure of this tumor in adults without producing major side effects continues to remain elusive.

Methods:

We describe our results in 11 patients with CP treated in a minimally invasive fashion using a combination of techniques like burr hole aspiration, Ommaya reservoir placement, ventriculo-peritoneal (VP) shunting and focal radiation (Gamma Knife stereotactic radiosurgery/Intensity modulated radiotherapy [GKRS/IMRT]).

Results:

Visual function remained intact in all patients; endocrine status remained stable with two patients developing new postoperative diabetes insipidus. There was no periprocedural morbidity or mortality, with hospital stays for any in-patient procedure being 48 hours or less.

Conclusions:

Minimally invasive techniques such as cyst aspiration, insertion of a catheter with Ommaya reservoir, when combined with stereotactic radiosurgery/IMRT is an effective and safe option for management and long-term control of adult CPs. We believe the Ommaya catheter by itself could act as a stent, creating a tract allowing gradual drainage of cyst fluid and stabilization without necessitating any further interventions in selected cases.

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.

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.

Pegylated interferon-α-2b for children with recurrent craniopharyngioma

OBJECT

Previous studies of systemic and intralesional administration of nonpegylated interferon have shown efficacy against craniopharyngioma. Pegylaion of interferon-α-2b (PI) prolongs the half-life, allowing sustained exposure of the drug over time, and enhances efficacy. The authors report the results of the use of PI in 5 children with recurrent craniopharyngiomas.

METHODS

Five children, ranging in age from 9 to 15 years, with recurrent craniopharyngiomas were treated for up to 2 years with subcutaneous injections of PI at a dose of 1-3 μg/kg/week. Tumor response was assessed using MRI.

RESULTS

All patients had stable disease or better in response to PI. One patient experienced a recurrence after gross-total resection (GTR). She initially showed an increase in the predominantly cystic tumor after 3 months of treatment, followed by a complete response. She required no further intervention and remains without evidence of disease 10 years after starting treatment. Another patient experienced recurrence 3.3 years after subtotal resection (STR) and radiation therapy. He had complete disappearance of the predominantly cystic component after 4 months of treatment, and a small residual calcified mass remains 5 years later. The third patient experienced recurrence after 3 GTRs. He had a complete response after 7 months of treatment and remains without evidence of disease 19 months after starting treatment. The fourth patient experienced recurrence after 2 STRs. He had a 30% decrease in tumor size after 4 months of treatment, which was maintained for 12 months at which point the cyst began to increase in size. The final patient experienced recurrence after GTR and has stable disease 6 months after starting treatment with PI.

CONCLUSIONS

The use of PI in children with recurrent craniopharyngiomas can result in significant and durable responses and potentially delay or avoid the need for radiation therapy.