Neuroendoscopic Treatment of Cystic Craniopharyngiomas: A Case Series with Systematic Review of the Literature

Advances in the treatment of Adamantinomatous craniopharyngioma: How to balance tumor control and quality of life in the current environment: a narrative review

Adamantinomatous craniopharyngioma (ACP) presents a significant challenge to neurosurgeons despite its benign histology due to its aggressive behavior and unique growth patterns. This narrative review explores the evolving landscape of ACP treatments and their efficacy, highlighting the continuous development in therapeutic approaches in recent years. Traditionally, complete resection was the primary treatment for ACP, but surgical -related morbidity have led to a shift. The invasive nature of the finger-like protrusions in the histological structure results in a higher recurrence rate for ACP compared to papillary craniopharyngioma (PCP), even after complete macroscopic resection. Given this, combining subtotal resection with adjuvant radiotherapy has shown potential for achieving similar tumor control rates and potentially positive endocrine effects. Simultaneously, adjuvant treatments (such as radiotherapy, intracystic treatment, and catheter implantation) following limited surgery offer alternative approaches for sustained disease control while minimizing morbidity and alleviating clinical symptoms. Additionally, advances in understanding the molecular pathways of ACP have paved the way for targeted drugs, showing promise for therapy. There is a diversity of treatment models for ACP, and determining the optimal approach remains a subject of ongoing debate in the present context. In order to achieve a good-term quality of life (QOL), the main goal of the cyst disappearance or reduction of surgical treatment is still the main. Additionally, there should be a greater emphasis on personalized treatment at this particular stage and the consideration of ACP as a potentially chronic neurosurgical condition. This review navigates the evolving landscape of ACP therapies, fostering ongoing discussions in this complex field.

Transventricular Endoscopic Approach for Cystic Craniopharyngioma: Case Series

Background and Study Aims  The treatment of craniopharyngioma is varied. The treatment ranges from radical excision to direct radiotherapy. As the morbidity of excision is high, more conservative approaches are used. Transventricular endoscopy is a minimally invasive treatment for cystic craniopharyngiomas. The objective of this study is to describe a personal experience with this method of treatment. Material and Methods  This is a retrospective review of a series of patients managed with endoscopic catheter and reservoir placement for cystic craniopharyngiomas. Results  Twenty-nine patients presented with clinical features of raised intracranial features. Imaging showed a predominantly cystic craniopharyngioma extending into the third ventricle with hydrocephalus. All patients underwent transcortical transventricular endoscopic biopsy, and catheter placement connected to a reservoir. There was no morbidity ascribed to the endoscopic procedure when fenestration and aspiration or fenestration and reservoir were placed. Twelve patients underwent radiotherapy. The median duration of follow-up was 18 months (3-72 months). Eight (27.5%) cases had recurrences. Five (17.2%) could be managed with only reaspiration, two (6.8%) required craniotomy and resection, and one (3.4%) could be managed only with ventriculoperitoneal shunt. Conclusion  The neuroendoscopic fenestration, aspiration of cyst, and placement of catheter reservoir followed by radiation is an optional treatment for predominantly cystic craniopharyngiomas arising within or extending into the third ventricle causing hydrocephalus.

Comparing Surgical Approaches for Craniopharyngioma Resection Among Adults and Children: A Meta-analysis and Systematic Review

BACKGROUND

Craniopharyngioma treatment often necessitates surgical resection. Conventional approaches, such as transcranial and transsphenoidal approaches, are predominantly used. However, a recently adopted supraorbital approach may be more efficacious. Thus, this meta-analysis and systematic review aimed to compare the efficacy of the transcranial, transsphenoidal, and supraorbital approaches for resection and treatment of craniopharyngiomas.

METHODS

This study was performed following PRISMA guidelines. Analyses were performed according to study design: (1) analyses for studies comparing several surgical approaches; and (2) analyses of all included studies. Random effects meta-analysis models were used to pool odds ratios among studies comparing several approaches. Similarly, categorical meta-regression models were used to examine the effect of surgical approach as a covariate of outcome data for all studies. Statistics were performed using Comprehensive Meta-Analysis software (CMA 3.3, Biostat, Englewood, NJ) (significance set at P < 0.05).

RESULTS

Patients were well-matched for age, sex, and preoperative comorbidities between groups stratified by surgical approach. Analyses including 22 studies that compared several approaches demonstrated that the transsphenoidal group had a greater occurrence of postoperative visual improvement (P < 0.0001), lesser occurrence of visual deterioration (P < 0.0001), and lower tumor recurrence rate (P = 0.015) compared with the transcranial group. Only 2 studies compared the supraorbital approach to another approach, limiting analyses. Analyses including all studies demonstrated that the supraorbital group did not differ to either the transcranial or transsphenoidal group for any examined variables.

CONCLUSIONS

The present study suggests that the transsphenoidal approach is associated with improved clinical outcomes for craniopharyngioma resection. There are limited data regarding the supraorbital approach, warranting future investigation.

Neuroendoscopic surgery combined with Ommaya reservoir placement for cystic craniopharyngiomas: 11 years of experience in a single institution

INTRODUCTION

Total resection of cystic craniopharyngiomas is challenging, especially for some large cystic tumors, because it is often associated with high recurrence and morbidity rates. Minimally invasive cyst decompression and continuous drainage are appropriate to manage clinical symptoms. We reviewed our experience of the past 11 years to determine the long-term effects of neuroendoscopic surgery (NES) combined with Ommaya reservoir (OR) for the treatment of cystic craniopharyngiomas.

METHODS

We retrospectively analyzed the data of 15 adult patients with cystic craniopharyngiomas at a single institution with the primary goal to evaluate the treatment mode with initial adequate decompression of the cyst under visualization and continuous drainage. The study endpoints were functional outcome, cyst volume changes, and tumor progression.

RESULTS

The median follow up was 77 (20-136) months. Clinical symptoms, e.g. increased intracranial pressure and visual impairment, could be rapidly improved after NES. The postoperative reduction in cyst volume (p < 0.001) and improvement in Karnofsky performance status (p < 0.001) were significant, and long-term tumor control was achieved in 10 patients (67%). Aspiration from the OR after progression of the tumor's cystic portion remains a major option, with only few patients requiring repeat NES procedures. No patient developed acute or severe clinical symptoms during follow up.

CONCLUSIONS

NES could decompress the craniopharyngioma cyst under visualization and enable faster clinical-symptom improvement. The minimally invasive NES combined with OR allowed long-term symptom control in most patients without surgery-related injury. This palliative treatment strategy could be an alternative modality for cystic craniopharyngioma treatment.

Upfront adjuvant irradiation versus postoperative surveillance following incomplete surgical resection of craniopharyngiomas in children and young adults

OBJECTIVE

Incomplete surgical removal of craniopharyngiomas frequently results in suboptimal oncological control. Radiation therapy is usually offered in these cases to prevent local recurrence of disease; however, the efficacy of radiation is limited by its potential adverse effect, particularly in younger patients. This study was undertaken to compare long-term outcomes and rates of postoperative obesity and endocrinopathy in patients undergoing either upfront adjuvant radiation after surgery, or postoperative surveillance with progression-contingent intervention.

METHODS

Thirty-seven patients aged <25 years who had undergone primary incomplete surgical resection of craniopharyngiomas were retrospectively identified and categorized according to the prescribed treatment strategy. Recurrence rates, functional status, neuro-ophthalmologic, and endocrine outcomes were studied in both groups of patients.

RESULTS

Twenty-three patients received upfront adjuvant radiation, and 14 patients underwent postoperative surveillance. Adjuvant radiation in the former group was delivered using either conventional (n=10), 3D-conformal (n=4), or fractionated stereotactic (n=9) techniques using a linear accelerator. The mean follow-up duration was 64.7 months (range 14-134 months). Disease progression was significantly higher in patients undergoing surveillance as compared to those undergoing upfront adjuvant radiation (71.4 versus 17.4%; p=0.002). Median progression-free survival times were 129 months and 27 months in the upfront adjuvant radiation and surveillance groups, respectively (p=0.007). In patients undergoing surveillance, 50% ultimately required irradiation, and the median radiation-free survival time in this subgroup was 57 months. Two children in the adjuvant radiation group developed asymptomatic radiation-related vasculopathies on follow-up; however, there were no statistically significant differences between the two groups in terms of visual, functional, or pituitary-hypothalamic function at last follow-up.

CONCLUSIONS

In comparison to upfront adjuvant radiation following incomplete craniopharyngioma resection significantly, a strategy of postoperative surveillance resulted in less durable disease control but allowed radiation therapy to be delayed by a median time of 57 months, without significant detriment to global functional, visual, and neuro-endocrinological outcomes. The merits and demerits of either strategy should be carefully considered in the post-surgical management of these patients.

Current Advances in the Management of Adult Craniopharyngiomas

Craniopharyngiomas (CPs) are slow growing, histologically benign intracranial tumors located in the sellar–suprasellar region. Although known to have low mortality, their location and relationship to the adjacent neural structures results in patients having significant neurologic, endocrine, and visual comorbidities. The invasive nature of this tumor makes complete resection a challenge and contributes to its recurrence. Additionally, these tumors are bimodally distributed, being treated with surgery, and are followed by other adjuncts, such as focused radiation therapy, e.g., Gamma knife. Advances in surgical techniques, imaging tools, and instrumentations have resulted in the evolution of surgery using endoscopic techniques, with residual components being treated by radiotherapy to target the residual tumor. Advances in molecular biology have elucidated the main pathways involved in tumor development and recurrence, but presently, no other treatments are offered to patients, besides surgery, radiation, and endocrine management, as the disease and tumor evolve. We review the contemporary management of these tumors, from the evolution of surgical treatments, utilizing standard open microscopic approaches to the more recent endoscopic surgery, and discuss the current recommendations for care of these patients. We discuss the developments in radiation therapy, such as radiosurgery, being used as treatment strategies for craniopharyngioma, highlighting their beneficial effects on tumor resections while decreasing the rates of adverse outcomes. We also outline the recent chemotherapy modalities, which help control tumor growth, and the immune landscape on craniopharyngiomas that allow the development of novel immunotherapies.

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.

Endoscopic Transcortical-Transventricular Approach in Treating Third Ventricular Craniopharyngiomas-Case Series With Technical Note and Literature Review

BACKGROUND

A paradigm shift toward less radicality in the treatment of craniopharyngioma (CP) has increasingly gained recognition. In selected patients, a less invasive approach aiming at cyst decompression may be suitable.

OBJECTIVE

To present our experience with the endoscopic transcortical-transventricular approach (ETTA) for the treatment of CP located in the third ventricle, describe our surgical technique, and explore the results reported in the literature.

METHODS

Data for third ventricular CPs treated using ETTA in 2 tertiary medical centers between 2006 and 2020 were retrospectively reviewed. Cystic, mixed lesion, new, and recurrent cases were included. ETTA aimed at cyst fenestration, subtotal or partial tumor resection, managing the hydrocephalus, or a combination of these modalities. Fractionated radiotherapy (RT) was performed (54 Gy in 30 fractions).

RESULTS

The described approach was performed in 13 patients with a mean age of 30.2 years. Tumor excision was attempted in 10 patients. Cystic fenestration alone was conducted in 3 patients, followed by intracystic catheter implantation in 2 patients. Permanent diabetes insipidus developed in 3 patients, and 1 patient experienced a surgical site infection. The recurrence rate for ETTA + RT (pre-ETTA in 33.3%) was 2/9 (22.2%) after a mean follow-up of 21.3 months. Four patients did not undergo RT after ETTA, and all these patients experienced recurrences after a mean follow-up of 15.5 months. Hydrocephalus resolved in all 6 patients who presented with accompanying hydrocephalus.

CONCLUSION

ETTA combined with adjuvant RT is a safe and effective option in the management of cystic or predominantly cystic CP extending into the third ventricle. This procedure also effectively treats the accompanying hydrocephalus.

Treatment of Cystic Craniopharyngiomas: An Update

In spite of the significant technical and technological progress in neurosurgery and the continuous discoveries by the basic research, adamantinomatous craniopharyngioma remains a significant clinical challenge. Actually, the huge size of the tumor, its multiple cystic components, the encasement of Willis' circle and optic pathways, and the invasion of the hypothalamus often prevent its safe surgical resection. Moreover, the local aggressiveness of the tumor accounts for a high risk of recurrence even after a gross total resection. For these reasons, more and more efforts are being dedicated to enhance the knowledge about AC and improve the tools for its treatment.This paper is dedicated to the most recent advances concerning the AC management. Promising, new insights come for the basic research, thanks to the updates on the role of the WNT-β-catenin pathway (important for the tumor genesis and progression, not yet developed enough for a safe target therapy in children but useful for determining the prognosis) and the inflammatory mediators (widely overexpressed, especially by the cyst of the tumor, and for which target therapies are being developed). Moreover, further factors and pathways are under investigation.Also the development of new treatment strategies accounts for the improvement of the prognosis and the quality of life of AC patients. The enhancement of the experience with the endoscopic techniques (both transsphenoidal and transventricular approaches) actually allows to perform a less invasive but effective surgery that can be coupled with new modalities of radiation therapy aiming at obtaining a reliable control of the disease and protecting the endocrinological, ophthalmological, and neurological functions. A special mention is finally deserved by the techniques specifically designed for the intracystic therapy (as cyst fenestration alone or in combination with administration of radionuclides or bleomycin or interferon-α) that are here analyzed together with the aforementioned advances.

Neoadjuvant B-RAF and MEK Inhibitor Targeted Therapy for Adult Papillary Craniopharyngiomas: A New Treatment Paradigm

BACKGROUND

Surgical and clinical management of craniopharyngiomas is associated with high long-term morbidity especially in the case of hypothalamic involvement. Improvements in knowledge of craniopharyngioma molecular biology may offer the possibility of safe and effective medical neoadjuvant treatments in a subset of patients harboring papillary subtype tumors with a BRAFV600E mutation.

METHOD

We report herein two cases of tubero-infundibular and ventricular Papillary Craniopharyngiomas in which BRAF/MEK inhibitor combined therapy was used as adjuvant (Case 1) or neoadjuvant (Case 2) treatment, with a 90% reduction in tumor volume observed after only 5 months. In Case 2 the only surgical procedure used was a minimal invasive biopsy by the trans-ventricular neuroendoscopic approach. As a consequence, targeted therapy was administered in purely neoadjuvant fashion. After shrinkage of the tumor, both patients underwent fractionated radiotherapy on the small tumor remnant to achieve long-term tumor control. A review of a previously reported case has also been performed.

RESULT

This approach led to tumor control with minimal long-term morbidity in both cases. No side effects or complications were reported after medical treatment and adjuvant radiotherapy.

CONCLUSION

Our experience and a review of the literature argue for a change in the current treatment paradigm for Craniopharyngiomas (CPs). In giant and invasive tumors, confirmation of BRAFV600E mutated PCPs by biopsy and BRAF/MEK inhibitor therapy before proposing other treatments may be useful to improve long term outcomes for patients.

Intraventricular Craniopharyngiomas-Overcoming Their Relative Inaccessibility: Institutional Experience With a Review of Literature

Introduction: Craniopharyngiomas constitute 2-4% of intracranial neoplasms. Intraventricular craniopharyngiomas (IVCrs) are the rarely encountered varieties of these lesions. Objective: The objective of the study was to study the special features in clinical presentation, imaging, management, and surgical outcome of IVCrs. Materials and Methods: This retrospective analysis included the combined experience from two tertiary care institutions. Medical records of histopathologically proven cases of IVCrs from January 1994 to June 2021 were assessed, and images were analyzed based on the criteria by Migliore et al. for inclusion of solely intraventricular lesion with the third ventricular ependyma demarcating it from the suprasellar cistern. Results: Among the 25 patients included (mean age: 35.4 years), the most common presentation included headache (n = 21, 84%), vomiting and other features of raised ICP (n = 18, 72%), visual complaints (n = 12, 48%), and endocrinopathies (n = 11, 44%). Fifteen had predominantly cystic tumors, two were purely solid, and eight were of mixed consistency. Primary open microsurgical procedures were performed in 18 (72%) patients, of which four (16%) were endoscope-assisted. Seven (28%) underwent a purely endoscopic procedure. One underwent a staged surgery with endoscopic cyst fenestration and intracystic interferon (IFN)-alpha therapy, followed by microsurgical excision. Complete excision was achieved in 10 patients, near-total in nine, and partial excision in six. Four patients underwent a ventriculoperitoneal shunt (one before the definitive procedure). At a median follow-up of 36 months (range:11-147 months), five patients developed a recurrence, and one had a stable small residue. This patient and two others with small cystic recurrences were observed. One patient was managed with radiotherapy alone. Another underwent re-surgery after a trial of radiotherapy, and the last patient developed a local recurrence, which was managed with radiotherapy; he then later developed an intraparenchymal recurrence, which was operated. Conclusion: Purely IVCrs present with raised intracranial pressure, and visual disturbances are less common. Their deep-seated location and limited surgical field-of-view makes minimally invasive endoscopic-assisted surgery most suitable for their excision. The thin-walled cystic lesions may be occasionally adherent to the ependymal wall in close vicinity to the thalamus-hypothalamus complex, making complete excision difficult. Their responsiveness to radiotherapy, often leads to a gratifying long-term outcome.

La neuroendoscopia: una técnica revolucionaria en el campo de la neurocirugía

La neuroendoscopia es un procedimiento mínimamente invasivo que se desarrolló a principios del siglo pasado y tiene importancia en el campo de la neurocirugía, representa un método innovador ya que aporta una amplia visualización de las estructuras anatómicas con mínimo traumatismo del tejido nervioso, contribuyendo al diagnóstico y tratamiento de diversas afecciones intra y extracraneales. Se realizó una búsqueda bibliográfica con el propósito de identificar, analizar y describir algunas patologías neuroquirúrgicas que se han tratado bajo neuroendoscopia, así como los aportes más relevantes en cirugía pediátrica y de columna, con el fin de exponer el impacto que ha tenido esta técnica en el desarrollo de la cirugía moderna.

Neuroendoscopic Transventricular Approach for Cystic Craniopharyngioma

The literature is rich with many studies reporting different treatment modalities and approaches for cystic craniopharyngioma (CC), including microsurgery, neuroendoscopic transventricular approach, endoscopic transnasal surgery, stereotactic drainage, and Ommaya reservoir insertion. The goals of this manuscript are to report the successful treatment of an atypical case of CC using the neuroendoscopic transventricular approach (NTVA) as well as discuss the different surgical modalities for these tumors following a comprehensive review of the literature. Our patient is a nine-year-old female with a large CC who was managed using the NTVA. No complications or recurrence occurred over two years of follow-up. Results of our literature review showed lower recurrence and complication rates of the NTVA compared to other surgical modalities.The NTVA is potentially efficient, reliable, and safe for managing CC and cystic-dominant craniopharyngiomas, with low recurrence and complication rates compared to microsurgery and Ommaya reservoir insertion. Future randomized clinical studies comparing the various treatment modalities of CC are needed to solidify these conclusions.

Neuroendoscopic treatment of giant cystic craniopharyngioma in the foramen magnum: report of two cases

Pediatric craniopharyngioma is typically characterized by cystic changes and calcifications. It can grow from the suprasellar area to the posterior fossa (4%). This work reports that it is very rare for craniopharyngioma to grow from the suprasellar area to or beyond the level of the foramen magnum. Twelve patients with this disease have undergone one or several microsurgeries, and the microsurgical approaches are different. Among them, two cases died, and most of the remaining patients had certain complications such as endocrine dysfunction, nerve palsy, and subdural effusion. We treated two patients whose tumors had grown to the level of the foramen magnum, one of which reached C2 levels. Both cases were treated with a neuroendoscopy. There were no deaths and no complications. Our cases are the longest follow-up of this type of craniopharyngioma.

Stereotactic cysto-ventricular catheters in craniopharyngiomas: an effective minimally invasive method to improve visual impairment and achieve long-term cyst volume reduction

Craniopharyngiomas are typically located in the sellar region and frequently contain space-occupying cysts. They usually cause visual impairment and endocrine disorders. Due to the high potential morbidity associated with radical resection, several less invasive surgical approaches have been developed. This study investigated stereotactic-guided implantation of cysto-ventricular catheters (CVC) as a new method to reduce and control cystic components. Twelve patients with cystic craniopharyngiomas were treated with CVC in our hospital between 04/2013 and 05/2017. The clinical and radiological data were retrospectively analysed to evaluate safety aspects as well as ophthalmological and endocrine symptoms. The long-term development of tumour and cyst volumes was assessed by volumetry. The median age of our patients was 69.0 years and the median follow-up period was 41.0 months. Volumetric analyses demonstrated a mean reduction of cyst volume of 64.2% after CVC implantation. At last follow-up assessment, there was a mean reduction of cyst volume of 92.0% and total tumour volume of 85.8% after completion of radiotherapy. Visual acuity improved in 90% of affected patients, and visual field defects improved in 70% of affected patients. No patient showed ophthalmological deterioration after surgery, and endocrine disorders remained stable. Stereotactic implantation of CVC proved to be a safe minimally invasive method for the long-term reduction of cystic components with improved ophthalmological symptoms. The consequential decrease of total tumour volumes optimised conditions for adjuvant radiotherapy. Given the low surgical morbidity and the effective drainage of tumour cysts, this technique should be considered for the treatment of selected cystic craniopharyngiomas.

Beyond the bipolar disorder diagnosis: Hypothalamus and its network damage in determining neuropsychiatric and Korsakoff-like memory disorders

Craniopharyngiomas (CP's) are hypothalamic tumors often associated with psychological disorders. Nevertheless, its diagnosis is still challenging when psychiatric disorders are not associated with any other neurological symptoms. This single-case study describes a patient with a history of bipolar disorder before a diagnosis of a large CP arising the sellar and suprasellar region was posed. At the time of the present study the patient showed emotional/behavioral disorders and Korsakoff-like amnesia, that completely recovered after surgical resection of the tumor. This is one of those few cases described in literature, who presented cognitive/behavioral disorders because the compression of the diencephalic structures due to CP mass effect. This case offers further evidence on the functional neuroanatomy of the hypothalamus and its pathways.

Endoscopic Transcortical Transventricular Management of Cystic Craniopharyngioma: Outcome Analysis of 32 Cases at a Tertiary Care Center

Background

Microsurgical resection has been considered the gold standard treatment of craniopharyngioma, but lately, it has found less favor due to its morbidity and is being replaced by minimally invasive cyst drainage procedures. We present our experience of transventricular endoscopy and cyst drainage along with its technique and have analyzed its results.

Materials and Methods

Clinical and radiological data of all cystic craniopharyngioma patients treated by transventricular endoscopic cyst drainage and Ommaya placement were retrieved and analyzed.

Results

Thirty-two patients underwent endoscopic cyst drainage during the study period. All patients had immediate clinical and radiological improvement. No significant complications were seen. All patients underwent adjuvant radiotherapy and six patients (18.7%) showed recurrence. Three patients died in the follow-up period.

Conclusions

Endoscopic transcortical transventricular cyst drainage with Ommaya reservoir along with adjuvant radiotherapy is a simple, safe, and effective treatment modality.

Utility of Interval Imaging During Focused Radiation Therapy for Residual Cystic Craniopharyngiomas

BACKGROUND

In the present study, we investigated the changes in cyst volume detected on interval computed tomography (CT) in patients undergoing radiation therapy (RT) for residual cystic craniopharyngioma after surgery.

METHODS

We performed a retrospective analysis of CT scans performed halfway during the course of RT for residual cystic craniopharyngioma from January 2005 to January 2018 to assess the incidence of cyst expansion requiring additional intervention. The possible risk factors for cyst expansion during RT were also analyzed.

RESULTS

A total of 33 patients (23 males) with a median age of 15 years (interquartile range 8-21 years) who had undergone surgical excision (n = 30) or aspiration (n = 3) of cystic craniopharyngiomas, followed by stereotactic (n = 25) or conformal (n = 8) RT were included. The extent of reduction in tumor volume after surgery was 66.5% ± 17.9% (range, 20.6%-88.9%). Of the 33 patients, 6 (18.2%) experienced a median increase in cyst volume of 11.1 mL (interquartile range, 9.1-12.1 mL; range, 6.3-40 mL) that was beyond the initial planned target volume (PTV) and necessitated additional intervention. Of the 6 patients in whom the cyst showed an increase in volume, 4 underwent cyst aspiration followed by repeat planning of RT and 2 underwent repeat planning of RT alone without additional surgical intervention. In 5 of these 6 patients, the increase in cyst volume was asymptomatic. Younger age (P = 0.002) and a larger residual cyst wall (P = 0.009) were risk factors for early cyst expansion.

CONCLUSIONS

Cyst expansion will occur in nearly one fifth of patients with cystic craniopharyngioma during the course of RT. As nearly all these expansions are asymptomatic, interval CT scans midway through RT are essential to avoid geographic miss of the tumor.