Stereotactic intracavitary brachytherapy with P-32 for cystic craniopharyngiomas in children

Brachytherapy in craniopharyngiomas: a systematic review and meta-analysis of long-term follow-up

OBJECTIVE

Brachytherapy has been indicated as an alternative option for treating cystic craniopharyngiomas (CPs). The potential benefits of brachytherapy for CPs have not yet been clarified. The purpose of this work was to conduct a meta-analysis to analyze the long-term efficacy and adverse reactions profile of brachytherapy for CPs.

MATERIALS AND METHODS

The relevant databases were searched to collect the clinical trials on brachytherapy in patients with CPs. Included studies were limited to publications in full manuscript form with at least 5-year median follow-up, and adequate reporting of treatment outcomes and adverse reactions data. Stata 12.0 was used for data analysis.

RESULTS

According to the inclusion and exclusion criteria, a total of 6 clinical trials involving 266 patients with CPs were included in this meta-analysis. The minimum average follow-up was 5 years. The results of the meta-analysis showed that 1-year, 2-3 years and 5 years progression free survival rates (PFS) are 75% (95%CI: 66-84%), 62% (95%CI: 52-72%) and 57% (95%CI: 22-92%), respectively. At the last follow-up, less than 16% of patients with visual outcomes worser than baseline in all included studies. While, for endocrine outcomes, less than 32% of patients worser than baseline level.

CONCLUSION

In general, based on the above results, brachytherapy should be considered as a good choice for the treatment of CP.

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.

Adamantinomatous craniopharyngioma: evolution in the management

BACKGROUND

In spite of the continuous progresses in pediatric neurosurgery, adamantinomatous craniopharyngioma (AC) remains a challenging tumor due to its proximity to optic pathways, pituitary gland, hypothalamus, and Willis' circle, which can result in significant endocrine, cognitive, and neurological morbidity after treatment with subsequent impact on the patient's quality of life (QoL). The relevance that QoL has today explains the changes in the management of AC observed over the time. The goal of the present article is to provide a historical background, to show the milestones in the changes of the AC treatment, and to analyze the current main options to manage such a challenging tumor.

MATERIAL AND METHODS

The pertinent literature has been reviewed. Moreover, a comparison between the past and recent personal series is reported.

RESULTS

Three main eras have been identified. The first (named Cushing era) was characterized by the need to realize a harmless surgery and to define the best way to approach AC; the second (microscope era) was characterized by a tremendous technical and technological development, with remarkable results in term of safe tumor resection and control but relatively poor QoL outcomes; and the third one (current period) is characterized by an increasing integration between surgery and adjuvant treatments, with relatively minor tumor control but significant improvement of QoL (comparable overall survival). The authors' experience reflects these changes. Two groups of children were compared: 52 cases (mean follow-up: 17.5 years) belong to the historical series (group 1, 1985-2003, aggressive surgical management) and 41 (mean follow-up: 8.5 years) to the current one (Group 2, 2004-2021, integrated management). No significant differences between the two groups were detected about recurrence rate, surgical mortality, and overall survival. However, Group 2 showed significant lower rates of postoperative panhypopituitarism, obesity, and visual deterioration.

CONCLUSIONS

Radical surgery allows for a good AC control with a low rate of recurrence but high risk of permanent morbidity. Despite the greater number of recurrences and surgeries, the more conservative policy, based on a combination of treatments, seems to provide the same tumor control with a better QoL. The advances in trans-nasal and trans-ventricular endoscopy, in proton therapy and in the management of the AC cyst are the main factors that allowed such an improvement.

Proton therapy and limited surgery for paediatric and adolescent patients with craniopharyngioma (RT2CR): a single-arm, phase 2 study

BACKGROUND

Compared with photon therapy, proton therapy reduces exposure of normal brain tissue in patients with craniopharyngioma, which might reduce cognitive deficits associated with radiotherapy. Because there are known physical differences between the two methods of radiotherapy, we aimed to estimate progression-free survival and overall survival distributions for paediatric and adolescent patients with craniopharyngioma treated with limited surgery and proton therapy, while monitoring for excessive CNS toxicity.

METHODS

In this single-arm, phase 2 study, patients with craniopharyngioma at St Jude Children's Research Hospital (Memphis TN, USA) and University of Florida Health Proton Therapy Institute (Jacksonville, FL, USA) were recruited. Patients were eligible if they were aged 0-21 years at the time of enrolment and had not been treated with previous radiotherapeutic or intracystic therapies. Eligible patients were treated using passively scattered proton beams, 54 Gy (relative biological effect), and a 0·5 cm clinical target volume margin. Surgical treatment was individualised before proton therapy and included no surgery, single procedures with catheter and Ommaya reservoir placement through a burr hole or craniotomy, endoscopic resection, trans-sphenoidal resection, craniotomy, or multiple procedure types. After completing treatment, patients were evaluated clinically and by neuroimaging for tumour progression and evidence of necrosis, vasculopathy, permanent neurological deficits, vision loss, and endocrinopathy. Neurocognitive tests were administered at baseline and once a year for 5 years. Outcomes were compared with a historical cohort treated with surgery and photon therapy. The coprimary endpoints were progression-free survival and overall survival. Progression was defined as an increase in tumour dimensions on successive imaging evaluations more than 2 years after treatment. Survival and safety were also assessed in all patients who received photon therapy and limited surgery. This study is registered with ClinicalTrials.gov, NCT01419067.

FINDINGS

Between Aug 22, 2011, and Jan 19, 2016, 94 patients were enrolled and treated with surgery and proton therapy, of whom 49 (52%) were female, 45 (48%) were male, 62 (66%) were White, 16 (17%) were Black, two (2%) were Asian, and 14 (15%) were other races, and median age was 9·39 years (IQR 6·39-13·38) at the time of radiotherapy. As of data cutoff (Feb 2, 2022), median follow-up was 7·52 years (IQR 6·28-8·53) for patients who did not have progression and 7·62 years (IQR 6·48-8·54) for the full cohort of 94 patients. 3-year progression-free survival was 96·8% (95% CI 90·4-99·0; p=0·89), with progression occurring in three of 94 patients. No deaths occurred at 3 years, such that overall survival was 100%. At 5 years, necrosis had occurred in two (2%) of 94 patients, severe vasculopathy in four (4%), and permanent neurological conditions in three (3%); decline in vision from normal to abnormal occurred in four (7%) of 54 patients with normal vision at baseline. The most common grade 3-4 adverse events were headache (six [6%] of 94 patients), seizure (five [5%]), and vascular disorders (six [6%]). No deaths occurred as of data cutoff.

INTERPRETATION

Proton therapy did not improve survival outcomes in paediatric and adolescent patients with craniopharyngioma compared with a historical cohort, and severe complication rates were similar. However, cognitive outcomes with proton therapy were improved over photon therapy. Children and adolescents treated for craniopharyngioma using limited surgery and post-operative proton therapy have a high rate of tumour control and low rate of severe complications. The outcomes achieved with this treatment represent a new benchmark to which other regimens can be compared.

FUNDING

American Lebanese Syrian Associated Charities, American Cancer Society, the US National Cancer Institute, and Research to Prevent Blindness.

Brachytherapy in paediatric craniopharyngiomas: a systematic review and meta-analysis of recent literature

PURPOSES

Brachytherapy has been indicated as an alternative option for treating cystic craniopharyngiomas. Despite the difficulties regarding the complex nuclear infrastructure and consequent small number of brachytherapy studies, recent discoveries relating tumour characteristics to sensitivity to brachytherapy have stimulated this extensive systematic review and meta-analysis of the recent results aiming to summarise its efficacy and complications.

METHODS

The systematic review was structured using PRISMA statements. The MEDLINE database was systematically reviewed from March 2010 to February 2021 to identify qualified trials dealing with radioisotope brachytherapy in cystic craniopharyngiomas in the paediatric population, emphasising tumour control rates and complications.

RESULTS

A total of 228 individuals were analysed, of which 66 were children. The minimum average follow-up was 5 years. Considering the paediatric trials, partial and complete responses were achieved in 89% of patients with exclusively cystic lesions, compared to 58% in non-exclusively cystic lesions. The former observed progression in 3% of patients, while in the latter, 35% was reported. Visual and endocrine improvement reached 64% and 20%, respectively, in the first group, in contrast to 48% and 7% in the second group, respectively. There were similar results considering the non-exclusive paediatric series, but with less expressive numbers.

CONCLUSION

These results reinforce the positive impact of radioisotope brachytherapy in the treatment of predominant monocystic or multicystic craniopharyngiomas, especially in the paediatric population, grounded by impressive tumour control rates, lower morbidities and single application in the majority of the cases. In the future, specific morphological tumour characteristics might be considered for a more assertive patient selection.

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.

Evaluation of Long-Term Outcomes and Toxicity After Stereotactic Phosphorus-32-Based Intracavitary Brachytherapy in Patients With Cystic Craniopharyngioma

PURPOSE

Interstitial brachytherapy based on phosphorus-32 (P-32) has an established role as a minimally invasive treatment modality for patients with cystic craniopharyngioma. However, reporting on long-term outcomes with toxicity profiles for large cohorts is lacking in the literature. The purpose of this study is therefore to evaluate the long-term visual, endocrinal, and neurocognitive functions in what is the largest patient series having received this treatment to date.

METHODS AND MATERIALS

We retrospectively evaluated 90 patients with cystic craniopharyngiomas who were treated with stereotactic intracavitary brachytherapy between 1998 and 2010. Colloidal activity of injected radioisotope P-32 was based on an even distribution within the tumor. After treatment, patients were followed-up for a minimum of 5 years and over a mean of 121 months (60-192 months) to assess radiographic and clinical responses.

RESULTS

The 90 patients included in our study cohort underwent a total of 108 stereotactic surgical procedures for 129 craniopharyngioma-related cysts. Of the included tumors, 65 (72.2%) were associated with a single cyst, 15 (16.7%) were associated with 2 cysts, and 10 (11.1%) tumors had developed septations with 3 to 4 cysts. Stereotactic cyst puncture and content aspiration were used to drain a mean cyst fluid volume of 21.4 mL (1.0-55.0 mL). Each cyst was then instilled for interstitial brachytherapy with colloidal P-32 solution. Based on radiographic follow-up assessments, 56 cysts (43.4%) showed resolution and/or nonrecurrence, which was classified as a complete response to treatment; 47 cysts (36.4%) showed a partial response; and 5 cysts (3.9%) displayed a stable appearance. Treatment resulted in immediate and clinically significant vision improvement in 54 of 63 (86%) symptomatic patients, and this improvement was maintained. Progression-free survival rates at 5 and 10 years were 95.5% and 84.4%, respectively.

CONCLUSIONS

P-32-based interstitial brachytherapy can play an effective role in managing patients with cystic craniopharyngiomas. It can be considered a valid alternative to surgery in select patients with a favorable toxicity profile and long-term clinical outcomes.

Gliomas, germ cell tumors, and craniopharyngioma

This report summarizes the current multimodality treatment approaches for children with low- and high-grade gliomas, germinoma, and nongerminomatous germ cell tumors, and craniopharyngiomas used in the Children's Oncology Group (COG) and the International Society of Pediatric Oncology (SIOP). Treatment recommendations are provided in the context of historical approaches regarding the roles of surgery, radiation, and chemotherapy. Future research strategies for these tumors in both COG and SIOP are also discussed.

The implication of giant tumor size on surgical resection, oncological, and functional outcomes in craniopharyngioma

OBJECTIVE

Implication of the tumor size on oncological and functional outcomes of craniopharyngioma is inconsistently reported. The aim of this study is to assess the postoperative outcome of giant craniopharyngiomas (> 4 cm in diameter) and to elucidate the impact of tumor size on various outcome parameters and survival.

MATERIAL AND METHODS

Forty-four patients (children aged ≤ 18 years: 25; adults: 16) with giant craniopharyngioma, operated between January 2001 and December 2015, were included in this study. Various outcomes, progression-free survival (PFS) and overall survival (OS) were calculated.

RESULTS

Gross total resection (GTR) was achieved in 17 (39%) and subtotal resection (STR) in 27 (61%) patients. Eleven patients (25%) received radiotherapy (RT) after STR. Postoperatively, new cranial nerve and motor deficits were noted in 12 (27%) and 9 (20%) patients, respectively. Tumor recurrence following GTR and STR without adjuvant RT was diagnosed in 3 (17%), and 5 (38%) patients, respectively. Following STR with RT, one (9%) experienced recurrence. PFS at 5-, and 10- year following GTR, STR, and STR + RT was 80.8%, 45.4%, and 90%, respectively. At 5- and 10- year, OS was 86.5%, 77.9% and 100% following GTR, STR, and STR + RT, respectively. The rate of GTR was significantly lower in patients with giant tumors (39% vs. 62%; Chi-square test, p value 0.008). Postoperatively, neurological deficit (20%), hypopituitarism (95%) and hypothalamic dysfunction (26%) were significantly higher for giant craniopharyngiomas. Hazards of recurrence were not significant between giant and non-giant tumors (hazard ratio 1.86; 95% CI 0.94-3.68; p 0.07). There was no significant difference in OS between the patients with giant and non-giant tumors (log-rank test 2.1; p value 0.14).

CONCLUSION

Tumor size should be considered as an important predictor of the postoperative functional outcome. Although the rate of GTR is less than that of small tumors, the recurrence rate, progression-free survival, and overall survival of the patients with giant tumor are comparable to non-giant tumors.

Phosphorus-32 interstitial radiotherapy for recurrent craniopharyngioma: Expressions of vascular endothelial growth factor and its receptor-2 and imaging features of tumors are associated with tumor radiosensitivity

To investigate the relationship of the expression of vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor-2 (VEGFR-2) and imaging features with the therapeutic efficacy of Phosphorus-32 colloid interstitial radiotherapy in recurrent craniopharyngioma.Thirty-two patients with recurrent craniopharyngioma underwent phosphorus-32 colloid interstitial radiotherapy. The tumor imaging features were classified into 4 types according to the thickness of the cyst wall and signals of the cyst contents as shown by computed tomography (CT) and magnetic resonance imaging (MRI) images. Protein expressions of VEGF and VEGFR-2 in craniopharyngioma tissues were evaluated with immunohistochemistry before radiotherapy. The tumor radiosensitivity was determined at 12 months after the interstitial radiotherapy.VEGF mainly expressed in the tumor cytoplasm, and VEGFR-2 expressed either in vascular endothelial cells or in tumor endothelial cells. VEGF/VEGFR-2 expressions varied significantly in cases sensitive or insensitive to the radiotherapy (VEGF: P = .028; VEGFR-2: P = .017). Tumor imaging features were associated with the therapeutic efficacy of interstitial radiotherapy (P = .000). VEGF expression had no association with the imaging features of tumors (P = .226), but VEGFR-2 expression was associated with the imaging features of tumors (P = .008).Our results confirmed the association among imaging features, VEGFR-2 expressions, and tumor radiosensitivity in craniopharyngiomas. Imaging features and VEGFR-2 expressions may add useful data to the radiosensitive assessment of craniopharyngiomas.

Pathological and Topographical Classification of Craniopharyngiomas: A Literature Review

Craniopharyngiomas (CPs) are clinically relevant tumors of the sellar region and are associated with high morbidity and occasional mortality. There are two different subtypes of CPs that differ clinically and pathologically: adamantinomatous CP and papillary CP. The differential diagnosis is still challenging even with developments in preoperative imaging as several tumors of the sellar/parasellar region share a continuum of clinical characteristics and imaging similarities. Several topographical classifications of CPs have been mentioned in literature, but to date, there has not been a consensus on a standard reference classification system and there is need to a develop such a model.