Stereotactic intracavitary irradiation of cystic craniopharyngiomas with yttrium-90 isotope

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.

Interstitial radiotherapy using phosphorus-32 for giant posterior fossa cystic craniopharyngiomas

OBJECT

The treatment for giant posterior fossa cystic craniopharyngiomas remains an important challenge in neurosurgery. The authors evaluated the effects of treating 20 patients with giant posterior fossa cystic craniopharyngiomas using phosphorus-32 (P-32) interstitial radiotherapy at their hospital.

METHODS

The patients included 11 boys and 9 girls with an age range of 3 to 168 months. Before treatment, the tumor volumes ranged from 65 to 215 ml. The intracranial pressure was increased in 16 patients, and optic nerve damage had occurred in 18. The patients received P-32 interstitial radiotherapy following stereotactic cyst-fluid aspiration or drainage and were followed up for 7-138 months.

RESULTS

The treatment immediately relieved the intracranial hypertension symptoms in all patients. At the end of follow-up, imaging examinations revealed that the cystic tumors had disappeared, but some residual calcification remained in 12 patients, and had decreased by more than 75% of the initial volume in 8 patients. The damaged optic nerve recovered in 3 cases, improved in 12 cases, remained unchanged in 1 case, and was aggravated in 2 cases. No other severe complications related to surgery or interstitial radiation occurred. During the follow-up period, 7 new cysts appeared in 5 patients who had received additional interstitial radiotherapies with a dose of P-32 that was calculated using the same formula as for the initial treatment. The new tumors then disappeared in 2 patients, significantly shrank in 2 patients, and progressed in 1 patient.

CONCLUSIONS

For treating giant posterior fossa cystic craniopharyngiomas, P-32 interstitial radiation after stereotactic cyst-fluid aspiration or drainage can achieve a high tumor control rate and has relatively satisfactory clinical effects and quality of life outcomes with few complications.

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.

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

OBJECT

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Radionuclides delivery systems for nuclear imaging and radiotherapy of cancer

The recent developments of nuclear medicine in oncology have involved numerous investigations of novel specific tumor-targeting radiopharmaceuticals as a major area of interest for both cancer imaging and therapy. The current progress in pharmaceutical nanotechnology field has been exploited in the design of tumor-targeting nanoscale and microscale carriers being able to deliver radionuclides in a selective manner to improve the outcome of cancer diagnosis and treatment. These carriers include chiefly, among others, liposomes, microparticles, nanoparticles, micelles, dendrimers and hydrogels. Furthermore, combining the more recent nuclear imaging multimodalities which provide high sensitivity and anatomical resolution such as PET/CT (positron emission tomography/computed tomography) and SPECT/CT (combined single photon emission computed tomography/computed tomography system) with the use of these specific tumor-targeting carriers constitutes a promising rally which will, hopefully in the near future, allow for earlier tumor detection, better treatment planning and more powerful therapy. In this review, we highlight the use, limitations, advantages and possible improvements of different nano- and microcarriers as potential vehicles for radionuclides delivery in cancer nuclear imaging and radiotherapy.

Craniopharyngioma: modern concepts in pathogenesis and treatment

PURPOSE OF REVIEW

Craniopharyngioma is a benign tumour. Its tendency to recur after excision and the high surgical risk due to involvement of the most vital structures of the brain mean that alternatives to radical surgery should be considered, namely limited surgical procedures followed by radiotherapy. Since both options present inherent risks, optimal craniopharyngioma treatment remains controversial. This paper aims to critically review the recent literature on craniopharyngioma.

RECENT FINDINGS

The management of children with craniopharyngioma has benefited from concerted efforts by national and international groups to improve outcome and reduce morbidity. From the current literature it is evident that there is a trend to better integrate all treatment modalities available, tailoring therapies to specific risk factors. Modern imaging and new surgical and radiotherapy techniques are increasing the possibility of cure. Biological markers are under investigation and this will increase our knowledge on craniopharyngioma.

SUMMARY

Studies on treatment, biology and pathogenesis of craniopharyngioma, available in the current literature, grew considerably in the last year. Although a consensus has not been reached on all aspects of this complex disease, there is a trend in the field to move quickly towards a better understanding of the disease to improve treatment strategies and to produce clinical cooperative trials.