Stereotactic Radiation as Salvage Therapy for Recurrent Rathke Cleft Cysts.

BACKGROUND: Rathke cleft cysts (RCCs) are sellar-based cystic lesions that are often found incidentally but occasionally become symptomatic with significant visual and/or endocrine deficits. The standard of treatment is surgery, but rare cases of multiply recurrent RCCs can be refractory to surgical drainage, leading to significant morbidity. OBJECTIVE: To demonstrate the safety and feasibility of fractionated stereotactic radiotherapy (SRT) as salvage therapy in multiply recurrent RCCs refractory to surgical drainage. METHODS: An IRB-approved retrospective review at a single institution was conducted to identify and describe patients with multiply recurrent RCCs refractory to surgical drainage who underwent SRT. RESULTS: From 1994 to 2015, 6 patients (5 female) who underwent SRT for recurrent RCCs were identified. A total of 4 presented with visual deficits, and 2 presented with endocrine dysfunction and severe headaches prior to their initial drainage. All patients had initial postoperative improvement but then developed multiple, symptomatic recurrences. Median number of surgical drainage procedures prior to radiotherapy was 3. A total of 3 patients underwent LINAC-based SRT, and 3 had proton-based SRT. Treatment doses were 45 Gy over 25 fractions (n = 5) and 50.4 Gy over 28 fractions (n = 1). Median follow-up after radiation therapy was 69 mo (range 24-154 mo). In the follow-up period, stabilization of the RCC was achieved, although 2 patients required additional drainage procedures. Only 1 patient developed new hypothyroidism and hypoadrenalism after SRT. CONCLUSION: In rare cases of multiply recurrent RCCs refractory to repeat surgical drainage, stereotactic fractionated radiation therapy is a safe and effective salvage therapy.

Proton beam therapy for malignant transformation of intracranial epidermoid cyst.

We report the first clinical case on the successful use of proton beam therapy in the management of malignant transformation of intracranial epidermoid cyst. A 43-year-old man was initially diagnosed as this disease with left facial paresis, hypesthesia and hypoalgesia in the territories of the trigeminal nerve. After failure of surgical interventions, he was referred to our radiation centre. We performed a postoperative proton beam therapy for treatment. We delivered a total dose of 57 GyE in 31 fractions. He tolerated the treatment well with mild acute toxicities and remained healthy and functional by 2-year follow-up postradiotherapy. No evidence of delayed radiation-induced neurotoxicity was observed.

A quantitative analysis of craniopharyngioma cyst expansion during and after radiation therapy and surgical implications.

OBJECTIVE When complete resection of craniopharyngioma is not achievable or the sequelae are prohibitive, limited surgery and radiation therapy have demonstrated excellent local disease control while minimizing treatment-related sequelae. When residual tissue exists, there is a propensity for further cyst development and expansion during and after radiation therapy. This can result in obstructive hydrocephalus, visual changes, and/or clinical decline. The authors present a quantitative analysis of cyst expansion during and after radiotherapy and examine how it affected subsequent management. METHODS The authors performed an institutional review board-approved retrospective study of patients with histologically confirmed craniopharyngioma treated between 2000 and 2015 with surgery and intensity-modulated radiation therapy (IMRT) at a single institution. Volumetric measurements of cyst contours were generated by radiation oncology treatment planning software postoperatively, during IMRT, and up to 12 months after IMRT. Patient, tumor, and treatment-related variables were collected until the last known follow-up and were analyzed. RESULTS Twenty-seven patients underwent surgery and IMRT. The median total radiation dose was 54 Gy. Of the 27 patients, 11 patients (40.7%) demonstrated cyst expansions within 1 year of IMRT. Of note, all tumors with cyst expansion were radiographically Puget Grade 2. Maximal cyst expansion peaked at 4.27 months following radiation therapy, with a median volume growth of 4.1 cm3 (mean 9.61 cm3) above the postoperative cyst volume. Eight patients experienced spontaneous cyst regression without therapeutic intervention. Three patients experienced MRI-confirmed cyst enlargement during IMRT, all of whom required adaptive planning to ensure adequate coverage of the entire tumor volume. Two of these 3 patients required ventriculoperitoneal shunt placement and additional intervention. One underwent additional resection, and the other had placement of an intracystic catheter for aspiration and delivery of intracystic interferon within 12 months of completing IMRT. All 3 patients now have stable disease. CONCLUSIONS Craniopharyngioma cyst expansion occurred in approximately 40% of the patients during or after radiotherapy. In the majority of patients, cyst expansion was a self-limiting process and did not confer a worse outcome. During radiotherapy, cyst expansion may be apparent on image-guided radiation therapy. Adaptive IMRT planning may be required to ensure that the intended IMRT dose covers the entire tumor and cyst volume. The sequelae of cyst expansion include progressive hydrocephalus, which may be treated with a shunt. For patients with solitary cyst expansion, cyst aspiration and/or intracystic interferon may result in disease control.

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

PURPOSE: Although microsurgery remains the first-line treatment, gross total resection of cystic craniopharyngeomas (CP) is associated with significant morbidity and mortality and the addition of external irradiation to subtotal resection proves to achieve similar tumor control. However, concern regarding long-term morbidity associated with external irradiation in children still remains. With this retrospective analysis, the authors emphasize intracavitary brachytherapy using phosphorus-32 (P-32) as a treatment option for children with cystic CP. PATIENTS AND METHODS: Between 1992 and 2009, 17 children (median age 15.4 years; range 7-18 years) with cystic CP underwent intracavitary brachytherapy using P-32. Eleven patients were treated for recurrent tumor cysts; 6 patients were treated primarily. MR imaging revealed solitary cysts in 7 patients; 10 patients had mixed solid-cystic lesions (median tumor volume 11.1 ml; range 0.5-78.9 ml). The median follow-up time was 61.9 months (range 16.9-196.6 months). RESULTS: Local cyst control could be achieved in 14 patients (82 %). Three patients showed progression of the treated cystic formation (in-field progression) after a median time of 8.3 months (range 5.3-10.3 months), which led to subsequent interventions. The development of new, defined cysts and progression of solid tumor parts (out-of-field progression) occurred in 5 patients and led to additional interventions in 4 cases. There was neither surgery-related permanent morbidity nor mortality in this study. The overall progression-free survival was 75, 63, and 52 % after 1, 3, and 5 years, respectively. CONCLUSION: Intracavitary brachytherapy using P-32 represents a safe and effective treatment option for children harboring cystic CP, even as primary treatment. However, P-32 does not clearly affect growth of solid tumor parts or the development of new cystic formations.

Quiste glioependimario congenito: reporte de caso / Glioependymal congenital cyst: case report

El Quiste Glioependimario es un tumor extremadamente raro y excepcionalmente pocos casos han sido reportados; se caracterizan por una cavidad cerrada, con una capa de tejido de epitelio ependimario o una mezcla de tejido ependimario y epitelio coloideo, con un lumen relleno por líquido cefalorraquídeo. Presentamos el caso de un paciente manejado en el servicio de neurocirugía de la Universidad de Cartagena con esta patología.

Primary cystic germinoma originating from the midbrain.

A primary intracranial germinoma that involves the midbrain is rare. We describe an unusual case of primary cystic germinoma originating from the midbrain. A 29-year-old man presented with diplopia, and his MRI showed a cystic, ring-like enhanced lesion in the thalamo-mesencephalic junction. Open biopsy was performed and the diagnosis of germinoma was based upon the histopathological findings. Following chemotherapy and radiotherapy, the symptoms improved and the tumor disappeared. We propose that primary intracranial germinoma should be included in the differential diagnosis of midbrain tumors, because early diagnosis and appropriate treatment for midbrain germinoma improves clinical outcome.

Rupture of brainstem cyst with clinical benefit after head injury. Case report.

The authors report an interesting case of the rupture of a brainstem cyst following blunt head trauma. They discuss the case, review reports of similar events, and suggest a possible mechanism by which the cyst could have resolved without surgery.

Re-evaluation of the dose to the cyst wall in P-32 radiocolloid treatments of cystic brain tumors using the dose-point-kernel and Monte Carlo methods.

Intracavity instillation of beta-emitting colloid pharmaceuticals is a common technique used to treat cystic brain tumors. Most of the dosimetric calculations that have been reported in the literature for this problem are based on empirical formulas derived by Loevinger. Concentration of P-32 radiolabeled solution for the delivery of a prescribed dose (200 Gy to the cyst wall) has been published previously using this formalism in what we refer to as a standard nomogram. The calculations using the Loevinger formulas for calculating the P-32 activity necessary to achieve 200 Gy at the cyst wall is re-evaluated and compared to numerically computed results based on full Monte Carlo simulations (EGSnrc) and the dose-point-kernel (DPK) integration method. For cyst diameters greater than 1 cm, the new calculations agree well with previously published results (the standard nomogram) to within a few percents. However, for cyst diameters of less than 1 cm, it is shown that the standard nomogram results underestimate the therapeutic activity by a factor of approximately 3 for very small diameters (approximately 0.2 cm). New tables based on our calculations are presented and the sources of discrepancies are identified. It is concluded that the new set of data based on our calculations should replace the standard nomogram to administer accurately the target dose to the cyst wall for the smaller diameter cysts (< 1 cm).

Dosimetry for radiocolloid therapy of cystic craniopharyngiomas.

The dosimetry for radiocolloid therapy of cystic craniopharyngiomas is investigated. Analytical calculations based on the Loevinger and the Berger formulas for electrons and photons, respectively, are compared with Monte Carlo simulations. The role of the material of which the colloid introduced inside the craniopharyngioma is made of as well as that forming the cyst wall is analyzed. It is found that the analytical approaches provide a very good description of the simulated data in the conditions where they can be applied (i.e., in the case of a uniform and infinite homogeneous medium). However, the consideration of the different materials and interfaces produces a strong reduction of the dose delivered to the cyst wall in relation to that predicted by the Loevinger and the Berger formulas.

Successful low-dose intracavitary irradiation of a Rathke's cleft cyst with colloidal rhenium-186.

Symptomatic recurrence of an histologically verified intra- and suprasellar Rathke's cleft cyst (RCC) was observed 4 months following transsphenoidal microsurgery. The space-occupying cyst was treated by endocavitary irradiation with colloidal rhenium-186 via a previously implanted catheter with an attached subcutaneous reservoir. The calculated dose of 4.4 Gy was able to stop the production of cyst fluid. Follow-up after intracavitary irradiation extends over 13 months. The cyst, with an initial size of 3 x 3 x 4 cm, has been reduced to 1.1 x 1.06 x 1.2 cm. The production of cyst fluid has decreased from 25 - 30 ml within 2 months before treatment to zero. The patient's visual and mental status as well as her quality of life are normal.

Successful management of sellar and suprasellar arachnoid cysts with stereotactic intracavitary irradiation: an expanded report of four cases.

OBJECTIVE: Sellar and suprasellar arachnoid cysts may be asymptomatic or may cause headache, optic nerve compression, endocrine dysfunction, or hydrocephalus. We propose a minimally invasive treatment strategy when intervention is indicated. METHODS: Four patients with sellar and suprasellar arachnoid cysts presented with headache, visual compromise, and endocrine dysfunction. Two of the four patients previously had undergone unsuccessful surgical intervention. The imaging studies of two patients were diagnostic of an arachnoid cyst. RESULTS: All four patients underwent stereotactic intracavitary radiation with cyst regression and symptomatic improvement. In each patient, the optic chiasm was decompressed successfully. There were no complications from the procedure. CONCLUSION: Stereotactic intracavitary irradiation of arachnoid cysts proved to be safe and effective. The procedure obviated the need for open cyst fenestration or shunting.