Category: Pituitary

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Tolerance of the Optic Apparatus in Single-Fraction Irradiation Using Stereotactic Radiosurgery: Evaluation in 100 Patients With Craniopharyngioma

Neurosurgery 66:688-695, 2010. DOI: 10.1227/01.NEU.0000367554.96981.26

OBJECTIVE: To determine the limiting dose to the optic apparatus in single-fraction irradiation in patients with craniopharyngioma treated with gamma knife radiosurgery (GKRS).

METHODS: One hundred patients with 109 craniopharyngiomas treated with GKRS were evaluated with a median follow-up period of 68 months. Tumor volume varied from 0.1 to 36.0 (median, 3.3) cm3. Marginal doses varied from 10 to 18 (median, 11.4) Gy. Maximum dose to any part of the optic apparatus varied from 2 to 18 (median, 10) Gy.

RESULTS: The actuarial 5- and 10-year overall rates of survival of tumor progression after GKRS were 93% and 88%, respectively. Similarly, the actuarial 5- and 10-year progressionfree survival rates were 62% and 52%, respectively. Among 94 patients in whom visual function was evaluable after GKRS, only 3 patients developed radiation-induced optic neuropathy, indicating an overall Kaplan-Meier radiation-induced optic neuropathy rate of 5%. Of these patients, 2 received 15 Gy or greater to the optic apparatus. Another patient who received 8 Gy or less had undergone previous fractionated radiation therapy with a biologically effective dose of 60 Gy.

CONCLUSION: The optic apparatus seems to be more tolerant of irradiation than previously thought. Careful dose planning is essential, particularly in patients who underwent prior external beam radiation therapy.

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Extensions of the Sphenoid Sinus: A New Classification

Neurosurgery. 66(4):797-816, April 2010. doi: 10.1227/01.NEU.0000367619.24800.B1

The transsphenoidal approach has been extended in recent years from tumors of the sellar region to lesions involving other areas bordering the sphenoid sinus including the cavernous sinus, Meckel’s cave, middle cranial fossa, planum sphenoidal, suprasellar region, and clivus. The goal of this study was to examine various pneumatized extensions of the sphenoid sinus that may facilitate extended approaches directed through the sinus.

METHODS: The sphenoid sinus and its surrounding structures were examined in 18 cadaver heads, and the results were correlated with the findings from 100 computed tomography images of the sinus. The sellar type of the sphenoid sinus in which the pneumatization extended beyond the anterior sellar wall was further classified according to the various extensions of the sinus.

RESULTS: The sellar type of the sphenoid sinus was classified into the following 6 basic types based on the direction of pneumatization: sphenoid body, lateral, clival, lesser wing, anterior, and combined. The recesses and prominences, formed by pneumatization of the sinus, act as “windows” opening from the sinus in different areas of the cranial base and may facilitate minimally invasive access to lesions in the corresponding areas.

CONCLUSION: The variations in the extensions of pneumatization of the sphenoid sinus may facilitate entry into areas bordering the sphenoid sinus and play a role in the selection of a surgical approach to lesions bordering the sinus.

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Early outcomes of endoscopic transsphenoidal surgery for adult craniopharyngiomas

Neurosurg Focus 28 (4):E9, 2010. (DOI: 10.3171/2010.1.FOCUS09319)

Although the transsphenoidal approach for subdiaphragmatic craniopharyngiomas has been performed for many years, there are few reports describing the role of the endoscopic transsphenoidal technique for suprasellar craniopharyngiomas. The purpose of this study was to report the outcomes of the endoscopic transsphenoidal approach for adults with craniopharyngiomas in whom the goal was gross-total resection.

Methods. Twelve patients were identified who were older than 18 years at the time of their pure endoscopic transsphenoidal surgery. Their medical records and imaging studies were retrospectively reviewed.

Results. Gross-total resection was achieved in 42% of cases when assessed by intraoperative impression alone and in 75% when assessed by the first postoperative MR imaging study. However, 83% of patients achieved at least a 95% resection when assessed by both intraoperative impression and the first postoperative MR imaging study. Permanent diabetes insipidus occurred postoperatively in 44% of patients. Six (67%) of 9 patients who had a functioning hypothalamic-pituitary axis preoperatively developed panhypopituitarism after surgery. Visual improvement or normalization occurred in 78% of patients with preoperative visual deficits. Although no patient experienced a postoperative CSF leak, 1 patient was treated for meningitis.

Conclusions. The authors have achieved a high rate of radical resection and symptomatic improvement with the endoscopic transsphenoidal technique for both subdiaphragmatic (sellar/suprasellar) and supradiaphragmatic (suprasellar) craniopharyngiomas. However, this is also associated with a high incidence of new endocrinopathy. Endoscopic assessment of tumor resection may be more sensitive for residual tumor than the first postoperative MR imaging study.

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Intrasellar Ultrasound in Transsphenoidal Surgery: A Novel Technique

Neurosurgery 66:173-186, 2010. doi: 10.1227/01.NEU.0000360571.11582.4F

OBJECTIVE: Residual tumor masses are common after transsphenoidal surgery. The risk of a residual mass increases with tumor size and parasellar or suprasellar growth. Transsphenoidal surgery is usually performed without image guidance. We aimed to investigate a new technical solution developed for intraoperative ultrasound imaging during transsphenoidal surgery, with respect to potential clinical use and the ability to identify neuroanatomy and tumor.

METHODS: In 9 patients with pituitary macroadenomas, intrasphenoidal and intrasellar ultrasound was assessed during transsphenoidal operations. Ultrasound B-mode, power-Doppler and color-Doppler images were acquired using a small prototype linear array, side-looking probe. The long probe tip measures only 3 × 4 mm. We present images and discuss the potential of intrasphenoidal and intrasellar and ultrasound in transsphenoidal surgery.

RESULTS: We present 2-dimensional, high-resolution ultrasound images. A small side-looking, high-frequency ultrasound probe can be used to ensure orientation in the midline for the surgical approach to identify important neurovascular structures to be avoided during surgery and for resection control and identification of normal pituitary tissue. The image resolution is far better than what can be achieved with current clinical magnetic resonance imaging technology.

CONCLUSION: We believe that the concept of intrasellar ultrasound can be further developed to become a flexible and useful tool in transsphenoidal surgery.

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Extended transsphenoidal approach for pituitary adenomas invading the anterior cranial base, cavernous sinus, and clivus: a single-center experience with 126 consecutive cases

J Neurosurg 112:108–117, 2010. (DOI: 10.3171/2009.3.JNS0929)

The standard transsphenoidal approach has been successfully used to resect most pituitary adenomas. However, as a result of the limited exposure provided by this procedure, complete surgical removal of pituitary adenomas with parasellar or retrosellar extension remains problematic. By additional bone removal of the cranial base, the extended transsphenoidal approach provides better exposure to the parasellar and clival region compared with the standard approach. The authors describe their surgical experience with the extended transsphenoidal approach to remove pituitary adenomas invading the anterior cranial base, cavernous sinus (CS), and clivus. Methods. Retrospective analysis was performed in 126 patients with pituitary adenomas that were surgically treated via the extended transsphenoidal approach between September 1999 and March 2008. There were 55 male and 71 female patients with a mean age of 43.4 years (range 12–75 years). There were 82 cases of macroadenoma and 44 cases of giant adenoma. Results. Gross-total resection was achieved in 78 patients (61.9%), subtotal resection in 43 (34.1%), and partial resection in 5 (4%). Postoperative complications included transient cerebrospinal rhinorrhea (7 cases), incomplete cranial nerve palsy (5), panhypopituitarism (5), internal carotid artery injury (2), monocular blindness (2), permanent diabetes insipidus (1), and perforation of the nasal septum (2). No intraoperative or postoperative death was observed. Conclusions. The extended transsphenoidal approach provides excellent exposure to pituitary adenomas invading the anterior cranial base, CS, and clivus. This approach enhances the degree of tumor resection and keeps postoperative complications relatively low. However, radical resection of tumors that are firm, highly invasive to the CS, or invading multidirectionally remains a big challenge. This procedure not only allows better visualization of the tumor and the neurovascular structures but also provides significant working space under the microscope, which facilitates intraoperative manipulation. Preoperative imaging studies and new techniques such as the neuronavigation system and the endoscope improve the efficacy and safety of tumor resection.


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Adult craniopharyngiomas: surgical results with a special focus on endocrinological outcomes and recurrence according to pituitary stalk preservation

DOI: 10.3171/2008.10.JNS0880

The aim of this study was to evaluate the results of surgical treatment of adult craniopharyngioma with a special focus on the endocrinological outcomes and tumor recurrence in cases of pituitary preservation.

Methods: Between 1993 and February 2008, 41 patients underwent 47 surgical procedures for craniopharyngioma. The male/female ratio was 26:15 and the median age was 45.8 years (range 17–65 years). The median follow-up period was 10.56 years (range 6.2–14.9 years). Patients presented with visual disturbance before 30 (63.8%) of 47 procedures and with endocrinological disturbance before 12 (26%) procedures. Surgery was performed via a subfrontal/pterional approach in 31 procedures (66%), bifrontal interhemispheric in 6 (12.8%), transcallosal/transventricular in 5 (10.6%), combined in 1 (2.1%), and transsphenoidal in 4 (8.5%). The tumor was totally removed in 36 procedures (76.6%), subtotally in 10 (21.3%), and partially in 1 (2.1%).

Results: Postoperatively, the rates of visual improvement and aggravation were 50 and 33.3%, respectively. Of 24 patients in whom the pituitary stalk was preserved, complete hormone replacement was needed in 14 (58.3%), partial replacement in 2 (8.3%), and no replacement in 8 (33.3%). The rate of tumor recurrence was 24.4%. The recurrence-free survival rate was significantly different between patients in whom complete tumor resection was accomplished and those in whom tumor resection was incomplete. Stalk preservation did not affect the recurrence-free survival rate. The morbidity and mortality rates were 8.5 and 2.1%, respectively.

Conclusions: The pituitary stalk must be preserved with maximal tumor resection whenever possible to increase the chance of intact anterior pituitary function being maintained. The results of the present study show that pituitary stalk preservation may not be related to increased recurrence rates.

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Residual nonfunctioning pituitary adenomas: prognostic value of MIB-1 labeling index for tumor progression

J Neurosurg 111 (3)563-571. DOI: 10.3171/2008.4.17517

In residual nonfunctioning pituitary adenomas, reliable prognostic parameters indicating probability of tumor progression are needed. The Ki 67 expression/MIB-1 labeling index (LI) is considered to be a promising candidate factor. The aim in the present study was to analyze the clinical usefulness of MIB-1 LI for prognosis of tumor progression.

Methods: The authors studied a cohort of 92 patients with nonfunctioning pituitary adenomas. Based on sequential postoperative MR images, patients were classified as tumor free (51 patients) or as harboring residual tumor (41 individuals). The residual tumor group was further subdivided in groups with stable residual tumors (14 patients) or progressive residual tumors (27 patients). The MIB-1 LI was assessed in tumor specimens obtained in all patients, and statistical comparisons of MIB-1 LI of the various subgroups were performed.

Results: The authors found no significant difference of MIB-1 LI in the residual tumor group compared with the tumor-free group. However, MIB-1 LI was significantly higher in the progressive residual tumor group, compared with the stable residual tumor group. Additionally, the time period to second surgery was significantly shorter in residual adenomas showing an MIB-1 LI > 3%.

Conclusions: The data indicate that MIB-1 LI in nonfunctioning pituitary adenomas is a clinically useful prognostic parameter indicating probability of progression of postoperative tumor remnants. The MIB-1 LI may be helpful in decisions of postoperative disease management (for example, frequency of radiographic intervals, planning for reoperation, radiotherapy, and/or radiosurgery).

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