Sacral tumors represent a small subset of spinal lesions and typically include chordomas, metastases, other primary bone tumors, and benign schwannomas. Resection is the standard treatment for many sacral tumors, but many types of sacral lesions have the potential for recurrence after excision. In these cases, adjuvant radiotherapy is often beneficial. Although conventional radiotherapy plays an important role in the management of spinal lesions, the radiation doses required for adequate local control of many sacral lesions generally exceed the tolerance doses of normal tissues, thus limiting its definitive role in the management of sacral tumors. Recent advances in the field of stereotactic radio-surgery have allowed precise targeting of the sacrum. In this report the authors review the use of these two forms of radiation treatment and their role in managing sacral tumors.
Iris C. Gibbs and Steven D. Chang
Steven D. Chang and Gordon T. Sakamoto
Hemangiopericytomas represent a small subset of meningeal tumors. Despite their relatively uncommon nature, they are aggressive tumors known for recurrence. Resection is the standard treatment in most, although regrowth and metastases are common even after resection. The authors evaluate the role of stereotactic radiosurgery in the treatment of recurrent hemangiopericytomas.
In a review of the Stanford radiosurgery patient database between 1989 and 2002, the authors found eight patients with recurrent hemangiopericytoma who underwent stereotactic radiosurgery. The mean age of this population was 45.1 years (range 24–67 years). All patients had been previously treated with resection, and five patients (63%) had undergone conventional radiotherapy. The mean radiosurgery dose to the tumor margin was 20.5 Gy (range 16–24 Gy). The mean clinical and radiographic follow-up period was 44 months (range 8–77 months). Of the eight tumors treated with radiosurgery, six decreased in size and two ultimately progressed. There were no radiosurgery-related complications.
Stereotactic radiosurgery of hemangiopericytomas can result in increased tumor control and should be considered as a treatment option for patients in whom the diagnosis has been established and in whom residual tumor is demonstrated postoperatively. Close clinical and radiographic follow-up evaluation is necessary in this patient population because of the high rate of local recurrence and distant metastases.
Omar Choudhri and Steven D. Chang
Craniopharyngiomas are benign, partly cystic epithelial tumors that can rarely occur in a retrochiasmatic location with involvement of the third ventricle. The lamina terminalis is an important neurosurgical corridor to these craniopharyngiomas in the anterior portion of the third ventricle. We present a video case of a large midline suprasellar and third ventricular craniopharyngioma in a 32-year-old male with visual disturbances. The tumor was approached with a subfrontal translamina terminalis exposure, and a gross-total resection of the tumor was achieved. This surgery involved working through a lamina terminalis fenestration around the optic nerve, optic chiasm, optic tracts, and the anterior communicating artery complex. This video illustrates the techniques employed in performing a transbasal anterior skull base approach to the third ventricle and demonstrates vivid surgical anatomy of neurovascular structures around the lamina terminalis.
The video can be found here: https://youtu.be/fCYMgx8SnKs.
Omar Choudhri and Steven D. Chang
Pinealoblastomas are WHO grade IV tumors of the pineal region and comprise up to 50% of all pineal parenchymal tumors. They are highly aggressive tumors that spread along the craniospinal axis and are most commonly seen in children. The standard of care involves maximal surgical resection and chemoradiation following tissue diagnosis. We present the rare case of a large pinealoblastoma in an 18-year-old girl who presented with headaches and Parinaud's syndrome from tectal compression. An attempt was made at endoscopic transventricular biopsy of the tumor at an outside hospital, but it was aborted given bleeding at the biopsy site. We performed a supracerebellar infratentorial approach in a sitting position to achieve a gross-total resection of the tumor. This video case illustrates techniques for setting up a sitting craniotomy and approaching a previously biopsied hemorrhagic pinealoblastoma. The venous conglomerate at the tentorial incisura was found to be enveloped by the tumor and a thickened arachnoid scar. Surgical anatomy of the third ventricle and the pineal region is illustrated in this case through the process of surgical dissection and tumor resection.
The video can be found here: https://youtu.be/CzB0lFQ7AyI.
Stephen I. Ryu, Daniel H. Kim and Steven D. Chang
The optimal treatment for intramedullary spinal tumors is controversial, because both resection and conventional radiation therapy are associated with potential morbidity. Stereotactic radiosurgery can theoretically deliver highly conformal, high-dose radiation to surgically untreatable lesions while simultaneously mitigating radiation exposure to large portions of the spinal cord. The purpose of this study was to evaluate the authors' initial experience with frameless stereotactic radiosurgery for intramedullary spinal tumors.
Between 1998 and 2003, 10 intramedullary spinal tumors were treated with stereotactic radiosurgery at the authors' institution. Seven hemangioblastomas and three ependymomas were treated in four men and three women. These patients either had recurrent tumors, had undergone several previous surgeries, had medical contraindications to surgery, or had declined open resection. Conformal treatment planning delivered a prescribed dose of 1800 to 2500 cGy (mean 2100 cGy) to the lesions in one to three stages. No significant treatment-related complications have been recorded. The mean radiographic and clinical follow-up duration was 12 months (range 1–24 months). One ependymoma and two hemangioblastomas were smaller on follow-up neuroimaging. The remaining tumors were stable at the time of follow-up imaging.
Stereotactic radiosurgery for intramedullary spinal tumors is feasible and safe in selected cases and may prove to be another therapeutic option for these challenging lesions.
Steven D. Chang and John R. Adler Jr.
The management of patients with multiple brain metastases remains a difficult challenge for neurosurgeons. This patient population has a poor prognosis when compared with those harboring a solitary brain metastasis, and historically treatment has generally consisted of administering whole-brain radiotherapy once the diagnosis of multiple brain metastases is made. Resection can be useful in a subset of patients with multiple metastases in whom one or two of the lesions are symptomatic, as this may provide rapid reduction of mass effect and edema. Furthermore, the authors of recent studies have shown that stereotactic radiosurgery can be used in certain patients with multiple brain metastases as part of the treatment regimen. In this review the authors outline the treatment options and indications as well as a management strategy for the treatment of patients with multiple brain metastases.
Tej D. Azad, Rogelio Esparza, Navjot Chaudhary and Steven D. Chang
Metastatic disease to the craniovertebral junction (CVJ) is rare but presents unique management challenges. To date, studies on using stereotactic radiosurgery (SRS) for CVJ metastases have been limited to case reports and small case series. The aim of this analysis was to evaluate the utility of SRS in the management of these secondary lesions.
Clinical and radiological information from the charts of 25 patients with metastatic disease of the CVJ who were treated with SRS between 2005 and 2013 at the Stanford CyberKnife Center were retrospectively reviewed.
Seven male and 18 female patients with a median age of 58 years (range 34–94 years) were identified. The most common primary tumors were breast cancer (n = 5) and non-small cell lung cancer (n = 5), and the most frequent symptom was neck pain (n = 17). The average tumor volume treated was 15.9 cm3 (range 0.16–54.1 cm3), with a mean marginal radiation dose of 20.3 Gy (range 15–25.5 Gy). The median follow-up was 18 months (range 1–81 months), though 1 patient was lost to follow-up.
SRS provided radiographic tumor stability in over 80% of patients, offered pain alleviation in nearly two-thirds of patients, and produced no serious complications. Moreover, SRS preserved spinal stability in all but 1 patient, in whom pre-SRS stability was established. There was no evidence of radiation toxicity in the patient population. Median survival was 28 months (range 2–81 months), with survival of 13.3% at 5 years.
In the absence of unstable pathological fracture and spinal cord compression, metastatic tumors of the CVJ can be safely and effectively treated with SRS. This treatment option offers palliative pain relief and can halt tumor progression with only a low risk of complications or spinal instability.
Mark H. Bilsky, Steven D. Chang, Peter C. Gerszten and Steven Kalkanis
Michael Zhang, Yi-Ren Chen, Steven D. Chang and Anand Veeravagu
Symptomatic vertebral hemangiomas (SVHs) are a very rare pathology that can present with persistent pain or neurological deficits that warrant surgical intervention. Given the relative rarity and difficulty in assessment, the authors sought to present a dedicated series of SVHs treated using stereotactic radiosurgery (SRS) to provide insight into clinical decision making.
A retrospective review of a single institution's experience with hypofractionated radiosurgery for SVH from 2004 to 2011 was conducted to determine the clinical and radiographic outcomes following SRS treatment. The authors report and analyze the treatment course of 5 patients with 7 lesions, 2 of which were treated primarily by SRS.
Of the 5 patients studied, 4 presented with a chief complaint of pain refractory to conservative measures. Three patients reported dysesthesias, and 2 reported upper-extremity weakness. Following radiosurgery, 4 of 5 patients exhibited improvement in their primary symptoms (3 for pain and 1 for weakness), achieving a clinical response after a mean period of 1 year. In 2 cases there was 20%–40% reduction in lesion size in the most responsive dimension as noted on images. All treatments were well tolerated.
SRS for SVH is a safe and feasible treatment strategy, comparable to prior radiotherapy studies, and in select cases may successfully confer delayed decompressive effects. Additional investigation will determine future patient selection and how conformal SRS treatment can best be administered.
Steven D. Chang, Joseph Poen, Steven L. Hancock, David P. Martin and John R. Adler Jr.
✓ Two cases of acute hearing loss are reported following fractionated stereotactic radiosurgery for acoustic neuroma. Both patients had neurofibromatosis type 2 and were treated with a peripheral tumor dose of 21 Gy delivered in three fractions (7 Gy each) with a minimum interfraction interval of 10 hours. One patient who had previously undergone surgical resection of the treated tumor presented with only rudimentary hearing in the treated ear secondary to an abrupt decrease in hearing prior to treatment. That patient reported total loss of hearing before complete delivery of the third fraction. The second patient had moderately impaired hearing prior to treatment; however, within 10 hours after delivery of the final fraction, he lost all hearing. Both patients showed no improvement in response to glucocorticoid therapy. Possible explanations for this phenomenon are presented.