Tag: CyberKnife

Posted on

Factors Predicting Recurrence After Resection of Clival Chordoma

Clivus chordomas

Neurosurgery 76:179–186, 2015

Clival chordomas frequently recur because of their location and invasiveness.

OBJECTIVE: To investigate clinical, operative, and anatomic factors associated with clival chordoma recurrence.

METHODS: Retrospective review of clival chordomas treated at our center from 1993 to 2013.

RESULTS: Fifty patients (56% male) with median age of 59 years (range, 8-76) were newly diagnosed with clival chordoma of mean diameter 3.3 cm (range, 1.5-6.7). Symptoms included headaches (38%), diplopia (36%), and dysphagia (14%). Procedures included transsphenoidal (n = 34), transoral (n = 4), craniotomy (n = 5), and staged approaches (n = 7). Gross total resection (GTR) rate was 52%, with 83%mean volumetric reduction, values that improved over time.While the lower third of the clivus was the least likely superoinferior zone to contain tumor (upper third = 72%/middle third = 82%/lower third = 42%), it most frequently contained residual tumor (upper third = 33%/middle third = 38%/lower third = 63%; P , .05). Symptom improvement rates were 61% (diplopia) and 53% (headache). Postoperative radiation included proton beam (n = 19), cyberknife (n = 7), intensity-modulated radiation therapy (n = 6), external beam (n = 10), and none (n = 4). At last follow-up of 47 patients, 23 (49%) remain disease-free or have stable residual tumor. Lower third of clivus progressed most after GTR (upper/mid/lower third = 32%/ 41%/75%). In a multivariate Cox proportional hazards model, male gender (hazard ratio [HR] = 1.2/P = .03), subtotal resection (HR = 5.0/P = .02), and the preoperative presence of tumor in the middle third (HR = 1.2/P = .02) and lower third (HR = 1.8/P = .02) of the clivus increased further growth or regrowth, while radiation modality did not.

CONCLUSION: Our findings underscore long-standing support for GTR as reducing chordoma recurrence. The lower third of the clivus frequently harbored residual or recurrent tumor, despite staged approaches providing mediolateral (transcranial 1 endonasal) or superoinferior (endonasal 1 transoral) breadth. There was no benefit of proton-based over photonbased radiation, contradicting conventional presumptions.

Posted on

Multisession Radiosurgery for Optic Nerve Sheath Meningiomas

Neurosurgery 69:1116–1123, 2011 DOI: 10.1227/NEU.0b013e31822932fe
Traditional treatment options for optic nerve sheath meningiomas (ONSMs) include observation, surgery, and radiotherapy, but to date none of these has become the clear treatment of choice.
OBJECTIVE: To evaluate the effectiveness and safety of multisession radiosurgery for ONSMs.
METHODS: From May 2004 to June 2008, 21 patients with ONSMs were treated by radiosurgery using the frameless CyberKnife system. Patient age ranged from 36 to 73 years (mean, 54 years). All patients were treated using multisession radiosurgery, with 5 fractions of 5 Gy each to a total dose of 25 Gy prescribed to the 75% to 85% isodose line. Patients were evaluated for tumor growth control and visual function.
RESULTS: The median pretreatment tumor volume was 2.8 mL (range, 0.3-23 mL). The mean follow-up was 30 months (range, 11-68 months). All patients tolerated treatment well, with only 1 patient in whom a mild optic neuropathy developed (which remitted after systemic steroid therapy). No other acute or late radiation-induced toxicities were observed. No patients showed ONSM progression on follow-up magnetic resonance imaging. Two patients (10%) had a partial response. No patients had worsening of visual function; visual function was stable in 65% and improved in 35% of patients.
CONCLUSION: Multisession radiosurgery for ONSMs was found to be safe and effective. The preliminary results from this study, in terms of growth control, visual function improvement, and toxicity, are quite promising. Further investigations are warranted.

Posted on

The role of radiosurgery in the treatment of craniopharyngiomas

Neurosurg Focus 28 (4):E11, 2010. (DOI: 10.3171/2010.2.FOCUS09311)

The treatment of craniopharyngiomas is composed of an intricate balance of multiple modalities. Resection and radiotherapy have been combined to synergistically control tumor growth while preventing undue harm to crucial neurovascular structures. Although a craniopharyngioma is a benign lesion pathologically, it may induce severe neurological injury due to its location and rate of growth. More recently, the advent of targeted, fractionated radiotherapy has allowed for more aggressive tumor control while reducing the necessity for large resections. Initial studies have demonstrated significant tumor control in patients who are treated with resection combined with radiation therapy, versus surgery alone, with a lower rate of treatment-associated neurological deficits. In this review, a detailed account of the current studies evaluating the role of stereotactic radiosurgery in the management of craniopharyngiomas is presented. The authors also provide a short account of their experience to aid in defining the role of CyberKnife radiosurgery.

Proudly powered by WordPress