Total en-bloc spondylectomy through a posterior approach: technique and surgical outcome in thoracic metastases

Acta Neurochirurgica (2018) 160:1373–1376

In 1981, Roy-Camille et al. have firstly reported the total en-bloc spondylectomy (TES) through a posterior approach for cases of malignant spine tumors in order to reduce the local recurrence and to increase the patient’s survival. By then, this surgery has been increasingly gaining recognition. However, it requires a high level of technical ability and knowledge of spinal anatomy, physiology, and biomechanics.

Method Herein, we report the patient’s selection and technique to execute the TES for cases of thoracic metastasis.

Conclusion This surgery is technically demanding so the patient’s selection requires a careful pre-operative evaluation. However, it can be suggested for patients affected by intracompartmental lesions with a good prognosis since the tumor’s progression is “limited” by local barriers as demonstrated by histological studies.

Stabilization of Tumor-Associated Craniovertebral Junction Instability

Neurosurgery 81:251–258, 2017

Whether primary or metastatic, tumors of the craniovertebral junction (CVJ) are rare and challenging.

OBJECTIVE: To examine the surgical indications, operative variables, and outcomes in patients with tumors of the CVJ undergoing occipitocervical (OC) stabilization.

METHODS: A single-institution, retrospective case series was performed from a prospectively maintained spine database. Patients with primary or metastatic tumors of the CVJ who underwent OC stabilization were identified. Out of 46 patients who underwent OC fusion, 39 were for tumor. Paired t-tests and Wilcoxon rank-sum tests were performed to assess for postoperative changes.

RESULTS: Ten patients (26%) harbored primary tumors, and the remaining 29 (74%) had metastatic disease. Of the metastatic patients, 14 had a neurological deficit, 10 had severe neck pain, and 5 were deemed mechanically unstable. Postoperative visual analog pain scoreswere significantly reduced at all 3 follow-up times (P<.001, 95% confidence interval [CI; 3.2, 6.0]; P = .001, 95% CI [2.6, 7.7]; P = .020, 95% CI [0.6, 5.5]). The percentage of patients who were ambulatory and neurologically improved or intact remained stable postoperatively with no significant declines. There were 2 perioperative mortalities (5%), and 13 patients (33%) experienced a major complication.

CONCLUSIONS: In patients with primary or metastatic tumor of the CVJ, OC stabilization using a cervical screw-rod system affixed to a midline-keel buttress plate, with or without posterior decompression, is a reliable method for CVJ stabilization in the oncologic setting. Improvement in pain and preservation of neurological function was seen.

 

Consensus guidelines for postoperative spine SBRT

J Neurosurg Spine 26:299–306, 2017

Although postoperative stereotactic body radiation therapy (SBRT) for spinal metastases is increasingly performed, few guidelines exist for this application. The purpose of this study is to develop consensus guidelines to promote safe and effective treatment for patients with spinal metastases.

METHODS Fifteen radiation oncologists and 5 neurosurgeons, representing 19 centers in 4 countries and having a collective experience of more than 1300 postoperative spine SBRT cases, completed a 19-question survey about postoperative spine SBRT practice. Responses were defined as follows: 1) consensus: selected by ≥ 75% of respondents; 2) predominant: selected by 50% of respondents or more; and 3) controversial: no single response selected by a majority of respondents.

RESULTS Consensus treatment indications included: radioresistant primary, 1–2 levels of adjacent disease, and previous radiation therapy. Contraindications included: involvement of more than 3 contiguous vertebral bodies, ASIA Grade A status (complete spinal cord injury without preservation of motor or sensory function), and postoperative Bilsky Grade 3 residual (cord compression without any CSF around the cord). For treatment planning, co-registration of the preoperative MRI and postoperative T1-weighted MRI (with or without gadolinium) and delineation of the cord on the T2-weighted MRI (and/or CT myelogram in cases of significant hardware artifact) were predominant. Consensus GTV (gross tumor volume) was the postoperative residual tumor based on MRI. Predominant CTV (clinical tumor volume) practice was to include the postoperative bed defined as the entire extent of preoperative tumor, the relevant anatomical compartment and any residual disease. Consensus was achieved with respect to not including the surgical hardware and incision in the CTV. PTV (planning tumor volume) expansion was controversial, ranging from 0 to 2 mm. The spinal cord avoidance structure was predominantly the true cord. Circumferential treatment of the epidural space and margin for paraspinal extension was controversial. Prescription doses and spinal cord tolerances based on clinical scenario, neurological compromise, and prior overlapping treatments were controversial, but reasonable ranges are presented. Fifty percent of those surveyed practiced an integrated boost to areas of residual tumor and density override for hardware within the beam path. Acceptable PTV coverage was controversial, but consensus was achieved with respect to compromising coverage to meet cord constraint and fractionation to improve coverage while meeting cord constraint.

CONCLUSIONS The consensus by spinal radiosurgery experts suggests that postoperative SBRT is indicated for radioresistant primary lesions, disease confined to 1–2 vertebral levels, and/or prior overlapping radiotherapy. The GTV is the postoperative residual tumor, and the CTV is the postoperative bed defined as the entire extent of preoperative tumor and anatomical compartment plus residual disease. Hardware and scar do not need to be included in CTV. While predominant agreement was reached about treatment planning and definition of organs at risk, future investigation will be critical in better understanding areas of controversy, including whether circumferential treatment of the epidural space is necessary, management of paraspinal extension, and the optimal dose fractionation schedules.

Resection of spinal column tumors utilizing image-guided navigation: a multicenter analysis

IG spinal tumor resection.1

Neurosurg Focus 41 (2):E15, 2016

The use of intraoperative stereotactic navigation has become more available in spine surgery. The authors undertook this study to assess the utility of intraoperative CT navigation in the localization of spinal lesions and as an intraoperative tool to guide resection in patients with spinal lesions.

Methods This was a retrospective multicenter study including 50 patients from 2 different institutions who underwent biopsy and/or resection of spinal column tumors using image-guided navigation. Of the 50 cases reviewed, 4 illustrative cases are presented. In addition, the authors provide a description of surgical technique with image guidance.

Results The patient group included 27 male patients and 23 female patients. Their average age was 61 ± 17 years (range 14–87 years). The average operative time (incision to closure) was 311 ± 188 minutes (range 62–865 minutes). The average intraoperative blood loss was 882 ± 1194 ml (range 5–7000 ml). The average length of hospitalization was 10 ± 8.9 days (range 1–36 days). The postoperative complications included 2 deaths (4.0%) and 4 radiculopathies (8%) secondary to tumor burden.

Conclusions: O-arm 3D imaging with stereotactic navigation may be used to localize lesions intraoperatively with real-time dynamic feedback of tumor resection. Stereotactic guidance may augment resection or biopsy of primary and metastatic spinal tumors. It offers reduced radiation exposure to operating room personnel and the ability to use minimally invasive approaches that limit tissue injury. In addition, acquisition of intraoperative CT scans with real-time tracking allows for precise targeting of spinal lesions with minimal dissection.

Separation surgery and postoperative SRS for spinal metastases

Local disease control for spinal metastases following “separation surgery” and adjuvant hypofractionated or high-dose single-fraction stereotactic radiosurgery

J Neurosurg Spine 18:207–214, 2013

Decompression surgery followed by adjuvant radiotherapy is an effective therapy for preservation or recovery of neurological function and achieving durable local disease control in patients suffering from metastatic epidural spinal cord compression (ESCC). The authors examine the outcomes of postoperative image-guided intensity-modulated radiation therapy delivered as single-fraction or hypofractionated stereotactic radiosurgery (SRS) for achieving long-term local tumor control.

Methods. A retrospective chart review identified 186 patients with ESCC from spinal metastases who were treated with surgical decompression, instrumentation, and postoperative radiation delivered as either single-fraction SRS (24 Gy) in 40 patients (21.5%), high-dose hypofractionated SRS (24–30 Gy in 3 fractions) in 37 patients (19.9%), or low-dose hypofractionated SRS (18–36 Gy in 5 or 6 fractions) in 109 patients (58.6%). The relationships between postoperative adjuvant SRS dosing and fractionation, patient characteristics, tumor histology–specific radiosensitivity, grade of ESCC, extent of surgical decompression, response to preoperative radiotherapy, and local tumor control were evaluated by competing risks analysis.

Results. The total cumulative incidence of local progression was 16.4% 1 year after SRS. Multivariate Gray competing risks analysis revealed a significant improvement in local control with high-dose hypofractionated SRS (4.1% cumulative incidence of local progression at 1 year, HR 0.12, p = 0.04) as compared with low-dose hypofractionated SRS (22.6% local progression at 1 year, HR 1). Although univariate analysis demonstrated a trend toward greater risk of local progression for patients in whom preoperative conventional external beam radiation therapy failed (22.2% local progression at 1 year, HR 1.96, p = 0.07) compared with patients who did not receive any preoperative radiotherapy (11.2% local progression at 1 year, HR 1), this association was not confirmed with multivariate analysis. No other variable significantly correlated with progression-free survival, including radiation sensitivity of tumor histology, grade of ESCC, extent of surgical decompression, or patient sex.

Conclusions. Postoperative adjuvant SRS following epidural spinal cord decompression and instrumentation is a safe and effective strategy for establishing durable local tumor control regardless of tumor histology–specific radiosensitivity. Patients who received high-dose hypofractionated SRS demonstrated 1-year local progression rates of less than 5% (95% CI 0%–12.2%), which were superior to the results of low-dose hypofractionated SRS. The local progression rate after singlefraction SRS was less than 10% (95% CI 0%–19.0%).