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  • 8/17/2019 Management of Spinal Metastases

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    Management of Spinal Metastases

    Enric Cáceres Palou

    Contents

    General Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4310

    Aetiology and Classification . . . . . . . . . . . . . . . . . . . . . . 4311

    Applied Biomechanics, Pathology and Basic

    Science . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4311

    Metastatic Tumour Cells .. .. .. .. .. .. .. .. .. .. .. .. .. . 4311

    Angiogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4312

    Invasion of Soft Tissue .. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4313

    Bone Resorption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4313

    Mechanism of Spinal Cord Compression .. .. . . .. . . 4314

    Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4314

    PET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4315Treatment of Spinal Metastases and Indications for

    Surgery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4318

    Steroids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4318

    Chemotherapy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4318

    Radiation Therapy .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4318

    Surgical Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4318

    Indications and Contra-Indications . . .. . . . .. . . . . . . . 4319

    Operative Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4319

    Vertebroplasty and Kyphoplasty . .. .. .. .. .. .. .. .. .. 4319

    Decompression and Instrumentation . . . . . . . . . . . . . . . 4319

    En Bloc Resection .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4322

    Complications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4322

    Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4322

    References . . . . . . . . . . . .. . . . . . . . . . . .. . . . . . . . . . .. . . . . .   4322

    Abstract

    Metastatic spine tumours (MST) cause the lossof the supporting function of the spine through

    vertebral destruction or invade and compress

    the spinal cord or cauda equina. As a result,

    metastatic spine tumour causes severe pain,

    paralysis and decreased of quality of Life

    (QOL). For this reason treatment is primarily

    symptomatic and the major goals in selecting

    therapeutic modalities are to relieve pain,

    prevent paralysis and improve activities OD

    daily living (ADL).Four main circumstances influence MST

    treatment: continuous improving in survival,

    changes in prevalence of the disease, multidis-

    ciplinary dependence and evidence of 

    literature. Mortality rates continue to decrease

    year-by-year for three most common sites in

    men (lung, colorectal and prostate) and in

    women fort breast and colorectal. Around

    1.5 % for men and 0.8 % for women.

    Analysing MST, the multidisciplinarydependence, with different approaches,

    different attitude, especially different world

    literature, medical oncologists, palliative

    care, radiotherapists, epidemiology health

    experts, neurosurgeons and the Orthopaedic

    community means that the interpretation of 

    results and advice to the patient can be

    confusing.

    The optimal management of MST is con-

    troversial, a multidisciplinary approach withaccording to assess neurological and oncolog-

    ical symptoms, mechanical stability and

    E. Cáceres Palou

    Department Hospital Vall d’Hebron, AutonomousUniversity of Barcelona, Barcelona, Spain

    e-mail: [email protected]

    G. Bentley (ed.), European Surgical Orthopaedics and Traumatology,

    DOI 10.1007/978-3-642-34746-7_259,# EFORT 2014

    4309

    mailto:[email protected]:[email protected]

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    extent of systemic disease is the most easily

    understood system of categorizing patient,

    regardless of the specialty. We know this

    approach by NOMS the capital letters of 

    N for Neurological status, O for Oncological

    factors including tumour histology, M for mechanical stability of spine and finally S for 

    Systemic evaluation of the overall extent of 

    disease. These must always be factored in to

    decision-making processes.

    We advise the use a guideline combining the

    Harrington classification (neurological status

    and structural changes), Tokuhashi’s prognostic

    scoring system and Tomita spread. This is the

    modified Harrington classification in five

    classes.In this chapter we discuss the role of con-

    ventional and stereotactic radiotherapy treat-

    ment and the different approach and

    management according to the site of the lesion

    in the cervical or thoracolumbar areas.

    A more specific question is what is the role

    of  en bloc   surgery for metastatic tumours of 

    the spine? We do these procedures in patients

    suffering from single spinal metastases deriv-

    ing from the primary tumour, with a long lifeexpectancy and already treated but we also

    need to include tumour size, location and

    Wenstein Boriani Biagini (WBB) surgical

    score classification in order to know if it’s

    possible to do it. Our conclusion is that there

    is no significant difference of survival time,

    but the local recurrence rate of en bloc resec-

    tion is lower than for debulking.

    Finally, we describe some specific surgical

    procedures in different cases, radiation ther-apy, open surgery with decompression and

    instrumentation, en bloc resection and the cur-

    rent role of percutaneous image-guided verte-

    bral body augmentation.

    Keywords

    Aetiology and Classification    Biomechanics

    and pathology     Diagnosis     Surgical

    indications     Surgical Technique  

    Vertebrectomy and Kyphoplasty 

      Decom-pression and instrumentation    Complications

    General Introduction

    Cancer is the leading cause of death in western

    world having supplanted heart disease in those

    under age 85 since 1999 [1]. Recent data suggesta progressively improving trend in survival.

    Since 1993, the death rate from all cancers com-

    bined has decreased by 1.5 % per year among

    men, and by 0.8 % among women. Mortality

    rates continue to decrease for the three most

    common sites in men (lung, colorectal, and pros-

    tate) and in women for breast and colorectal

    cancer [2 – 4].

    Metastatic disease to the spine is by far the

    most common clinical problem confrontingspine oncologists. Some autopsy data suggest

    that metastases to the spine are present in more

    than 70 % of the patients with the most common

    cancers (breast, lung, and prostate), these data,

    comes from original article by Jaffe [5] but

    could be exaggerated. Other autopsy studies

    have been performed to evaluate the rate of 

    spinal metastasis SM. Spines from 832

    deceased patients with diagnosis of malignant

    neoplasm were studied grossly, microscopi-cally, and radiographically by Wong et al. [6].

    Overall metastases were disclosed in 36 % of 

    patients dying of neoplastic disease. Around

    16 % were occult and not visible on plains

    radiographies. The actual clinical incidence of 

    symptomatic epidural metastases causing spinal

    cord and cauda equina compression is perhaps

    much lower (around 5 %) [7].

    Technological advances during the last two

    decades have greatly expanded the possibilitiesfor treatment in oncology; this progress has

    resulted in newer tools for diagnosis, treatment,

    and follow-up.

    The treatment of metastatic spine disease has

    evolved significantly with the introduction of 

    advanced interventional, surgical and radiation

    techniques. Successful treatment of SM

    accomplishes effective pain palliation, mainte-

    nance or recovery of neurological function and

    ambulation, local durable pain control, spinalstability, and improved quality of life.

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    Multiple guideline-scoring system have been

    describe last two decades but the definitive

    evidence-based-medicine has not yet been

    determined.

    Aetiology and Classification

    The prevalence of primary tumours varies

    according to published reports. Kostuick [8] in

    a summary of 2,748 cases considering only solid

    tumours, breast, lung and prostate compose the

    majority of SM, followed by renal, gastrointesti-

    nal and thyroid carcinomas. In the autopsy stud-

    ies, breast and lung accounted for the most

    frequent primary sites, followed bylymphoreticular malignancies, and pancreas.

    Some SM may occur with no known history of 

    a primary site- Klimo [9] estimates 10 % of 

    metastases ignores the aetiology. The more his-

    tological disclosed primary tumours are lung,

    followed by prostate and kidney [10].

    Besides the aetiology, the SM could be classi-

    fied according to, their localization, the bony

    pattern (lytic or sclerotic or a combination of 

    both) and the neurological signs. Several preoper-ative scoring systems have been proposed to clas-

    sify patients with SM, to obtain prognostic

    evaluation and designed a correspondent treatment.

    Karnosky [11] score, is a functional to assess

    the general condition of the patient with meta-

    static disease, and could be used evaluating the

    postoperative result of the surgical treatment. It’s

    a subjective score with 100 points for abnormal,

    healthy status to 0 for dead or 10: fatal processes,

    progressing rapidly; moribund.Tokuhasi [12] proposed in 1990 a system to

    assess the prognosis of metastatic spine tumours

    using six parameters (Table   1) and in 2005

    revised his system, increasing the role of the

    primary site of cancer, with improvement in

    prognosis prediction from 63 % to 82 %.

    Tomita [13] proposed in 2001 a three prog-

    nostic factor score for SM (Table 2) Finally more

    in relation with neurological status the SM could

    be classified in five categories followingHarrintong [14] classification score (Table 3).

    Applied Biomechanics, Pathologyand Basic Science

    Metastatic Tumour Cells

    Although the genetic basis of tumours are varied,

    the steps or stages in the development and rele-

    vant clinical metastases are very similar for all

    tumours. Because the tumour cells metastasize,

    the malignant cells that have primary access tothe vascular system and travel through the

    Table 1   Tokuhasi score. Tokuhasi [12] proposed in 1990a system to assess the prognosis of metastatic spine

    tumours using six parameters and in 2005 revised his

    system, increasing the role of the primary site of cancer 

    Characteristic Score

    General condition (performance status)Poor (PS 10–40 %) 0

    Moderate (PS 50–70 %) 1

    Good (PS 90–100 %) 2

    No. of extra spinal bone metastases foci

    3 0

    1–2 1

    0 2

    No. of metastases in the vertebral body

    3 0

    2 1

    1 2Metastases to the major internal organs

    Unremovable 0

    Removable 1

    No metastases 2

    Primary site of the cancer 

    Lung, osteosarcoma, stomach, bladder,

    esophagus, pancreas

    0

    Liver, gallbladder, unidentified 1

    Others 2

    Kidney, uterus 3

    Rectum 4

    Thyroid, breast, prostate, carcinoid tumour 5

    Palsy

    Complete (Frankel A, B) 0

    Incomplete (Frankel C, D) 1

    None (Frankel E) 2

    Criteria of predicted prognosis: Total Score (TS)

    0–8   ¼   >6 month; TS 9–11   ¼ 6 month; TS

    12–15 ¼ 1 year 

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    circulation to the bone marrow and grow within

    the bone. Thus the tumour cells are able to per-

    form a number of basic activities and to induce

    reproducible angiogenesis, invasion of soft tissue

    and bone turnover.

    Angiogenesis

    Tumours developed in two phases and vascular 

    pre-vascular. The first can exist for months and

    years and is characterized by limited growth and

    little or no metastasis. The vascular phase, on the

    contrary is characterized by rapid growth and

    metastasis microscopic bleeding. To enter thestream vascular tumours should develop vessel

    formation at the site of the primary tumour. In

    the absence of angiogenesis localized tumour 

    masses do not reach a diameter greater than

    2 mm (106 cells). After the formation of the

    vascular access to tumours, the tumour cells

    get into the bloodstream and allow the release

    of growth factors and matrix proteins of the

    tumour. These are produced in the endothelium

    of new capillaries and are responsible for pro-ducing a paracrine invasion and the growth of 

    tumour cells (Fig. 1).

    The importance of angiogenesis in the

    metastatic process is very clear, and corroborated

    by the fact that some cancers have an inverserelationship with vascularity and patient survival.

    This is especially true for prostate cancer 

    Table 2   Tomita score. Tomita [13] proposed in 2001 a three prognostic factor score for SM (Table 3)

    Scoring system

    Prognostic factors

    Point Primarytumor

    VIsceralmets.

    Bonemets.

    Slowgrowth

    [Breast,thyroid, etc]

    [Kidney,uterus etc]

    [Lung,stomach, etc]

    Solitaryor

    isolated

    Moderategrowth

    rapidgrowth

    un-treatable

    treatableMultible

    Prognosticscore

    4

    2

    1

    2

    3

    4

    5

    6

    7

    8

    9

    10

    Treatmentgoal

    Surgicalstrategy

    Long-termlocal control

    Middle-termlocal control

    Short-termPalliation

    Terminalcare

    Supportivecare

    Palliativesurgery

    Marginal orintralesional

    excision

    Wide or Marginalexcision***

    Table 3   Harrington Spinal Metastases categories in rela-tion with neurological status the SM could be classified in

    five categories following Harrintong [14] classification

    score. Harrington classification based on structural defect

    and neurological deficit

    Class

    Neulogical

    status Structural changes

    I Not

    significant

    No vertebral collapse

    II Not

    significant

    Vertebral involvement

    without collapse or instability

    (lytic or blastic lesion)

    II Major  

    (sensory or 

    motor)

    No significant bone

    destruction or instability

    IV Not

    significant

    Mechanical pain from

    vertebralcollapse ¼ or – Instability

    V Major Retropulsion of hard

    discovertebral

    elements ¼ or – Kyphotic

    deformity

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    and breast, so these vascular tumours have

    a higher probability of developing distant metas-

    tases than those with a low level of  

    vascularisation.

    Invasion of Soft Tissue

    At the end of the process there is metastatic

    invasion of the stroma and the basement

    membrane. This process of invasion of soft

    tissues has three phases: link, matrix destruction

    and migration. The invasion by cancer cells

    occurs with the binding of extracellular matrixcomponents, secreting enzymes degrading the

    matrix and moving through the tissue. Without

    these processes the cancer cells cannot enter the

    adjacent vessels or nodes, and as a result

    are not able to travel to distant organs such as

    the lungs or bone (Fig. 2).

    Bone Resorption

    The invasion of tumour cells at the site of skel-

    etal metastases is very different from the

    invasion which occurs in the primary tumour.

    To invade bone, the tumour cells must penetrate

    the connective tissue mineralization. The

    destruction of the mineralized portion of the

    bone is a passive process that requires a low

    pH and the destruction of the portion of bonecollagen is an active process that requires

    the action of enzymes-collagenases. Unlike the

    Fig. 1   Tumour angiogenesis and neovasculature. Toenter the stream vascular tumours should develop vessel

    formation at the site of the primary tumour. In the absence

    of angiogenesis localized tumour masses do not reach

    a diameter greater than 2 mm (106 cells)

    Fig. 2   Invasion of soft tissue. This process of invasion of soft tissues has three phases: link, matrix destruction and

    migration

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    destruction that occurs in tumour cells of soft

    tissue is the direct activity of the cells them-

    selves, resorption of bone metastases occurs

    with the activation of osteoclasts. Osteoclasts

    destroy cells as fraction of mineralized bone

    like (Fig. 3).

    Eighty-five percent of metastatic spinal

    lesions are located in the vertebral body, being

    intramedullary. Other locations are epidural,paravertebral and foraminal. In patients with

    spinal metastasis, pathological fracture can

    occur under normal physiological stress. Partial

    or total destruction of the anterior vertebral body

    results in decreased load-bearing capacity of the

    spine. How and when pathological fracture

    occurs is generally determined by the size and

    location of the tumour, the extent of tumour 

    destruction, and the patient’s bone mineral

    attenuation [14]. The threshold for pathologicalfracture can be accurately predicted by

    evaluating the relationship between bone mineral

    attenuation and the cross-sectional area of the

    intact vertebral body [15].

    Mechanism of Spinal CordCompression

    The spinal cord injury secondary to metastatic

    process is estimated at 8.5 per 100,000, some-

    what higher than traumatic spinal cord injury.

    The outcome of it is directly related to the nature

    of the disease. There are several reasons

    responsible for spinal cord injury: direct com-

    pression expansion tumour or retropulsion

    a bone fragment in pathological fractures,kyphotic deformity which collapses the body

    and intradural metastatic lesion without evidence

    of a bone lesion. In all these situations this is due

    to through an alteration of vascularity there

    develops a state of irreversible nervous tissue

    ischaemia. It may be important to take surgical

    action quickly at the first signs of spinal cord

    compression.

    Diagnosis

    Symptoms-general: we need a complete medical

    history by about weight loss, anorexia, fatigue

    and changes in bowel habits and urinals.

    Spine pain is the most common presentation,

    about 85 % of patients. The pain is usually insid-

    ious at first and tends to be progressive. When

    there is pain pathological fracture may have an

    acute presentation. The location may be cervical,thoracic, lumbar or lumbosacral. The cause of the

    pain is from vertebral body cortical expansion

    and invasion of soft tissues. The pain is usually

    worse with standing and walking and does not

    yield to rest, even waking the patient at night. By

    itself is not a mechanical pain, but it affects the

    stability of the spine [16].

    Radicular pain: indicates compression or inva-

    sion of the root growth of the tumour or patho-

    logical fracture. This pain radiated does notrespond to rest and is difficult to respond to

    Fig. 3   Bone resorption. The destruction of the mineral-ized portion of the bone is a passive process that requires

    a low pH and the destruction of the portion of bone

    collagen is an active process that requires the action of 

    enzymes collagenases. Osteoclasts destroy cells

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    treatment. Muscle weakness is present in 70 % of 

    patients with metastases as a first symptom, but

    we know how to differentiate between neurolog-

    ical deficit and weakness secondary to systemic

    disease.

    Physical examination: assess cachexia or skinlesions and spinal deformity caused by muscle

    contraction or by vertebral collapse. Selective

    spinal palpation looking for points of pain. Discard

    the existence of lymphadenopathy. The full neuro-

    logical assessment should include: exploring sen-

    sory, and motor reflexes in all four extremities.

    Sensory level-look at chest and abdomen; assess-

    ment of medullary cone with examining the func-

    tion of sphincters.

    Radiology: We usually we ask projections lat-eral and AP alignment to assess vertebral bone

    and soft tissue integrity. But keep in mind that

    radiology image shows no pathological involve-

    ment until reaching between 30 % and 50 % of 

    trabecular bone loss. Once we see the radiologi-

    cal injury we should study the location of 

    vertebrae, the pedicle appearances (“winking

    owl” in AP), the radiological pattern (lytic,

    blastic or mixed), the existence of deformity

    (kyphosis, subluxation) and the existence of path-ological fracture.

    The radiological evidence of tumour depends

    on the type of tumour and is seen in 94 % of breast

    tumours, 74 % of lung tumours and 40 % of 

    lymphomas and in 85 % of neoplastic spinal

    cord compression. A normal radiograph does

    not exclude metastatic involvement.

    Bone scintigraphy: shows the existence of 

    osteoblastic activity throughout the skeleton

    tracking and representing an important tool inscreening for vertebral neoplasia. In the case of 

    multiple involvement it helps us to choose the

    most suitable site to perform a biopsy. It is

    much more sensitive than radiography for it

    gives earlier diagnosis, but is not

    specific. However scintigraphy together with lab-

    oratory and physical examination can identify up

    to 95 % of metastatic lesions.

    CT: This gives us the best picture of bone

    involvement and the degree of bone destruction.It plays an important role in surgical planning in

    the case. With the help of intrathecal contrast one

    can better delimit the nerve structures in cases

    where it is not possible to perform MRI.

    MRI: The examination of choice to define

    metastatic spinal disease. It is a non-invasive

    technique that gives images in several planesand not just the injury but an anatomical region.

    You can evaluate the bone marrow, meninges and

    paravertebral space. It has high sensitivity to

    reflect changes in the bone marrow, leading us

    to overestimate sometimes the picture. MRI

    allows us to distinguish between infection that

    affects the spinal disc space from the metastatic

    lesion that affects the intervertebral disc.

    Angiography: is indicated for: (1) pre-operative

    embolization of highly vascularised tumours,(2) location of the vascularity of the lesion, and

    (3) identification of the artery of Adamkiewicz or 

    neural vascularisation of the area.

    PET

    Finally, positron emission tomography (PET)

    employs tagged molecules to detect regions of 

    increased uptake. F-fluoride detects regions of increased fluoride uptake and thereby serves as

    a marker of skeletal re-modelling. Fluorodeox-

    yglucose (FDG) aggregates in regions of 

    increased metabolic activity in the skeleton and

    soft tissues and signals regions of neoplastic,

    inflammatory, or infectious activity. Both

    F-PET and FDGPET scans have been shown to

    be useful in staging systemic disease in cancer 

    patients in combination with CT and MRI. All of 

    the nuclear modalities provide better definition of lytic and mixed lesions in comparison to sclerotic

    lesions. This is likely related to the acellular and

    thereby hypometabolic nature of sclerotic

    lesions.

    Biopsy: percutaneous vertebral biopsy can be

    performed and it is indicated to confirm metastatic

    disease in a patient with a known primary tumour,

    to evaluate a suspicious radiographic lesion, or to

    provide tissue for hormonal evaluation.

    Percutaneous biopsy is better performed usinga large biopsy needle in order to obtain

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    a sufficient amount of tissue. The biopsy can be

    performed under image intensifier control but CTguidance is preferable because of the more accu-

    rate spatial resolution (Figs. 4 and 5).

    The accuracy rate for percutaneous bone

    biopsies is reported to be 90 % in diagnosingmetastatic lesions and the complication rate is

    as low as 0.2 % [17].

    Fig. 4   Vertebroplasty of a matestasisc lesion in the lumbar area

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    Fig. 5   Posterior decompression and instrumentation in acute metastasis with epidural metastases mass

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    Treatment of Spinal Metastases andIndications for Surgery

    Spinal metastasis treatment needs a multidis-

    ciplinary approach. Depending on the primarylesion, the degree of osseous destruction and

    neurological compromise, as well as patient

    co-morbidity and expectations, the treatment of 

    metastatic spinal lesions needs to be

    individualized.

    Different possible modalities include, non-

    surgical measures, with pain management and

    use of bisphosphonates to minimize risk of oste-

    oclastic destruction of bone, chemotherapy, radi-

    ation therapy and surgery.

    Steroids

    The use of glucocorticoids [18] in the treat-

    ment of metastasis with neurological thought

    to be due to oedema probably has an effect. Of 

    all these, dexamethasone is most recommended

    for its minimal effect on the retention of salt

    and the relative potency over other corticoste-roids. Two types have been recommended-low

    dosage (4 mg every 6 h) or high (100mgrs

    initial ev, and 24 mgrs oral every 6 h for 

    4 days). There are however serious potential

    complications of therapy with steroids, which

    include psychosis, diabetes, increased suscep-

    tibility to infections and gastro-intestinal

    bleeding.

    Chemotherapy

    Krakoff [19] defines three types of tumoral

    sensitivity to chemotherapy (8):

     Highly sensitive: Childhood cancers (like acute

    lymphocytic leukaemia, Wilms tumour,

    Ewing’s tumour, retinoblastoma, and rhabdo-

    myosarcoma). Hodgkin’s lymphoma, Carci-

    noma of the testis, Choriocarcinoma,

    Burkitt’s tumour or Acute promyelocytic leu-kemia. In many centres chemotherapy is con-

    sidered the primary treatment for patients with

    these tumours even in the presence of epidural

    compression.

     Moderately sensitive: Adenocarcinoma of breast,

    Non-Hodgkin’s lymphoma, Lung cancer,

    Osteosarcoma, Adult myeloid and lympho-

    cytic leukemia, Carcinoma of the prostate,Colorectal carcinoma, Female cancers of the

    ovary, endometrium, and cervix.

     Minimally sensitive: Endocrine gland cancers,

    Malignant melanoma, Hepatocellular carci-

    noma, Renal carcinoma, Pancreatic

    carcinoma.

    Radiation Therapy

    Can be used for treatment of bone pain or neuro-

    logical deficits in the absence of mechanical com-

    promise. In the last years some advances in

    imaging technology and computerized treatment

    planning have allowed the safe delivery of high-

    dose radiation (spinal radiosurgery) and local

    control pass to figures around 70–90 %

    depending the histology of the tumour [20].

    Conventional RadiotherapyStrong recommendation with moderate- quality

    evidence that conventional fractionated RT is an

    appropriated initial therapy option in SM with no

    relative contra-indications (spinal instability,

    prior irradiation, radio-resistant histology and

    high-grade spinal cord compression).

    Radiosurgery

    Strong recommendation with low-quality evi-

    dence that radiosurgery should be consideredover RT for SM in the setting of oligometastatic

    disease and/or radio-resistant histology with no

    relative contra-indication.

    Surgical Management

    Surgical treatment of vertebral metastases is

    a real challenge for a spine surgeon. There are

    many strategies currently available for thisdisease, starting with observation to aggressive

    en bloc spondylectomy. Furthermore, it is not

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    enough to assess the patient only from the

    surgical point of view, it is mandatory to assess

    the stage of his cancer, needing a multidis-

    ciplinary team. Patients with spinal metastases

    are often compromised and at higher risk for 

    surgical and medical complications after aggres-sive treatment.

    A prospective randomized clinical trial

    conducted by Patchell et al. [21] provides fairly

    convincing support for the role of surgery in the

    treatment of patients with spinal cord compression

    secondary to metastatic solid tumours. The multi-

    institutional trial included patients with a tissue-

    proven diagnosis of cancer with a single metastatic

    spinal tumour causing displacement of the spinal

    cord and at least a single neurological sign or symptom, which included pain.

    The protocol randomized patients into two arms

    in a non-blinded fashion. All patients received

    high-dose dexamethasone at the time of randomi-

    zation. The radiation group underwent 30 Gy in

    10 fractions. Patients in the surgical group

    underwent an operation, with the goal of achieving

    circumferential decompression, and went on to

    receive the 30-Gy radiation treatment within

    14 days of the operation. The investigators termi-nated the trial after interim data analysis demon-

    strated clear superiority of the surgical group in the

    primary end-point of the study, which was the

    ability to walk after treatment. Patients with spinal

    metastases may undergo a wide range of surgical

    interventions, ranging from limited decompression

    to radical tumour excision.

    Indications and Contra-Indications

    Surgery is indicated in patients with rapidly

    progressing or far-advanced paraplegia, histologi-

    cal diagnosis in an unknown primary spinal insta-

    bility and/or pathological fracture–dislocation,

    failure of radiotherapy/known radio-resistant

    lesion Relative contra-indications to surgery are

    longstanding complete paralysis (less 24 h) highly

    radiosensitive tumour (lymphoma, myeloma)

    multiple levels of involvement, poor life expec-tancy (less 3 month) and extreme medical

    co-morbidity.

    Operative Technique

    All patients with mechanical instability require

    a spinal stabilization procedure because radiation

    therapy and chemotherapy do not restore spinalstability. Depending on the degree of instability

    and tumour infiltration, instrumented stabiliza-

    tion or vertebroplasty can be performed. Finally

    some hard selection cases could be treated with

    en bloc resection.

    Vertebroplasty and Kyphoplasty

    Kyphoplasty or vertebroplasty provides fairlydurable and consistent pain relief for patients

    with tumours that infiltrate only the vertebral

    body, without significant involvement of the pos-

    terior elements and an epidural tumour burden. If 

    the tumour infiltrates the posterior elements or 

    significantly extends into the spinal canal, an

    instrumented stabilization is generally required

    to restore stability and provide adequate pain

    relief (Fig. 4).

    A review of 97 cement augmentationprocedures performed in 56 patients with various

    metastatic spinal tumours revealed that

    improvement or complete pain relief was

    achieved in 84 % of the procedures [22]. Further-

    more, these procedures may be effectively

    conducted in conjunction with spinal stereo-

    tactic radiosurgery to treat or prevent patholo-

    gical compression fractures [23]. The most

    common complications of cement injection are

    extravasation into the venous plexus or theepidural space and embolization via the vascular 

    system.

    Decompression and Instrumentation

    After to reviewing the evidence-based

    medicine literature we strong recommend

    management of patients with high-

    grade spinal cord compression secondary tosolid SM by decompressive surgery and

    instrumentation.

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    Depending on the location of the tumour and

    the goal of the operation, an anterior, posterior,

    or lateral approach, or a combination may be

    used. The posterior approach to the spine allows

    direct access to the spinal cord, obviating the

    extensive bone resection generally requiredwith anterior approaches. Furthermore, T3

    through T12 nerve roots may generally be

    sacrificed without significant morbidity, facilitat-

    ing transpedicular access to the ventral elements

    of the vertebral column. Most spine surgeons

    have greater familiarity with the posterior 

    approach to the spine, and thus the posterior 

    approach represents the most commonly used

    route for spinal decompression and stabilization

    (Fig. 5).

    The surgical approach could be influenced by

    location.

    In the thoracolumbar area we reviewed in

    detail 32 of 161 articles with different degreesof evidence.

    • The choice of approach was selected largely

    based on tumour topography in relation to the

    anatomical parts of the vertebra involved.

    • The outcomes for either of these approaches

    were similar.

    • Posterior approach had a higher rate of wound

    problems.

    Fig. 6   (continued)

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    • More wound healing problems with previous

    radiation.

    Our personal advice is:T2 through T5: strong recommendation for 

    a posterolateral approach

    T6 through L5: strong recommendation for use of 

    any of the three procedures (Ant, Post, Com-

    bined) depending on the clinical presentation,surgeon and patient preference. In lumbar 

    level sacrifice of nerve roots carries greater 

    Fig. 6   En bloc resection in an isolated breast metastases

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    morbidity, and cardiopulmonary status may

    precluded anterior approach.

    Cervical location:

    Occipital to C2 by posterior approach

    C3-C6 by anterior approach

    And cervicothoracic area by posterior approach.

    En Bloc Resection

    The main question is: Which is the role of en bloc

    surgery for metastatic tumours of the spine?

    Theoretical evidenc for en bloc resection but

    there is a paucity of published experience in SM

    treatment and the majority of these articles are

    about renal cell carcinoma (Fig.   6). This isa comparative table between debulking and en

    bloc resection of solitary SM We conclude and

    we follow this procedure in patients suffering

    from single spinal metastasis deriving from

    the primary tumour, with a long life expectancy

    and already treated, but we also need to include:

    tumour size, location, WWB surgical score

    classification in order to know if it’s possible

    to do it.

    Complications

    The rate of complications from surgical proce-

    dures on tumour affected vertebral bodies is

    high. The majority of the patients are old-aged

    and their general condition is reduced.

    Hence particularly the mobility after surgery

    of these patients is limited. Pulmonarycomplications, thrombosis and decubitus are

    frequent consequences. Steroid therapy and/or 

    radiotherapy often is/are the reason(s)

    for wound healing disorders. Patients with

    very vascular tumour metastases (renal

    cell carcinoma, plasmocytoma) in many cases

    suffer from intra-operative complications and

    post-operative hematomas. Researching the

    literature, the overall rate of complications

    from surgical procedures on a tumour af- fectedspine with metastases is high.

    Summary

    The spine is the most common site of skeletal

    metastases. The evolution of surgical methods,

    medical treatment, and radiation therapy has ledto improved survival, functional status, and

    quality of life for patients with cancer. The role

    of surgery in the treatment of patients with spinal

    metastases has evolved over time.

    The treatment goals of spinal metastases

    include the preservation and restoration of 

    neurological function and spinal stability. Mod-

    ern imaging modalities provide accurate methods

    of tumour diagnosis. A variety of approaches and

    stabilization techniques are available and shouldbe tailored to the location of the tumour and

    systemic co-morbidities.

    As part of multidisciplinary treatment that

    includes radiation therapy and chemotherapy,

    surgery provides an effective method of 

    restoration and preservation of neurological

    function and spinal stability for patients with

    metastatic spinal tumours.

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