Spine Oncology, An Issue of Orthopedic Clinics.pdf

Spine Oncology

Preface

Rakesh Donthineni, MD, MBA Onder Ofluoglu, MD

Guest Editors

The management of spine tumors has progressed

dramatically over the last few decades. The

emerging diagnostic technologies, novel adjuvant

agents, and improved surgical techniques have

helped the survival and quality of life for these

patients. A wide array of reconstructive options

of the vertebral body, along with the preoperative

planning assisted by the modern imaging modali-

ties, have boosted the confidence of surgeons to

tackle more challenging cases. Daedalean efforts

are needed to not only contain the tumor but

also to eradicate it. As the experts in spine oncol-

ogy from around the world are gaining and sharing

their knowledge of the management of these diffi-

cult diseases, it is helping formulate better studies

to validate our present methods, as well as

develop new ones.

A collection of esteemed specialists from

around the world have contributed their thoughts

in this issue of Orthopedic Clinics of North America

focused on spine oncology. We are indebted to

them for not only bringing forward the latest ideas

and expertise, but in the process allowing the vast

others to extract the relevant information pertain-

ing to their patients’ diseases.

We are grateful to Deb Dellapena and Elsevier

for this creative opportunity; and our families,

friends, and colleagues for their patience, under-

standing, and support.

Rakesh Donthineni, MD, MBA

Spine and Orthopaedic Oncology

5700 Telegraph Avenue

Suite 100

Oakland, CA 94609, USA

Department of Orthopaedics

University of California Davis

Suite 3800, Y Street

Sacramento, CA 95817, USA

Onder Ofluoglu, MD

Department of Orthopedics

Lutfi K | rdar Research Hospital

x emsi Denizer Cd. E-5

Karayolu Cevizli Mevkii 34890

Kartal/Istanbul, Turkey

E-mail addresses:

rdmd.inc@gmail.com (R. Donthineni)

oofluoglu@gmail.com (O. Ofluoglu)

Orthop Clin N Am 40 (2009) xi

doi:10.1016/j.ocl.2008.10.003

Diagnosis and Staging

of SpineTumors

Rakesh Donthineni, MD, MBA a , b , *

KEYWORDS

Spine Tumor Diagnosis Benign

Malignant Metastasis

As the expected incidence of cancers in the United

States approaches 1.5 million cases for 2008, and

with more than 0.5 million deaths, it ranks second

only to cardiovascular disease insignificance.Nearly

three quarters of all cancers are diagnosed in per-

sons 55 years and older. The incidence per year of

breast and prostate cancers are approximately

180,000 each, and slightly more for lung cancer.

With the improvement in diagnosis and treatment

methods, there is an increasing trend in long-term

survival by about 30%. 1 As patients with cancers

have longer survival, there is an expected increase

in the prevalence of metastatic disease.

With a higher incidence and prevalence of can-

cers of other organs of the body, there are more

symptomatic or asymptomatic cases of metastatic

disease to the spine than primary tumors. 2 Au-

topsy studies demonstrated between 30% and

90% of spinal metastases in patients with a history

of other malignancy. The common primaries were

lung, breast, lymphoma, and myeloma. Nearly

17% of patients with other primaries may present

with spinal cord compression as a result of metas-

tases. 3–5 Metastases to the spine have a predilec-

tion toward the thoracic spine, followed by the

lumbar and cervical. 6

More than 2000 bone and joint cancers and about

10,000 soft tissue cancers are diagnosed per year. 1

The incidence of benign tumors of the spine is a little

more than 1% of all primary skeletal tumors, and

nearly 5% for malignant tumors. 7 Within the benign

tumors, giant cell tumors, osteoid osteomas, osteo-

blastomas, and hemangiomas are more likely. Al-

though the incidence of hemangioma of the spine

is about 10% in the general population, only a small

percentage develop symptoms. 8,9 Apart from the

hematopoietic tumors, including myeloma and lym-

phoma, theprimarymalignant tumors of the spine in-

clude chordoma, chondrosarcoma, osteosarcoma,

and others.

PRESENTATION

Patients with spinal tumors most often present

with axial pain, and some with radicular pain

(if the tumor is extends to and compresses the

nerves). A lesser percentage present with cauda

equina syndrome and most of these are a result

of metastatic disease and rapidly growing tumors.

The cervical lesions tend to progress slowly in

terms of neurologic symptoms, whereas the thor-

acolumbar lesions are more aggressive and are

more clinically affected. About 60% will present

with central or nerve root symptoms, and more

than a third will present with a motor deficit.

Sphincter function alterations in isolation are less

frequent (less than 3%). 10

Patients with cord compression not only have

symptoms of sensory or motor disturbances, but

most of them (>90%) have pain. There is often

a delay from the time of the presentation of symp-

toms to the alterations in signs, and therefore, a de-

lay in evaluation by the primary care doctor to the

point of full diagnosis and management by a spe-

cialist. Plain radiographs may help in diagnosis in

a fifth of the patients, whereas an MRI is much

more useful in identifying the level of compres-

sion. 11 As part of the patient evaluation and fol-

low-up, the extent of the neurologic dysfunction

should be carefully mapped. 12

Financial disclosure: no funding of any sort was obtained to conduct this review.

a Spine and Orthopaedic Oncology, 5700 Telegraph Avenue, Suite 100, Oakland, CA 94609, USA

b Department of Orthopaedics, University of California Davis, Suite 3800, Y Street, Sacramento, CA 95817, USA

* Spine and Orthopaedic Oncology, 5700 Telegraph Avenue, Suite 100, Oakland, CA 94609.

E-mail address: rdmd.inc@gmail.com

Orthop Clin N Am 40 (2009) 1–7

doi:10.1016/j.ocl.2008.10.001

Donthineni

The cause of the axial pain in patients with spinal

tumors is because of the destructive effect of the

tumor, the cortical breakdown, and also from

extension into the canal with compression of the

cord. Weakening of the vertebrae will likely lead

to fractures, micro or macro, causing pain. The

posterior longitudinal ligament is the weakest

barrier for tumor growth, and the tumor often

extends at points of perforating vessels. Spread

to adjacent vertebrae is likely at the edge of the

level involved beneath the longitudinal ligament,

and via paravertebral muscles. 13,14

The extension of metastatic tumors to the axial

spine is mainly through the vascular mechanism, ei-

ther by seeding via the arterial system or a closer

spread via the valveless extradural venous system

(Batson’s venous plexus). A more direct extension is

seen in the pulmonary apical tumors. Although the

mechanical spread of the tumors seems logical, the

tendency of the tumors to settle in some environments

more than others, as related to the molecular and

surface protein behavior, should not be ignored. 15–18

In patients with a history of a previous adenocar-

cinoma or other malignancies, a new focus of tu-

mor in the skeletal system often correlates with

the historical primary, but needs to be corrobo-

rated. Without such a history, an unidentified focus

should prompt the search for the primary. A thor-

ough history, examination, the basic laboratory

studies, plain radiographs, and other appropriate

imaging of the affected site, whole body techne-

tium-99m-phospate bone scan, and CT scan of

the chest, abdomen, and pelvis often identifies

most of the primary sites. Biopsy of the lesion

adds significant information, but if done alone

has a lesser yield than the combine effort. There

may still be a small percentage where the primary

may not be identifiable. 4,19–22

Once identified, whether a primary or secondary

tumor, the next step should be the appropriate

planning for management. Although imaging stud-

ies, such as MRI and CT, have greatly assisted in

diagnosing based on radiographs, only a few

tumors can be diagnosed without a histologic

evaluation. Osteoid osteoma is one such tumor

that can be diagnosed on the plain radiographs

and CT, and one can proceed with the treatment,

whether it be a surgical excision or a percutaneous

ablation (radiofrequency ablation). With regard to

metastatic disease, the indications for surgical

intervention are intractable pain, worsening neuro-

logic deficit, a pathologic fracture, and instability.

do not contribute much to the diagnosis in primary

tumors of the musculoskeletal system. Elevated

erythrocyte sedimentation rate can be found in

round cell tumors, benign or malignant, and also

in infections. Serum and urinary protein electro-

phoresis are helpful in identifying myeloma. Low

hematocrit may suggest a marrow infiltrative pro-

cess, although it could also signify an advanced

stage malignancy.

As part of the workup, imaging studies follow

suit. Plain radiographs should be included, as

they are easily accessible and allow approximate

localization of the disease process (if visible on

the radiographs), but also assist in evaluating the

curvature of the spine and any changes in its struc-

tural appearance secondary to changes in the

biomechanics.

Lytic tumors are not easily identified on plain ra-

diographs until close to 50% of bone destruction

occurs. Increasing destruction (cross-sectional

area) and a poor bone mineral density in combina-

tion contribute to a higher likelihood for compres-

sive fractures. In the thoracic vertebrae, although

a larger defect may portend to a compression frac-

ture, the intact costovertebral joints play a signifi-

cant support to the overall structure, and as

such, any involvement of these joints rapidly leads

to a vertebral collapse. 23–26

Once the involved level is identified, CT and MRI

are the studies of choice to give much more data

on the distribution of the tumor within the verte-

brae, its extension, and effects on the local anat-

omy. MRI with intravenous contrast (Gadolinium)

will assist in identifying the areas of most activity,

and may direct the placement of the biopsy needle

to achieve a high yield. Whole-body technetium-

99m bone scan will help identify other sites of in-

volvement, and hence help stage the disease, or

even identify another location that may be an eas-

ier site for obtaining a piece of tissue for diagnostic

purposes ( Fig. 1 ).

Angiography may be used, but more as a treat-

ment in benign highly vascular tumors (eg, ABC,

GCT) or in preparation for the surgical treatment

of a vascular tumor (eg, renal and thyroid metasta-

ses, and multiple myeloma) and thereby decreas-

ing the blood loss intraoperatively. 27–30

BIOPSY

A biopsy is mandatory if the isolated spinal lesion

is unknown, even in the face of a distant history

of a primary malignancy, as occasionally a new

primary may be encountered. If the patient has

a known history of metastatic disease with multiple

lesions, the new troublesome spinal lesion may be

LABORATORYAND IMAGING STUDIES

Apart from the basic workup of a patient with the

spine tumor, most of the blood and serum studies

Diagnosis and Staging of Spine Tumors

Fig. 1. Whole body bone scan demonstrating the ex-

tensive metastatic disease.

tissue and is helpful in sclerotic lesions, but the

associated rates of complications increase. 32

Albeit the varying results, image-guided transpe-

dicular biopsy of the vertebral lesion is still the fa-

vored technique, the choice of imaging either

fluoroscopy or CT ( Figs. 2 and 3 ). 33 Percutaneous

CT guided (via the pedicle or otherwise) is often

the standard approach by the interventional radiol-

ogists, as they have access to the appropriate im-

aging machines, and the overall accuracy has

been reported to be about 89%, with lytic lesions

having a better yield (93%) versus the sclerotic/

blastic lesions (76%). The sclerotic lesion accuracy

is less than that for lytic or mixed lytic-sclerotic le-

sions or compression fractures, and also the false

negative biopsies are higher in the sclerotic lesions.

The accuracy is also lower if the lesion is visible

on the MRI but not clear on CT imaging at the

time of the biopsy. 34 MRI-guided biopsies are avail-

able and can helpful in locating the biopsy needle in

the viable part of the tumor to give a higher diagnos-

tic yield. 35

Open incisional or excisional biopsies must be

properly planned and approached with an incision

small enough to allow a future resection, in cases

of recurrence or when dealing with a primary ma-

lignancy. Contamination of neighboring structures

should be limited as much as possible, and the

path of approach should be away from any vital

neurovascular structures, as any contamination

would require resection of these structures to

prevent or decrease recurrences. Meticulous

hemostasis is a must, as the seeping blood may

treated without the need for further histologic

proof before dealing with the offending lesion.

Before planning the biopsy, the imaging studies

need to be evaluated to ascertain the exact loca-

tion of the tumor within the spinal column, and

also to identify the most viable area on the MRI

(with intravenous contrast), henceforth yielding

the best tissue for diagnosis. The process of

obtaining the tissue may be with a fine needle,

core, incisional, or excisional. Needle and core

biopsies are conducted percutaneously, with the

difference being in the diameter of the bore.

Incisional biopsy is conducted when an open ap-

proach to the tumor is conducted and a small

piece of the tumor is obtained for analysis, leaving

the rest in situ. In excisional biopsy, the whole

tumor is removed with an intralesional, marginal,

or wide margin.

Percutaneous biopsies, with fine needle aspira-

tion or core biopsy, for musculoskeletal lesions

have a favorable outcome in about 75% of the

cases. 31 Fine needle aspiration may be adequate

in metastatic tumors or in recurrences, whereas

in cases of primary tumors, adequacy of tissue

helps in the accuracy of diagnosis. Also, sufficient

tissue is needed for not only for the standard stains

in histology, but also possibly for immunostains

and other studies, including cytogenetics. Increas-

ing the diameter of the needle will obtain more

Fig. 2. Fluoroscopy-guided transpedicular approach

for a vertebral body biopsy.

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