Spinal cord compression due to metastatic disease: diagnosis with MR imaging versus myelography

State-of-the-Art Imaging Techniques in Metastatic Spinal Cord Compression

Metastatic Spinal Cord Compression (MSCC) is a debilitating complication in oncology patients. This narrative review discusses the strengths and limitations of various imaging modalities in diagnosing MSCC, the role of imaging in stereotactic body radiotherapy (SBRT) for MSCC treatment, and recent advances in deep learning (DL) tools for MSCC diagnosis. PubMed and Google Scholar databases were searched using targeted keywords. Studies were reviewed in consensus among the co-authors for their suitability before inclusion. MRI is the gold standard of imaging to diagnose MSCC with reported sensitivity and specificity of 93% and 97% respectively. CT Myelogram appears to have comparable sensitivity and specificity to contrast-enhanced MRI. Conventional CT has a lower diagnostic accuracy than MRI in MSCC diagnosis, but is helpful in emergent situations with limited access to MRI. Metal artifact reduction techniques for MRI and CT are continually being researched for patients with spinal implants. Imaging is crucial for SBRT treatment planning and three-dimensional positional verification of the treatment isocentre prior to SBRT delivery. Structural and functional MRI may be helpful in post-treatment surveillance. DL tools may improve detection of vertebral metastasis and reduce time to MSCC diagnosis. This enables earlier institution of definitive therapy for better outcomes.

Isolated metastatic dorsal spinal cord compression revealing prostatic adenocarcinoma

Prostate cancer is the second common etiology of cord compression after lung cancer. Its slow natural history justifies an aggressive treatment. The fact that the metastatic lesion precedes the primary tumor remains rare.

We report the case of a 86 year-old man who was admitted for heaviness of both lower limbs responsible for gait disorder. He had flaccid paraplegia. Spinal MRI showed an epidural lesion. Histology after surgery was compatible for a metastasis of prostatic adenocarcinoma.

Spinal cord compression due to prostate cancer is correlated with poor prognosis. The fact that the metastatic lesion precedes the primary tumor remains rare.

Assessment and Management of Patients With Metastatic Spinal Cord Compression: A Multidisciplinary Review

Purpose

Metastatic spinal cord compression (MSCC) can be a catastrophic manifestation of advanced cancer that causes immobilizing pain and significant neurologic impairment. Oncologists can protect their patients by having a high index of suspicion for MSCC when patients present with new or worsening back pain before motor, sensory, bowel, or bladder deficits develop. We provide an updated, evidence-based narrative review of the presentation, diagnosis, and treatment of MSCC.

Methods

This narrative review was conducted by searching MEDLINE and Cochrane Database of Systematic Reviews for relevant literature on the presentation, diagnosis, and treatment of patients with MSCC. The article addresses the key elements of MSCC management germane to the medical oncologist, with special attention given to pain and symptom management, decision making with regard to surgery and radiation therapy, the importance of rehabilitative care, and the value of a multidisciplinary approach.

Results

Magnetic resonance imaging of the entire spine is recommended for the diagnosis of MSCC. Treatment includes glucocorticoid therapy, pain management, radiation therapy with or without surgery, and specialized rehabilitation. When formulating a treatment plan, clinicians should consider the patient’s care goals and psychosocial needs.

Conclusion

Prompt diagnosis and treatment of MSCC can reduce pain and prevent irreversible functional loss. Regular collaboration among multidisciplinary providers may streamline care and enhance achievement of treatment goals.

Low back pain, radiculopathy

Low back pain is a pervasive problem in the adult population. Most patients with low back pain will not require imaging as spontaneous recovery within 12 weeks is the rule. However, a small percentage of patients with low back pain will have serious underlying pathology requiring more intensive investigation. This chapter delineates the signs and symptoms related to potential serious underlying causes and discusses appropriate imaging modalities that should be utilized in patients with low back pain.

Low-Field MR Imaging (0.1 T) in Patients with Clinically Suspected Acute Spinal Block

The diagnostic usefulness of a 0.1 T MR unit in patients with clinical suspicion of acute spinal block was studied in 59 patients who were referred to acute MR investigation. The records were reviewed retrospectively 1 month after the MR for assessing the clinical impact of the examination. Ninety-eight per cent had a true-positive examination confirmed by surgery (21%) or observation (77%). In 60% of the patients the MR imaging had a therapeutic consequence. In only one patient did the level of visualised pathology at the MR examination not correlate with the clinical findings; the patient subsequently refused surgical treatment. We conclude that a low-field MR unit is excellent for acute examination of patients clinically suspected of acute spinal block.

The 100 most cited articles in metastatic spine disease

OBJECTIVE

Despite the growing neurosurgical literature, a subset of pioneering studies have significantly impacted the field of metastatic spine disease. The purpose of this study was to identify and analyze the 100 most frequently cited articles in the field.

METHODS

A keyword search using the Thomson Reuters Web of Science was conducted to identify articles relevant to the field of metastatic spine disease. The results were filtered based on title and abstract analysis to identify the 100 most cited articles. Statistical analysis was used to characterize journal frequency, past and current citations, citation distribution over time, and author frequency.

RESULTS

The total number of citations for the final 100 articles ranged from 74 to 1169. Articles selected for the final list were published between 1940 and 2009. The years in which the greatest numbers of top-100 studies were published were 1990 and 2005, and the greatest number of citations occurred in 2012. The majority of articles were published in the journals Spine (15), Cancer (11), and the Journal of Neurosurgery (9). Forty-four individuals were listed as authors on 2 articles, 9 were listed as authors on 3 articles, and 2 were listed as authors on 4 articles in the top 100 list. The most cited article was the work by Batson (1169 citations) that was published in 1940 and described the role of the vertebral veins in the spread of metastases. The second most cited article was Patchell's 2005 study (594 citations) discussing decompressive resection of spinal cord metastases. The third most cited article was the 1978 study by Gilbert that evaluated treatment of epidural spinal cord compression due to metastatic tumor (560 citations).

CONCLUSIONS

The field of metastatic spine disease has witnessed numerous milestones and so it is increasingly important to recognize studies that have influenced the field. In this bibliographic study the authors identified and analyzed the most influential articles in the field of metastatic spine disease.

MRI of spinal bone marrow: part I, techniques and normal age-related appearances

OBJECTIVE

This article reviews MRI protocols, including routine and nonroutine pulse sequences as well as the normal MRI appearance of spinal marrow and expected age-related changes.

CONCLUSION

Routine MRI of the spine provides useful evaluation of the spinal bone marrow, but nonroutine MRI pulse sequences are increasingly being used to evaluate bone marrow pathology. An understanding of MRI pulse sequences and the normal and age-related appearances of bone marrow is important for the practicing radiologist.

Imaging of spinal metastatic disease

Metastases to the spine can involve the bone, epidural space, leptomeninges, and spinal cord. The spine is the third most common site for metastatic disease, following the lung and the liver. Approximately 60-70% of patients with systemic cancer will have spinal metastasis. Materials/Methods. This is a review of the imaging techniques and typical imaging appearances of spinal metastatic disease. Conclusions. Awareness of the different manifestations of spinal metastatic disease is essential as the spine is the most common site of osseous metastatic disease. Imaging modalities have complimentary roles in the evaluation of spinal metastatic disease. CT best delineates osseous integrity, while MRI is better at assessing soft tissue involvement. Physiologic properties, particularly in treated disease, can be evaluated with other imaging modalities such as FDG PET and advanced MRI sequences. Imaging plays a fundamental role in not only diagnosis but also treatment planning of spinal metastatic disease.

Low yield of ED magnetic resonance imaging for suspected epidural abscess

PURPOSE

The aim of this study was to estimate the yield of emergency department (ED) magnetic resonance imaging (MRI) in detecting spinal epidural abscess (SEA) and to identify clinical factors predicting positive MRI results.

BASIC PROCEDURE

We examined a cohort of patients who underwent MRI to rule out SEA, followed by a nested case-control comparison of those with positive results and a sample with negative results. A positive result was defined as osteomyelitis, discitis, or SEA. Predictor variables included temperature, presenting complaint, drug abuse status, history of SEA or back surgery, midline back tenderness, neurologic deficit, MRI level, mean white blood cell count, erythrocyte sedimentation rate, and C-reactive protein level.

MAIN FINDINGS

Fourteen of the 120 available MRIs were excluded; 7 (6.6%) of the remaining 106 were positive. Temperature was 1.1°C higher in cases than controls (95% CI, 0.6-1.7).

CONCLUSION

Emergency department MRI for suspected SEA has a low yield. Clinical guidelines are needed to improve efficiency.

Back pain in the elderly

Back pain in the elderly is a complex chief complaint, because numerous life-threatening or disabling conditions may present with signs and symptoms similar to those of more benign disease processes. An understanding of the limitations of physical examination and history distinguishing dangerous from benign causes is essential to avoid misdiagnosis and patient morbidity or mortality. This article describes the presentation and evaluation of dangerous causes of back pain, including vascular catastrophes, spinal cord compression syndromes, and infectious diseases. Less emergent musculoskeletal injuries are discussed briefly.

Update in palliative management of hormone refractory cancer of prostate

Hormone refractory prostate cancer (HRPC) is an incurable disease and as in the pressure sensitive adhesive era the median survival of patients is increasing, these men increasingly develop symptomatic problems as a result of advanced local and or metastatic disease during their progression to death. Recently, it has been shown that it is possible to improve survival in this group of patients with use of chemotherapy which reinforces the need of better options in palliative care. We discus the various clinical problems (Part I) and treatment options of palliative care (Part II) and try to formulate an action plan in this review.

Back pain emergencies

Most adults in the United States will experience an episode of back pain at some point during their lifetime. Most will present to their primary care physician for evaluation and treatment. Many patients have non-life-threatening etiologies and recover within 4 to 6 weeks. A small percentage, however, have back pain due to a potentially life-threatening emergency. AD,rupturing AAA, SEM, cauda equina syndrome, vertebral osteomyelitis,and SEA are just some of the medical emergencies that can present with back pain. Clinical suspicion for these diagnoses begins with a thorough history and physical examination. It is imperative that the office-based physician search for and accurately identify any red flag within the history or physical examination. Appropriate laboratory studies and diagnostic imaging are obtained based on the suspected etiology.

Epidural spinal cord compression

Spinal cord compression from epidural metastases (epidural spinal cord compression, ESCC) is the most common neurological complication of cancer after brain metastases. Extradural compression represents 97% of spinal cord metastatic lesions. ESCC usually occurs in patients with disseminated disease. The most common tumours associated with ESCC are lung and breast cancers, followed by lymphoma, myeloma, prostate cancer and sarcoma. ESCC represents a medical emergency because delayed treatment can be responsible for irreversible deficits, such as paralysis and loss of sphincter control. Patients with ESCC require a multidisciplinary diagnostic and therapeutic approach. Clinical suspect is radiologically detected for confirmation. The median expected survival time from diagnosis usually ranges from 3 to 6 months. The nature of the primary tumour and the degree of the neurological deficit are the most important factors affecting survival. The lack of prospective randomized trials makes the optimal treatment of ESCC controversial and the decision is to be tailored to the individual. Treatment options include: bed rest, administration of corticosteroids, surgery followed by radiation therapy, radiotherapy alone and, to a limited extent, chemotherapy and hormonal therapy.

Magnetic resonance imaging of the axial skeleton enables objective measurement of tumor response on prostate cancer bone metastases

BACKGROUND

There is currently no technique to image quantitatively bone metastases. Here, we assessed the value of MRI of the axial skeleton (AS-MRI) as a single step technique to quantify bone metastases and measure tumor response.

METHODS

AS-MRI was performed in 38 patients before receiving chemotherapy for metastatic HRPCa, in addition to PSA, computed tomography of the thorax, abdomen, and pelvis [CT-TAP]; and Tc-99m bone scintigraphy. A second AS-MRI was performed in 20 patients who completed 6 months of chemotherapy. Evaluation of tumor response was performed using RECIST.

RESULTS

Only 11 patients (29%) had RECIST measurable metastases in soft-tissues or lymph nodes on baseline CT-TAP. AS-MRI identified a diffuse infiltration of the bone marrow in 8 patients and focal measurable metastatic lesions in 25 patients (65%), therefore, doubling the proportion of patients with measurable lesions. Transposing RECIST on AS-MRI in 20 patients who completed 6 months of treatment, allows the accurate estimation of complete response (n = 2), partial response (n = 2), stable disease (n = 5), or tumor progression (n = 11), as it is done using CT-TAP in soft tissue solid metastases.

CONCLUSIONS

MRI of axial skeleton enables precise measurement and follow-up of bone metastases as it is for other soft-tissue metastasis.

Systematic Review of the Diagnosis and Management of Malignant Extradural Spinal Cord Compression: The Cancer Care Ontario Practice Guidelines Initiative‘s Neuro-Oncology Disease Site Group

Purpose

This systematic review describes the diagnosis and management of adult patients with a suspected or confirmed diagnosis of extradural malignant spinal cord compression (MSCC).

Methods

MEDLINE, CANCERLIT, and the Cochrane Library databases were searched to January 2004 using the following terms: spinal cord compression, nerve compression syndromes, spinal cord neoplasms, clinical trial, meta-analysis, and systematic review.

Results

Symptoms for MSCC include sensory changes, autonomic dysfunction, and back pain; however, back pain was not predictive of MSCC. The sensitivity and specificity for magnetic resonance imaging (MRI) range from 0.44 to 0.93 and 0.90 to 0.98, respectively, in the diagnosis of MSCC. The sensitivity and specificity for myelography range from 0.71 to 0.97 and 0.88 to 1.00, respectively. A randomized study detected higher ambulation rates in patients with MSCC who received high-dose dexamethasone before radiotherapy (RT) compared with patients who did not receive corticosteroids before RT (81% v 63% at 3 months, respectively; P = .046). There is no direct evidence that supports or refutes the type of surgery patients should have for the treatment of MSCC, whether surgical salvage should be attempted if patient is progressing on or shortly after RT, and whether patients with spinal instability should be treated with surgery.

Conclusion

Patients with symptoms of MSCC should be managed to minimize treatment delay. MRI is the preferred imaging technique. Treatment for patients with MSCC should consider pretreatment ambulatory status, comorbidities, technical surgical factors, the presence of bony compression and spinal instability, potential surgical complications, potential RT reactions, and patient preferences.

Epidural spinal cord compression

Epidural spinal cord compression is a neurologic emergency requiring immediate attention. The therapy instituted depends on several factors, including the patient's condition at the time of presentation, the nature of the underlying malignancy, the extent of systemic disease burden, and patient prognosis. The most essential aspect of treatment is the establishment of the diagnosis. If one suspects malignant cord compression an emergency, magnetic resonance imaging of the entire spinal axis is indicated. If magnetic resonance imaging is unavailable, post-myelographic computed tomography is an alternative. However, treatment should not be delayed until imaging is performed, particularly if neurologic deficits are present. Pain should be adequately addressed and opioids administered if necessary. Steroids should be given. If significant neurologic deficits are present, a high-dose corticosteroid bolus, followed by standing doses, should be given. However, if pain is the predominant symptom, steroids can be withheld pending immediate imaging or lower doses can be given without a bolus. Neurosurgical consultation should be obtained, and surgery should be considered if the patient's condition permits. This is particularly true if spinal instability or significant kyphosis is present or compression is secondary to bony fragments. Other indications include patients with limited systemic disease burden in whom better survival is predicted and possibly those with radioresistant tumors. The type of surgery performed should be tailored to the distribution of disease within the spine and accessibility through anterior body cavities. Radiation therapy, an effective noninvasive treatment that can be delivered quickly and safely, is an appropriate option as well. This is particularly true in radio-responsive tumors, such as myeloma and lymphoma, in which surgery may be avoided entirely. Chemotherapy may play a role as adjuvant therapy in some tumors.

Spinal Cord Compression in Metastatic Prostate Cancer

INTRODUCTION

Spinal cord compression (SCC) in metastatic prostate cancer is not rare occurring in 1 to 12% of patients. We have analysed patients treated for this condition in our institution assessing outcome and prognostic factors.

MATERIAL AND METHODS

Retrospective analysis of the notes of 24 patients hospitalised with SCC due to metastatic prostate cancer from 1987 to 2001.

RESULTS

At presentation 3 patients were ambulant with mild neurological deficit, 12 patients were paraparetic and 9 patients were paraplegic. Diagnosis was established by emergency myelogram, CT-scan or MRI of the spine. 8 patients had received no hormone treatment prior to diagnosis of SCC. 19 patients presented dorsal or lumbar pain requiring opioid treatment on average 60 days before onset of neurological symptoms (range 10-840). All patients underwent steroid treatment; the 8 patients without prior hormone therapy were treated with bilateral orchidectomy, 1 out of these 8 patients had castration without other treatments; 12 patients underwent radiotherapy alone and 9 radiotherapy and laminectomy; 2 patients were in terminal conditions and receive only steroid treatment. Overall 15/24 patients were ambulant after treatment. 8 out of 9 patients treated by laminectomy and radiotherapy were ambulant after treatment versus 7 out of 12 patients treated by radiotherapy alone.17 patients died during follow-up with a median survival of 4 months (2 weeks to 49 months). 7 patients were alive at the last control with a mean follow-up of 10 months (range 4-40).

CONCLUSION

Outlook in patients with spinal cord compression from metastatic prostate cancer is poor. Efforts must be concentrated on prevention of spinal cord compression. Patients with hormone resistant prostate cancer who develop persistent back pain should undergo imaging studies (bone scan, spine CT-scan or MNR) and prophylactic local radiotherapy to the spine if bony metastases are identified.

Conventional radiography, rapid MR imaging, and conventional MR imaging for low back pain: activity-based costs and reimbursement

PURPOSE

To incorporate personnel and equipment use time in an activity-based cost comparison of conventional radiography and conventional and rapid magnetic resonance (MR) imaging for low back pain (LBP).

MATERIALS AND METHODS

At each of four Seattle Lumbar Imaging Project (SLIP) sites, patients were randomized to undergo conventional radiography or rapid MR imaging of the lumbar spine. For sample SLIP patients and for similar non-SLIP patients undergoing conventional lumbar spine MR imaging as usual care in calendar year 2000, measured imaging room use and technologist and radiologist times were multiplied by costs per minute of standard equipment acquisition, personnel compensation, and related expenses. Resulting provider-perspective costs and Seattle area Medicare reimbursements for conventional MR imaging and radiography for calendar year 2001 were used to estimate future "normative" reimbursement for rapid MR imaging.

RESULTS

For 23 conventional radiography, 27 rapid MR imaging, and 38 conventional MR imaging examinations timed in calendar year 2000, all rapid MR imaging times exceeded those of conventional radiography but were less than those of conventional MR imaging. All 0.3- and 0.35-T MR imaging room and technologist times exceeded those for 1.5-T MR imaging. Average costs (in 2001 dollars) were $44 for conventional radiography, 126 US dollars for 1.5-T rapid MR imaging, 128 US dollars for 0.3-0.35-T rapid MR imaging, 267 US dollars for 1.5-T conventional MR imaging, and 264 US dollars for 0.3-0.35-T conventional MR imaging. Conclusions regarding cost differences between conventional radiography and rapid MR imaging were robust to plausible parameter value changes evaluated in sensitivity analyses. Conventional radiography reimbursement was 44 US dollars. Applying the ratio of reimbursement (620 US dollars) to costs (264-267 US dollars) for conventional MR imaging to rapid MR imaging costs predicted reimbursement of 292-300 US dollars for the new modality.

CONCLUSION

Times and costs for rapid MR imaging are roughly three times those for conventional radiography but about half those for conventional MR imaging for LBP. While current conventional radiography costs exceed reimbursement, current conventional MR and projected rapid MR imaging reimbursements exceed costs.

Imaging of adults with low back pain in the primary care setting

The evidence for the diagnostic accuracy of the four main imaging modalities used in low back pain (plain radiographs, CT, MR imaging, radionuclide bone scans) is variable in quality and limits the ultimate conclusions regarding the effectiveness and cost-effectiveness of diagnostic strategies. In addition, the frequent finding of abnormalities in normal adults limits the specificity of all of these tests. Nevertheless, MR imaging is likely in most cases to offer the greatest sensitivity and specificity for systemic diseases, and its performance is superior to that of radiographs and comparable with CT and radionuclide bone scans for most conditions causing neurologic compromise.

Rapid magnetic resonance imaging for diagnosing cancer-related low back pain

OBJECTIVES

This study compared the relative efficiency of lumbar x-ray and rapid magnetic resonance (MR) imaging for diagnosing cancer-related low back pain (LBP) in primary care patients.

DESIGN

We developed a decision model with Markov state transitions to calculate the cost per case detected and cost per quality-adjusted life year (QALY) of rapid MR imaging. Model parameters were estimated from the medical literature. The costs of x-ray and rapid MR were calculated in an activity-based costing study.

SETTING AND PATIENTS

A hypothetical cohort of primary care patients with LBP referred for imaging to exclude cancer as the cause of their pain.

MAIN RESULTS

The rapid MR strategy was more expensive due to higher initial imaging costs and larger numbers of patients requiring conventional MR and biopsy. The overall sensitivity of the rapid MR strategy was higher than that of the x-ray strategy (62% vs 55%). However, because of low pre-imaging prevalence of cancer-related LBP, this generates <1 extra case per 1,000 patients imaged. Therefore, the incremental cost per case detected using rapid MR was high ($213,927). The rapid MR strategy resulted in a small increase in quality-adjusted survival (0.00043 QALYs). The estimated incremental cost per QALY for the rapid MR strategy was $296,176.

CONCLUSIONS

There is currently not enough evidence to support the routine use of rapid MR to detect cancer as a cause of LBP in primary care patients.

A prospective study of factors predicting clinically occult spinal cord compression in patients with metastatic prostate carcinoma

BACKGROUND

The objective of this study was to identify clinical parameters that predict occult subarachnoid space or spinal cord (SAS/SC) compression, as determined by magnetic resonance imaging (MRI), in patients with metastatic prostate carcinoma.

METHODS

A prospective study was performed in which 68 patients with bone metastases from prostate carcinoma and a normal neurologic examination underwent MRI of the entire spine after documentation of clinical, X-ray, and bone scan parameters potentially predictive of occult SAS/SC compression.

RESULTS

Occult SAS/SC compression was diagnosed in 22 patients (32%) using MRI. Nine patients (13%) had compressions at two discontinuous spinal levels. Extensive disease on bone scan, the duration of continuous hormonal therapy prior to study entry, and hemoglobin concentration were found to predict SAS/SC compression by univariate analysis. The extent of disease on bone scan and the duration of continuous hormonal therapy were independent predictors of SAS/SC compression by multivariate analysis (P = 0.02 and P = 0.04, respectively). The risk of occult SAS/SC compression increased from 32% to 44% in patients with a bone scan that showed > 20 metastases as the duration on hormones increased from 0 to 24 months. The risk in patients with fewer metastases increased from 11% to 17% over the same interval. The presence or absence of back pain was not predictive of SAS/SC compression.

CONCLUSIONS

Patients who are at high risk for occult SAS/SC compression can be identified using clinical parameters and readily available diagnostic tests. These high-risk patients should undergo MRI screening with the aim of diagnosing and treating spinal cord compression before the development of neurologic deficits that may be irreversible.

Prostate Cancer Old Problems and New Approaches. Part III. Prevention and Treatment

In Part Three of this review, we begin with an analysis of prevention strategies for prostate cancer followed by a discussion of the clinical use of molecular techniques for the evaluation and treatment of patients with clinically localized prostate cancer. New developments in neutron and photon therapy of prostate cancer are addressed as well as the use of systemic radiotherapy for the treatment of bone metastases. Finally, we conclude with the role of hormonal therapy in the treatment of prostate cancer and the current status of development of chemo therapeutic regimens for the treatment of prostate cancer.

Diagnosis of vertebral metastasis, epidural metastasis, and malignant spinal cord compression: are T(1)-weighted sagittal images sufficient?

The objective of this study was to determine whether T(1)-weighted sagittal images alone are adequate in the diagnosis of vertebral metastasis, epidural metastasis, and malignant spinal cord compression. Ninety-four complete magnetic resonance (MR) studies of the spinal column (a complete study consisting of T(1)-weighted sagittal images, T(2)-weighted sagittal images, and T(1)- and/or T(2)-weighted axial images) and 94 T(1)-weighted sagittal images alone (a subset of the complete studies) from 57 consecutive cancer patients over the last 2 years with clinically suspected cord compression were blindly and independently evaluated by four radiologists. The complete MR studies were used as the standard. Overall, the sensitivity of T(1)-weighted sagittal images alone to vertebral metastasis (87%) was statistically greater than cord compression (70%) (p = 0.05), and statistically greater than epidural metastasis (46%) (p </= 0.02). The specificity for cord compression (97%) was greater than the specificity for epidural metastasis (89%) (p = 0.03), and greater than the specificity for vertebral metastasis (83%) (p </= 0.02). There was a strong trend for better detection of cord compression overall and better detection of vertebral metastasis in the cervical spine by the most experienced radiologist. Complete studies of the spine are necessary in the diagnosis of vertebral metastasis, epidural metastasis, and cord compression, particularly with less experienced radiologists.

Autocorrection in MR imaging: adaptive motion correction without navigator echoes

A technique for automatic retrospective correction of motion artifacts on magnetic resonance (MR) images was developed that uses only the raw (complex) data from the MR imager and requires no knowledge of patient motion during the acquisition. The algorithm was tested on coronal images of the rotator cuff in a series of 144 patients, and the improvements in image quality were similar to those achieved with navigator echoes. The results demonstrate that autocorrection can significantly reduce motion artifacts in a technically demanding MR imaging application.

Health profiles in quality of life: evaluation of diagnostic technologies

The use of instruments to measure health-related quality of life has become commonplace in medical research, although their use is still unusual in the evaluation of diagnostic technologies. Dr Greenfield has pointed out the potential to abuse as well as use these methods. The cautions that Dr Greenfield has outlined apply to any such research, whether one is evaluating a new drug or a new imaging device. Even though the chain of events from diagnostic technology to patient outcome is longer than for therapeutic interventions, we maintain that quality-of-life instruments are potentially valuable tools for evaluating any of the links in this chain.

Imaging of the cervical spine

The emergence of multiplanar spiral computed tomography and high-resolution magnetic resonance imaging has resulted in the ability to see cervical spine anatomy and pathologic conditions in detail. Appropriately chosen and performed, these imaging studies can provide an anatomic basis for a clinical diagnosis and a therapeutic plan. In the evaluation of cervical spondylosis, magnetic resonance imaging is more commonly performed than computed tomography because of its superior depiction of soft tissue anatomy, including intervertebral discs and spinal cord disease. However, computed tomography still has a role, particularly in the assessment of osseous neural foraminal stenosis. In cervical spine trauma, routine radiography remains the procedure of choice. Computed tomography is performed in patients who have abnormal plain radiographs or in patients in whom there is a strong clinical suspicion of fracture with inconclusive radiographs. In the neurologically compromised patient, magnetic resonance imaging is useful in the diagnosis of cord and nerve root injury. Magnetic resonance imaging is the most sensitive and specific imaging study in the assessment of spinal infection, including osteomyelitis, discitis, and epidural abscess. Magnetic resonance imaging has also supplanted all other imaging methods in the evaluation of primary and secondary tumors of the spinal cord and spinal column. Despite the precise depiction of cervical spine anatomy provided by these imaging methods, the role of the clinician in determining the true cause of a patient's symptoms is in no way diminished. The presence of an imaging study abnormality does not automatically imply causality.

Suspected spinal cord compression in breast cancer patients: a multidisciplinary risk assessment

Breast cancer is the most common cause of metastatic epidural spinal cord compression (SCC) in women, and this condition results in significant neurologic dysfunction and morbidity. Prior studies of patients with suspected SCC did not employ multivariate analysis techniques, often included persons with a wide variety of malignancies, and generally focused on identifying associated neurologic and radiologic features. We therefore conducted a study examining a more comprehensive set of potential clinical risk factors in breast cancer patients with suspected SCC. We retrospectively analysed 123 episodes of suspected SCC among 93 breast cancer patients evaluated by spine computed tomography (CT) scanning. Multiple logistic regression analysis was employed to identify independent predictors of SCC. Clinically significant metastatic epidural cancer was defined as thecal sac compression (TSC), which occurred in 33 episodes (27%). Four independent predictors of TSC were identified and included oncologic features (known bone metastases > or = 2 years, metastatic disease at initial diagnosis) in addition to neurologic and radiologic features (objective weakness, vertebral compression fracture on spine radiograph). These four predictors stratified episodes into subgroups with widely varying risks of TSC, ranging from 12% (0 risk factors) to 85% (> or = 3 risk factors). These results suggest that the evaluation of breast cancer patients with suspected SCC should include clinical information about their disease course in addition to neurologic examination and prior imaging studies. If confirmed, these predictors may help clinicians assess risk in this patient population.

Spinal cord compression in prostate cancer: treatment outcome and prognostic factors

BACKGROUND AND PURPOSE

Spinal cord compression (SCC) is an important complication of metastatic prostate cancer. We have analysed patients treated at the Royal Marsden Hospital to assess treatment outcome and prognostic factors in this patients group.

MATERIALS AND METHODS

We performed retrospective analysis of 69 patients with spinal cord compression and prostate cancer treated at the Royal Marsden Hospital.

RESULTS

At presentation 40 (58%) patients were non-ambulant and 52% were catheterised. Diagnosis was established by myelography in 42% and magnetic resonance imaging (MRI) in 47% of patients. MRI detected significantly more patients with multiple sites of compression (51 versus 7%, P < 0.001). SCC was present at the initial diagnosis of prostatic cancer in 13 patients and 17 patients had received no hormone treatment prior to diagnosis. Following treatment 36 (52%) patients had a functional improvement of motor power with 25/40 (63%) non-ambulant patients becoming ambulant. Seventy-seven percent of patients who had eventual improvement had some improvement in power within 7 days. On multivariate analysis a single level of compression, no previous hormone therapy and a young age (<65 years) predicted for better outcome. When these factors were included an increased radiation dose (>30 Gy) or the addition of surgery did not improve the functional outcome. Following initial recovery; there was a 45% risk of developing a further episode of cord compression at the same or new site by 2 years with a median time to progression of 236 days (range 47-1215 days). The median survival was 115 days (range 5-2016 days) with 25% of patients surviving for 2 years. Patients with no prior hormone therapy had a median survival of 627 days (range 46-1516 days). Other predictors of improved survival on multivariate analysis were a single site of compression and a haemoglobin over 12 g.

CONCLUSIONS

Treatment of SCC in prostate cancer results in improved motor function in the majority of patients. Long-term survival is possible, especially in good performance status patients with no prior hormone treatment. Survivors remain at high risk of subsequent neurological relapse. An early improvement in motor power is a strong predictor of subsequent functional improvement. MRI detects additional sites of asymptomatic SCC which makes it the investigation of choice.

Oncologic emergencies

The prognosis for the child with cancer has improved dramatically over the past decades. With this success comes the need for recognition and proper treatment of emergencies. Respiratory or circulatory failure may arise from compression of the SVC or airway. Epidural spinal cord compression by tumor may lead to irreversible paraplegia or urinary incontinence if intervention is not rapid. Raised intracranial pressure may be a life-threatening presentation of a brain tumor. Bone marrow failure, with anemia and thrombocytopenia, is associated with malignant infiltration of the marrow. Hyperleukocytosis carries a high risk of thrombotic events if not treated promptly. Coagulation abnormalities are seen in many childhood cancers at the time of diagnosis. Life-threatening metabolic abnormalities are observed at presentation in children with leukemia and lymphoma. Hypercalcemia, although rare, may be a difficult situation to correct. Immediate attention to these emergencies and appropriate treatment may save the life of a child with cancer or make his or her subsequent course just a little smoother.

Radiotherapy for palliation of symptoms in incurable cancer

Approximately one half of prescribed radiotherapy is given for palliation of symptoms due to incurable cancer. Distressing symptoms including pain, bleeding, and obstruction can often be relieved with minimal toxic effects. Painful osseous metastasis is common in oncologic practice. Ninety percent of patients with symptomatic bone metastases obtain some pain relief with a lowdose, brief course of palliative radiotherapy. One half of the responding patients may experience complete pain relief. A single dose of 800 cGy in the setting of painful bone metastasis may provide pain control comparable to more protracted treatment at a higher dose of radiation. Patients with lytic disease in weight-bearing bones, particularly in the presence of cortical destruction, should be considered for prophylactic surgical stabilization of their condition. Routinely a brief, fractionated course of radiotherapy is given postoperatively. Pain due to multiple bone metastases uncontrolled by analgesics can be managed with single doses of halfbody irradiation. Doses of 600 cGy delivered to the upper half-body (above the umbilicus) and 800 cGy to the lower half-body (from the umbilicus to the middle of the femur) will provide some pain relief in 73% of patients. Half-body techniques have been investigated as prophylactic treatment, as a complement to local-field irradiation, and as fractionated rather than singledose therapy. Although intravenous administration of strontium 89 has been associated with myelosuppression, this treatment has been shown (a) to relieve pain due to bone metastasis and (b) to delay development of new painful sites. Recent data from phase III trials demonstrated that bisphosphonates have a role in reducing skeletal morbidity due to bone metastasis. Bone pain was reduced, and the incidence of pathologic fracture and the need for future radiotherapy was decreased. Radiotherapy relieves clinical symptoms in 70% to 90% of patients with brain metastases. Brief treatment schedules (e.g., 2000 cGy in five fractions over 1 week) are as effective as more prolonged therapy. Patients with solitary brain metastasis and no extracranial disease or controlled extracranial disease should be considered for surgical resection, because phase III data indicate enhanced survival with such an approach. Whole-brain radiotherapy is routinely administered postoperatively. A phase III study is examining the impact of accelerated fractionated doses of radiotherapy (two treatments per day) on survival of patients with brain metastases. Stereotaxic radiosurgical treatment is becoming increasingly available and permits delivery of radiation to metastatic intracranial tumor with minimal exposure of normal surrounding brain This treatment is most commonly used at the time of a solitary recurrence of disease in patients who previously received whole-brain radiotherapy. A role for this modality in newly diagnosed brain metastases remains to be defined. Chest symptoms are common in patients with locally advanced lung cancer and are effectively palliated with one 1000 cGy or two 850 cGy one fraction doses of radiation to the thoracic inlet and mediastinum. Chest pain and hemoptysis are more effectively palliated than cough and dyspnea. In patients with stage III cancer there is no compelling evidence that radiotherapy confers a survival advantage, and it may be reasonable to administer thoracic radiotherapy only when the patient has significant symptoms and the goal is to achieve control of these symptoms. Approximately 75% of the cases of superior vena cava syndrome are due to lung cancer, and small-cell lung cancer is the most common histologic type. A histologic diagnosis should be obtained before treatment is started, because detection of lymphoma or small-cell carcinoma would necessitate systemic therapy. Eighty percent of the patients with vena cava syndrome due to malignant disease achieve symptom relief with a brief, fractionated, palliative course of rad

Central nervous system metastasis in breast cancer

BACKGROUND AND PURPOSE

Central nervous system (CNS) metastasis occurs in at least 30% of patients with breast cancer. Standard treatment is the same as in other solid tumors, though clinical behavior, and sensitivity to radiation therapy (RT) and to chemotherapy may differ considerably. Most of these patients die within a few months, but a substantial subgroup may survive a year or more. The last decade has given rise to new diagnostic methods, new surgical and radiotherapeutic techniques, and the clinical evidence of a chemotherapy permissive blood-brain barrier in CNS metastases. The literature was reviewed to assess the clinical impact of early diagnosis, recognition of prognostic factors, and of the recently developed therapeutic approaches.

MATERIAL AND METHODS

Review of the literature on CNS involvement in breast cancer focusing on clinical studies on early diagnosis, new modes of treatment, and factors influencing outcome.

RESULTS

Although randomized studies are still awaited, systemic chemotherapy seems a valuable alternative for RT of brain metastases in selected cases. In meningeal carcinomatosis, long survival may be independent of intraventricular chemotherapy. Neurotoxicity of intensive intraventricular treatment is considerable. In epidural metastasis, early diagnosis with prompt start of treatment remains the crucial factor for outcome. Radiation therapy is the mainstay of treatment of epidural metastasis, but new surgical techniques and even systemic chemotherapy should be considered in selected cases.

CONCLUSIONS

Recognition of prognostic factors combined with appropriate use of various recently developed therapeutic possibilities will improve the clinical outcome including better local tumor control and less treatment-induced neurotoxicity in a considerable number of patients with CNS metastasis from breast cancer.

Effectiveness of radiation therapy without surgery in metastatic spinal cord compression: final results from a prospective trial

PURPOSE

In assessing effectiveness of radiation therapy (RT) in metastatic spinal cord compression (MSCC), we performed a prospective trial in which patients with this complication were generally treated with RT plus steroids, and surgery was reserved for selected cases.

METHODS AND MATERIALS

Two hundred seventy-five consecutive patients with MSCC entered this protocol. Twenty (7%) underwent surgery plus RT, another 255 received RT alone. Of all eligible patients, 25 (10%) early deaths and 21 (8%) entering a feasibility study of RT without steroids, were not evaluable. Of the 209 evaluable cases, 110 were females and 99 males, and median age was 62 years. Median follow-up was 49 months (range, 13 to 88) and treatment consisted of 30 Gy RT (using two different schedules) together with steroids (standard or high doses, depending on motor deficit severity). Response was assessed according to back pain and motor and bladder function before and after therapy.

RESULTS

Back pain total response rate was 82% (complete or partial response or stable pain, 54, 17, or 11%, respectively). About three-fourths of the patients (76%) achieved full recovery or preservation of walking ability and 44% with sphincter dysfunction improved. Early diagnosis was the most important response predictor so that a large majority of patients able to walk and with good bladder function maintained these capacities. When diagnosis was late, tumors with favorable histologies (i.e., myeloma, breast, and prostate carcinomas) above all responded to RT. Duration of response was also influenced by histology. Favorable histologies are associated to higher median response (myeloma, breast, and prostate carcinomas, 16, 12, and 10 months, respectively). Median survival time was 6 months, with a 28% probability of survival for 1 year. Survival time was longer for patients able to walk before and/or after RT, those with favourable histologies, and females. There was agreement between patient survival and duration of response, systemic relapse of disease being generally the cause of death.

CONCLUSION

Early diagnosis of MSCC was a powerful predictor of outcome. Primary tumor histology had weight only when patients were nonwalking, paraplegic, or had bladder dysfunction. The effectiveness of RT plus steroids in MSCC emerged in our trial. The most important factors positively conditioning our results were: the high rate of early diagnoses (52%) and the number of tumors with favorable histologies (124 out of 209, 63%) recruited, and the choice of best treatment based on appropriate patient selection for surgery and RT or RT alone.

CT and MRI of the normal and diseased perivertebral space

The perivertebral space is in the midline, in the deep tissues of the neck, and can be identified from the skull base above to the mediastinum below. It is a discrete space completely enclosed by the deep layer of deep cervical fascia. The fascial attachments of the perivertebral space divide it into two areas, the anterior prevertebral and posterior paraspinal portions. We made a retrospective analysis of the radiologic and clinical records of 52 patients with lesions in the perivertebral space, to identify the imaging features that mark a lesion as originating in the perivertebral space and define the spectrum of pathology which occurs in the space. Mass lesions present in the prevertebral or paraspinal portions. In the former they usually involve the vertebral body, displacing the prevertebral muscles anteriorly. Epidural extension from lesions in the perivertebral space proper is common. Masses in the paraspinal perivertebral space usually displace the paraspinal muscles away from the spine. We found 9 inflammatory lesions, 29 malignant and 6 benign tumors, and 8 miscellaneous lesions.

Cost effectiveness and outcome assessment of magnetic resonance imaging in diagnosing cord compression

BACKGROUND

This study was designed to investigate the costs associated with the use of magnetic resonance imaging (MRI) in the workup of spinal cord compression caused by metastatic disease, an area in which it has proven to be diagnostically useful.

METHODS

The study was divided into two parts. Part 1 consisted of a retrospective review of the hospital charts of 46 patients, half of whom were diagnosed with cord compression in the pre-MRI era and the other half diagnosed after MRI availability; costs for these two groups were compared. Part 2 consisted of a review of several major studies comparing the sensitivities and specificities of MRI with alternative imaging techniques, usually myelography. Cost effectiveness and cost/cost ratios were derived for diagnostic usefulness using prevalence, sensitivity, specificity, and cost estimates of MRI and its alternatives, including costs of false-negative and false-positive testing.

RESULTS

Our hospital-based experience yielded an average cost of $ 3664 per patient without MRI and $ 2283 per patient when MRI was available (1991 dollar amounts). The cost of diagnosis was 65% more expensive without MRI. Use of the literature-based experience demonstrated that the cost of diagnosis was at least 82% more costly without MRI than when it was available. However, when key variables were altered during sensitivity analysis, this difference of increased cost of diagnosis without MRI ranged from 25% to 98%.

CONCLUSION

This work suggests that MRI may result in significant economic benefits in diagnosing metastatic cord compression, but further work is needed on physician behavior and referral patterns with MRI versus myelography as is long term follow-up for potential reductions in patient debility using MRI.

Magnetic resonance imaging in spinal emergency

We studied the diagnostic value of MRI in spinal emergency. One hundred patients were analyzed retrospectively and the MR-findings were compared with operative results or autopsy whenever available. The advantages of MRI compared to CT and conventional myelography are discussed. The limitations of MRI are addressed and the important features of appropriate diagnostic procedure are outlined with special attention to neurosurgical requirements.

Spinal cord compression in prostate cancer

Approximately 200,000 men will be diagnosed with prostate cancer in 1994. While localized disease is potentially curable with surgery or radiation therapy, metastatic disease is incurable. The most frequent site of metastasis is bone. Spinal cord compression occurs in approximately 7% of men with prostate cancer. Back pain often heralds the diagnosis of spinal cord compression. In prostate cancer patients with back pain or signs of myelopathy or radiculopathy, plain radiographs of the spine and magnetic resonance imaging should be performed. Early diagnosis is of utmost importance. The neurologic status prior to treatment is the major determinant influencing outcome. Following diagnosis, corticosteroid therapy should begin immediately. Hormonal therapy should be instituted in those patients who have not previously undergone hormonal manipulation. The standard approach to definitive therapy is radiation. Surgical decompression plays a role in patients with severe myelopathy, spinal instability, and in those patients whose neurologic status deteriorates during or after radiation therapy.

Extradural causes of myelopathy

Myelopathy, the rapid or insidious onset of motor and sensory abnormalities referable to the spinal cord, occurs as a result of a variety of causes that may be classified on the basis of their location of origin (intramedullary, intradural-extramedullary, and extradural). The first goal of imaging is to appropriately assign the observed abnormality to its location of origin and, therefore, into the correct diagnostic list. This article focuses on the plain film, computed tomography, and magnetic resonance demonstration of extradural causes of myelopathy.