False-negative bone scan in extensive metastatic disease: CT and MR findings

Total body MRI-governed involved compartment irradiation combined with high-dose chemotherapy and stem cell rescue improves long-term survival in Ewing tumor patients with multiple primary bone metastases

We examined the role of total body magnetic resonance imaging (TB-MRI)-governed involved compartment irradiation (ICI) and high-dose chemotherapy (HDC), followed by stem cell rescue (SCR) in patients with high-risk Ewing tumors (ETs) with multiple primary bone metastases (high-risk ET-MBM). Eleven patients with high-risk ET-MBM receiving initial assessment of involved bones by TB-MRI were registered from 1995 to 2000 (group A). In all, 6 patients out of 11 had additional lung disease at initial diagnosis; all had multifocal bone disease with more than three bones involved. After systemic induction with etoposide, vincristine, adriamycin (doxorubicin), ifosfamide, and actinomycin D (EVAIA) or VAIA chemotherapy, ICI of all sites positive by TB-MRI was administered, followed by HDC and SCR. A second group matched for observation period and consisting of 26 patients with more than three involved bones at diagnosis was treated with the European Intergroup Cooperative Ewing Sarcoma Study-92 (EICESS-92) protocol (group B). These patients did not receive TB-MRI and consequently did not receive TB-MRI-governed ICI, or HDC and SCR. Survival in group A vs group B was 45 vs 8% at 5 years and 27 vs 8% at 10 years after diagnosis (log rank and Breslow: P<0.005). We conclude that TB-MRI-governed ICI followed by HDC and SCR in ET-MBM is feasible and warrants further evaluation in prospective studies.

Factors Influencing Visualization of Vertebral Metastases on MR Imaging Versus Bone Scintigraphy

OBJECTIVE

The purpose of this study was to investigate whether the location and size of vertebral body metastases influence the difference in detection rates between MR imaging and bone scintigraphy.

MATERIALS AND METHODS

We retrospectively evaluated the vertebral body lesions detected on MR imaging in 74 patients with known widely disseminated metastatic disease. Three radiologists independently reviewed the MR images and bone scintigraphs. MR imaging findings included lesion size and its spatial relationship to the bony cortex (intramedullary, subcortical, and transcortical) and results were correlated with those of planar technetium 99m bone scintigraphy.

RESULTS

Findings on bone scans were negative for all intramedullary lesions without cortical involvement shown on MR imaging, regardless of their size. Findings on bone scans (71.3% for transcortical and 33.8% for subcortical) were frequently positive for lesions with cortical involvement (trans- or subcortical), and the probability of positive findings on bone scans was also influenced by the lesion size. Statistical analysis showed a positive correlation among cortical involvement, lesion size, and positive findings on bone scintigraphy (p < 0.0001).

CONCLUSION

Location (the presence of cortical bone involvement on MR imaging) and size of the vertebral body metastases appear to be important contributing factors to the difference in detection rates between MR imaging and bone scintigraphy. Cortical involvement is likely the cause of positive findings on bone scans. Early vertebral metastases tend to be small and located in the medullary cavity without cortical involvement, and therefore, findings may be positive on MR images but negative on bone scans.

Early response of breast cancer bone metastases to chemotherapy evaluated with MR imaging

PURPOSE

To compare T1-weighted spin-echo and fat-suppressed long echo time inversion recovery turbo spin-echo (long TE IR-TSE) MR images in the evaluation of early response of breast cancer bone metastases to chemotherapy.

MATERIAL AND METHODS

Eighteen breast cancer patients with known bone metastases were investigated prospectively by MR, using T1-weighted and long TE IR-TSE sequences on the sternum, spine, pelvis and proximal femora, before and after a median of 6 courses of chemotherapy. Therapeutic response evaluation with MR was based on change in tumor size assessed quantitatively by measuring all focal metastases, and change in pattern and signal intensity (SI) of the metastases, assessed visually. Combined response evaluation based on clinical findings, conventional radiography, and scintigraphy was used as reference.

RESULTS

Progressive disease (2 patients) and no change (4 patients) were assessed equally well on both MR sequences. Long TE IR-TSE demonstrated partial response with higher accuracy than T1-weighted images, 58% (7/12 patients) vs. 17% (2/12 patients). In patients without progression there was an SI increase in or around the metastases in 6 patients on T1-weighted images and in 7 patients on long TE IR-TSE images.

CONCLUSION

The long TE IR-TSE sequence demonstrated early partial response of breast cancer bone metastases to chemotherapy more accurately than the T1-weighted sequence.

The usefulness of 99mTc-HMPAO-labeled leukocyte scintigraphy in the diagnosis of skeletal metastases of cancers

The usefulness of bone marrow scintigraphy with 99mTc-HMPAO-labeled leukocytes (leukocyte bone marrow scintigraphy) in the diagnosis of skeletal metastases of cancers was investigated in 70 lesions in 27 patients with various types of cancer. The final diagnosis of skeletal metastases was based on one or more criteria consisting of histological confirmation, typical findings of metastases by bone radiograph, CT and MRI, or progressive swellings of the lesions with severe pain due to nerve compression. Of the 70 lesions, 55 were finally diagnosed as metastases, and 15 as benign lesions. Leukocyte bone marrow scintigraphy showed photopenic defects in 52 of the 55 metastatic lesions (sensitivity 95%), and the remaining 3 negative lesions were found positive for metastases by MRI. In contrast, MRI could evaluate only 39 of the 55 lesions because 16 lesions in the ribs, scapula and sternum were not visualized. Of these 39 lesions, MRI showed positive findings for metastases in 33 (sensitivity 85%), and negative findings in 6 with photopenic defects found by leukocyte bone marrow scintigraphy. Of the 15 benign lesions, 3 were false positive for metastases on leukocyte bone marrow scintigraphy (specificity 80%). We conclude that 99mTc-HMPAO-labeled leukocyte bone marrow scintigraphy may be useful in the diagnosis of skeletal metastases of cancers, particularly when MRI fails to evaluate the lesions.

Imaging bronchogenic carcinoma

Imaging plays an integral role in diagnosing, staging, and following patients with lung cancer. Most lung tumors are detected on chest radiographs, but unfortunately, the majority of patients have advanced stage disease at presentation. There is a wide spectrum of radiologic manifestations of lung cancer, and recognition of these findings is essential for patient management. As we continue to understand more about tumor biology, new imaging techniques should emerge and have the potential to significantly improve our diagnostic capabilities.

Magnetic resonance imaging versus radionuclide scintigraphy in screening for bone metastases

AIM

To determine the frequency of isolated, asymptomatic metastases of the peripheral skeleton in patients with breast and prostate cancer.

METHODS

A retrospective review was performed of staging skeletal scintigrams. Patients with hot spots in the peripheral skeleton in the absence of convincing evidence of metastatic disease in the axial skeleton were followed-up to determine the nature of the peripheral lesion(s) based on other imaging modalities, serial imaging or biopsy, and to determine if the lesion(s) had been symptomatic at the time of the scintigram.

SUBJECTS

200 patients with histologically proven carcinomas of the breast or prostate.

RESULTS

Four patients (2%) had isolated metastatic involvement of the peripheral skeleton, and would, therefore, have been wrongly staged by a magnetic resonance 'marrow screen' of the axial skeleton. However, in three of these patients the lesions were painful, prompting diagnostic plain radiographs independent of the scintigraphic findings. Twelve patients (6%) had isolated scintigraphic abnormalities of the peripheral skeleton suggestive of metastatic disease but which on further investigation were shown to be benign lesions.

CONCLUSION

A limited magnetic resonance (MR) 'marrow screen' confined to the axial skeleton would not result in any significant loss of accuracy in staging patients with breast and prostate carcinoma compared with skeletal scintigraphy. Given the proven increased sensitivity of MR over skeletal scintigraphy in the detection of bone metastases, and the additional information MR provides, it is likely to provide a more accurate basis for management.

Total-body echo-planar MR imaging in the staging of breast cancer: comparison with conventional methods--early experience

PURPOSE

To test breast cancer staging with total-body echo-planar magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Nineteen patients with newly diagnosed breast cancer were imaged by using a 1.5-T echo-planar MR system. By using a table sweep method, 180 contiguous axial images were obtained from the cranial vertex through the feet with T2-weighted spin-echo and inversion-recovery sequences. Results were compared with those of conventional imaging. Therapeutic decisions based on echo-planar MR imaging and conventional imaging results were compared. Diagnostic truth was determined by means of tissue diagnosis, further imaging findings, and follow-up findings (median, 18 months).

RESULTS

Staging with total-body echo-planar MR imaging was correct in 18 patients (95%)--eight with metastases and 10 without--while staging with conventional imaging was correct in 15 patients (79%). In one patient, both echo-planar MR imaging and conventional imaging findings incorrectly indicated probable metastases. In one patient thought to have bone metastases at conventional imaging, echo-planar MR imaging findings were normal, which was correct. Two patients with stage IV disease were not suspected to have disease at conventional imaging: One had liver involvement and the other had skeletal metastases. The therapeutic decisions in these two patients were altered by the echo-planar MR imaging results.

CONCLUSION

Total-body echo-planar MR imaging was at least as accurate as conventional imaging for staging newly diagnosed breast cancer and was faster, simpler, and completely noninvasive.

Whole-body bone marrow MRI in patients with metastatic disease to the skeletal system

PURPOSE

The purpose of this study was to evaluate the diagnostic potential of a whole-body bone marrow MR protocol in the detection of bone metastases.

METHOD

Whole-body bone marrow MRI was performed in 18 patients with known malignant tumors and suspected bone metastases. The imaging protocol consisted of fast T1-weighted and STIR sequences applied in different anatomical positions covering the whole skeleton. MRI findings indicating bone metastases were compared with findings from bone scintigraphy. Metastatic lesions were confirmed by follow-up MR examinations, bone scintigraphy, radiography, or CT.

RESULTS

A total number of 216 lesions were detected with MRI in comparison with 159 lesions detected with bone scintigraphy. Follow-up examinations confirmed 105 lesions. MRI detected 96 (91.4%) of the confirmed lesions, whereas bone scintigraphy detected 89 (84.8%). The entire examination, including patient positioning and changing of imaging coils, required 45 min of room time.

CONCLUSION

Whole-body bone marrow MRI as used in this study is an effective method for evaluating the entire skeletal system in patients with suspected metastatic disease.

T1-weighted magnetic resonance imaging in breast cancer vertebral metastases: changes on treatment and correlation with response to therapy

PURPOSE

To document the MR appearances of vertebral metastases in breast cancer on treatment and to determine whether a single T1-weighted (T1-W) sequence of the spine could provide a quick and effective method of response assessment.

PATIENTS AND METHODS

One-hundred and nine spinal magnetic resonance (MR) examinations in 41 metastatic breast cancer patients on treatment were reviewed. The changes in number, size and signal intensity of vertebral metastases during 68 intervals (mean length 6.9 months) were documented. T1-W signal intensity (SI) before and after treatment was assigned to three patterns: (A) low homogeneous SI; (B) low heterogeneous SI; and (C) high homogeneous SI. For each interval between MR examinations, an objective assessment of the overall response (disease regression, no change, disease progression) to treatment of metastases was made based on standard assessment criteria.

RESULTS

The number and size of treated vertebral metastases increased in 47% and 43% of cases and showed no change in 53% and 54% of cases, respectively. A reduction in size of lesions was seen in 3% of cases only and no reduction in the number of lesions was seen. T1-W [corrected] signal intensity changes occurred in approximately one-third of cases documented. The most commonly observed SI change in 25% of all intervals (17 of 68) was from type A to type B. There was no correlation between SI change and response to therapy. T1-W [corrected] MR response assessment, based on changes in size and number of vertebral metastases, accurately predicted progression of disease in 79% of cases and stable disease in 75% of cases. It did not predict regression of disease.

CONCLUSION

A T1-W MR spinal assessment is a simple and effective method of evaluation of therapeutic response of lytic and sclerotic vertebral metastases in breast cancer being able to distinguish patients with progressive disease from those with a favourable response (no change or disease regression) to therapy. These findings have important clinical implications.

Diagnostic bone scanning in oncology

Over the last several decades bone scanning has been used extensively in the evaluation of oncology patients to detect bone involvement. It can provide information about disease location, prognosis, and the effect of therapy. Bone scanning offers the advantages of whole body evaluation and the detection of lesions earlier than other techniques. However, as newer diagnostic tools become available, indications for bone scanning must be revised and the results combined with these other tests in order to provide optimum patient care. Advances in instrumentation and the subsequent improvement in image quality have allowed nuclear medicine physicians to provide more accurate bone scan interpretations. By optimizing image acquisition, it is often possible to determine lesion characteristics, which are more likely to represent malignancy. Knowledge of disease pathophysiology and other specific properties of the patient's primary tumor, along with subsequent correlation of scan abnormalities to patient history, physical examination, previous studies, and other radiological examinations, is essential for determining lesion significance. The differential diagnosis of a scan abnormality should also include consideration of both false normal and abnormal causes. The final interpretation should be clearly communicated to the clinician with appropriate recommendations for further evaluation. Only through careful attention to the patient, the clinician, and appropriate study acquisition parameters will bone scanning maintain its place in the evaluation of oncology patients.

Detection of bone marrow metastases in small cell lung cancer. Comparison of magnetic resonance imaging with standard methods

In small cell lung cancer (SCLC), bone marrow metastases are frequently detected by bone scintigraphy (BS) and/or unilateral bone marrow biopsy and aspiration (BMBA). In this study, the value of magnetic resonance imaging (MRI) of thoracic spine and pelvis was compared with BS and BMBA and its clinical implication was evaluated in 42 patients with SCLC. Patients were staged (including BS, BMBA, CT thorax, Liver ECHO) as limited (LD) or extensive disease (ED) before and after MRI. MRI was positive in 12 BS negative (P = 0.003) and in 14 BMBA negative patients (P < 0.001), while in 8 patients, MRI was the only sign of ED, which resulted in a decrease of patients categorised with LD from 52 to 33%. However, in this small group of LD patients, there was no significant survival difference between LD (MRI pos) and LD (MRI neg) patients. It is concluded that MRI can be of value in the staging of LD patients, but it has no influence on survival.

The value of bone scintigraphy, bone marrow scintigraphy and fast spin-echo magnetic resonance imaging in staging of patients with malignant solid tumours: a prospective study

The purpose of this prospective study was to define the value of bone scintigraphy (BS), bone marrow scintigraphy (BMS) and the new fast spin-echo (FSE) magnetic resonance imaging (MRI) sequences in screening for bone metastases in patients with solid malignant tumours. It was our particular interest to classify patients into a group with and a group without bone metastases, and not only to compare the absolute number of metastases detected by each method. Thirty-two patients were examined using technetium-99m dicarboxy propane diphosphonate bone scintigraphy, 99Tc-labelled monoclonal anti-granulocyte antibodies for bone marrow scintigraphy and 1.5 T MRI using T1-weighted and FSE T2-weighted sequences. Against a reference standard obtained by re-evaluation of all clinical and imaging data 1 year after prospective BS, BMS and MRI had been performed, the three imaging modalities were falsely positive in two, eight and two cases and falsely negative in zero and four cases, respectively. BMS was falsely positive in eight patients because of vertebral marrow degeneration which caused photopenic defects which could not be differentiated from metastases. MRI showed these lesions to unequivocally contain fat. BMS and MRI were falsely negative in four cases because of the limited field of examination. In our study the key factor in classifying a patient as bone M1 or M0 was the possibility of surveying the entire skeleton, as is the case in BS, and not that MRI had a higher sensitivity compared to BS when analysis was on a lesion-by-lesion basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging for detection of prostate cancer metastatic to bone

The diagnosis of prostate cancer metastatic to bone currently is made with plain x-rays, radionuclide bone scans, and acid and alkaline phosphatases. We used magnetic resonance imaging (MRI) in 18 patients with known prostate cancer to resolve conflicting evidence of metastases found on bone scans, plain films and serum enzyme determinations. Of 8 bone scans interpreted as positive MRI was read as negative for metastatic disease in 2. Of 5 negative bone scans 1 MRI study was interpreted as positive. All 5 equivocal bone scans demonstrated no osseous lesions on MRI. In addition, in 6 patients with evidence of bone metastases the serial MRI scans following hormonal therapy demonstrated radiographic and clinical improvement. We conclude that MRI is helpful in the diagnosis of metastatic prostate cancer when other radiographic examinations are enigmatic and that MRI can be used to determine the response to hormonal treatment.

Modern imaging methods in oncology

Modern imaging methods are very important in the management of patients with cancer and of their disease. It is vital that clinicians treating them understand the relevance of different imaging techniques for specific applications, so that the best choice can be made to aid diagnosis and monitor response to treatment. This review briefly covers the development and principles of the diverse imaging methods available, from the discovery of x-rays by Röntgen in 1895 to the recent techniques of magnetic resonance and positron emission tomography. The authors endeavour to point out the strengths and weaknesses of each method, using clinical examples where appropriate. Finally, future developments are discussed. It is hoped that this review will aid clinicians diagnosing and treating cancer patients to choose the most suitable imaging method for their patients from among the vast array available.

Spinal MR imaging in suspected metastases: correlation with skeletal scintigraphy

Bone scintigraphy (RN) and magnetic resonance imaging (MR) were prospectively and retrospectively correlated in 64 patients with suspected spinal metastatic disease and possible spinal cord compression. Images were retrospectively interpreted and compared with the prospective official RN and MR reports to help decide relative prospective lesion conspicuity. Spinal lesions were confirmed by radiography, computed tomography, myelography or MR and RN follow-up in 56 patients (88%). Prospectively, MR detected 11 lesions not reported on RN while RN detected two lesions not reported on MR. Retrospective review of RN detected six lesions previously not reported. Retrospectively MR showed all lesions. Those lesions seen only in retrospect by RN were rather subtle and would be difficult to detect prospectively. In general, lesions not well seen on RN had relatively more bone marrow abnormality and less cortical bone involvement. In some cases, MR imaging shows spinal marrow lesions not well seen on planar RN.