[Whole-body MRI in comparison to skeletal scintigraphy for detection of skeletal metastases in patients with solid tumors]

[Cost considerations for whole-body MRI and PET/CT as part of oncologic staging]

PURPOSE

The aim of this study was to evaluate and discuss economic aspects of whole-body MRI and PET/CT in oncologic staging. Considerations from the perspective of the health care system, the radiologist, and the patients are presented.

MATERIALS AND METHODS

Costs of both whole-body techniques are compared with the conventional radiologic diagnostic recommendations of the AWFM (Arbeitsgemeinschaft Wissenschaftlich Medizinischer Fachgesellschaften) in oncologic staging of the five most frequent tumor entities. Temporal and monetary aspects are calculated. Invasive, endoscopic, and endosonographic techniques are regarded as essential and cannot be replaced by other techniques. Thus only the minimal potential for cost reduction is quantified.

RESULTS

In the German system there is no cipher to correctly balance whole-body MRI and PET/CT. Using the frequently applied ciphers 5700-5730 and 5378, 5489 (factor 1.0) total costs were 440.45 euros, and adding the cipher for additional series 545.37 euros (60 min examination time) for whole-body MRI and 774.74 euros (879.66 euros) (60/90 min examination time) for whole-body PET/CT. Using the common factor 1.8 costs were 981.66 and 1583.38 euros. On the basis of a simple full cost analysis total costs of whole-body PET/CT were higher than of whole-body MRI by a factor of about 2.0 (about 1123 vs 575 euros). There were substantial monetary and temporal differences between tumor entities. In extended bronchial carcinoma 375.32 euros and 55 min can be saved using whole-body MRI in comparison to conventional recommended techniques and using whole-body PET/CT 88.14 euros and 45 min. In tumor entities of lower stages with thus less essential radiologic diagnostics the potential for cost reduction is substantially lower.

CONCLUSION

Whole-body imaging techniques make it possible to reduce the number of necessary separate radiologic examinations and thus time in oncologic staging. A substantial reduction of health care costs seems to be possible in many tumor entities but differences between different tumor entities are decisive.

[Whole body MRI--diagnostic strategy of the future?]

Whole body magnetic resonance imaging (MRI) opens new opportunities in diagnostic radiology as systemic disease entities can be examined with high sensitivity. This can lead to a change of paradigm, so that not only organ-related but rather disease-specific MRI examination protocols can be applied which focus on the underlying pathophysiology of the disease. Whole body MRI has already been successfully used for several oncological and non-oncological indications. In addition, whole body MRI has broadened the discussion regarding its use for secondary prevention. Compared to computed tomography, MRI does not use radiation. Although whole body MRI is still in an early stage, the enormous medical and economical potential can be envisioned.

[Screening in cardiovascular diseases]

Cardiovascular disease still ranks number one in the mortality statistics in the industrialized world. In Germany the five most common causes of death are all associated with arteriosclerotic changes of the arterial vasculature. As the treatment often extends over long periods and it can be impossible for patients to work, peripheral arterial occlusive disease (PAOD) constitutes a not inconsiderable economic factor. Thus, screening for arteriosclerotic disease seems to be reasonable, because the potential for influencing arteriosclerotic changes is known to be higher in an early stage of the disease even before symptoms become apparent. Not every case can be cured, but progression can frequently be slowed down. The need for invasive procedures, some of them associated with ionizing radiation, limited the use of imaging of the arterial vasculature for a long time. Noninvasive clinical examinations such as the "ankle brachial index" (ABI) can indicate the presence of PAOD, though exact localization of the pathologic changes is not possible except with imaging methods. In contrast to these, MRI is a noninvasive imaging modality that does not involve ionizing radiation but offers high spatial resolution arterial imaging.

[Magnetic resonance imaging in orthopaedic medicine]

Magnetic resonance imaging (MRI) is an established diagnostic tool in orthopaedics. Superior soft tissue contrast, lack of ionised radiation and free slice orientation are the key points for optimal evaluation of joint structures, muscles and ligaments. Application of contrast agents improves the detection of inflammation and tumour tissue. However, measuring and interpretation of magnetic resonance imaging is a challenge both for orthopaedists and radiologists. Basic requirements for good diagnosis are clinical findings, plain radiographs and a clear indication. This report provides information about the method of magnetic resonance imaging, artefacts, indications, risks and drawbacks as well as limitations of this method that necessitate alternative imaging modalities.

Total-body MR-imaging in oncology

Although MRI is an effective modality in oncology, state-of-the-art total-body MRI (TB-MRI) in the past was infeasible in the diagnostic work-up, due to the need for repeated examinations with repositioning and separate surface coils to cover all body parts. To overcome this limitation, either a moving table platform in combination with the body-coil or a special designed rolling table platform with one body phased-array coil have been implemented with promising results for both tumor staging and metastases screening. Since 2004, state-of-the-art TB-MR imaging with high spatial resolution has become feasible using a newly developed 1.5 Tesla TB-MRI system with multiple receiver channels. This review gives an overview based on the recent literature as well as our own experience concerning the possibilities, challenges, and limitations of TB-MRI in oncology, emphasizing both oncological staging and early tumor detection in asymptomatic subjects.

MRT zum Staging des Lungenkarzinoms

PURPOSE

Overview of magnetic resonance imaging (MRI) in staging of lung cancer.

MATERIAL AND METHODS

Currently available methods of imaging lung cancer, lymph node and distant metastases by MRI are explained. At present, MRI is mainly used in the detection of cerebral metastases and assessment of infiltration of the thoracic wall and of the mediastinum. The capabilities of T2-weighted single-shot TSE (HASTE) and T1-weighted 3D gradient echo techniques (VIBE) are demonstrated.

RESULTS

With the advent of new fast sequences like HASTE and VIBE the spatial resolution comes close to that of computed tomography but with an outstanding soft tissue contrast and without radiation exposure. The introduction of lymph node specific contrast media will improve sensitivity and specificity in N staging. Additionally, whole-body MRI is capable of detecting distant metastases, in particular in the organs at risk, i.e. brain, upper abdomen and musculoskeletal system.

CONCLUSION

MRI is gaining importance as part of a multimodal imaging approach for staging of lung cancer.

Whole-body MRI in the detection of bone marrow infiltration in patients with plasma cell neoplasms in comparison to the radiological skeletal survey

To compare the diagnostic value of whole-body MRI versus radiological skeletal survey (RSS) in staging patients with plasma cell neoplasms (PCN) and to evaluate the possible therapeutic impact of the replacement of RSS by whole-body MRI. Fifty-four patients with PCN [multiple myeloma (MM), n=47; monoclonal gammopathy of unknown significance (MGUS), n=7] were studied by whole-body MRI and RSS in a monocenter prospective analysis from August 2002 to May 2004. The MRIs were performed using a rolling table platform "AngioSURF" for unlimited field of view with a 1.5-T system (Magnetom Sonata/Maestro Class, Siemens Medical Solutions, Erlangen, Germany). A coronal STIR sequence (TR5500-4230/TE102-94/TI160) was used for imaging of the different body regions, including the head, neck, thorax, abdomen, pelvis and upper and lower extremities. The RSS consisted of eight different projections of the axial and appendicular skeleton. In 41/54 (74%) patients, the results of the whole-body MRI and RSS were concordant. In 11/54 (20%) patients, both imaging techniques were negative. Bone involvement was observed in 30/54 (55%) patients; however, whole-body MRI revealed this more extensively than the RSS in 27/30 (90%) patients with concordant positive imaging findings. In 3/30 (10%) patients, both imaging techniques demonstrated a similar extent of bone marrow infiltration. In 10/54 (19%) patients, the whole-body MRI was superior to RSS in detecting bone marrow infiltration, whereas the RSS was negative. In 3/54 (6%) patients, the RSS was proven to be false positive by the clinical course, whereas the whole-body MRI was truly negative. Whole-body MRI is a fast and highly effective method for staging PCN patients by the use of a rolling table platform. Moreover, it is more sensitive and specific than RSS and reveals bone marrow infiltration and extensive disease more reliably. Therefore, whole-body MRI should be performed as an additional method of exactly staging PCN patients and - with more data in the field - may even prove to be an alternate and more sensitive staging procedure than RSS in PCN patients.

Incidence and imaging characteristics of skeletal metastases detected by bone scintigraphy in lung cancer patients

Background/Aim. Detection of metastatic bone disease by skeletal scintigraphy is a classical application of nuclear medicine in cancer patients. Detection of bone metastases in patients with lung cancer is necessary for an appropriate treatment modality. The aim of this study was to report the frequency and imaging characteristics of bone metastases detected by bone scintigraphy (BS) using technetium-99m phosphonates in patients with lung cancer. Methods. We retrospectively analyzed a total of one hundred patients (78 males and 22 females), mean age of 63.3 years, with the diagnosis of lung cancer, who underwent BS during a three-year period (2003?2005). Scintiscans were classified as positive, negative and suspicious with regard to the presence of bone metastases. Results. The incidence of positive, negative and suspicious findings were 57%. 32% and 11%, respectively. Out of 57 patients with bone metastases, 51 had multiple asymmetric foci of increased tracer activity localized in the ribs, spine, extremities, pelvis, sternum, scapula and skull in 72%, 54%, 49%, 37%, 12%, 9% and 5% of scans, respectively. BS revealed solitary metastases in 6 of the patients. The lesions were located in the lower limbs in three patients and in the upper limbs, pelvis and sternum in the remaining three patients. Conclusion. Bone scintigraphy plays a significant role in staging and selecting of patients for curative lung surgery. Due to the fact that metastatic involvment of the extremities was frequently shown, our study suggests that systematic inclusion of the limbs in BS acquisition should be obligatory.