Staging des Mammakarzinoms Wertigkeit bildgebender Verfahren

In women with breast cancer, staging of the tumor plays an important role and often is considered to be the most prognostic and therapeutic factor. The most widely used staging system is based on the pathologic TNM classification. In recent years conservative therapies such as preoperative chemo- or radiotherapy are used more often with limited tissue evaluation resulting in insufficient or even inaccurate staging data. Tumor size as well as nodal involvement is decisive in selecting a treatment method and assessing the response. Thus, more accurate preoperative in vivo staging is necessary. This article therefore gives an overview of the different imaging modalities (mammography, ultrasonography, magnetic resonance imaging, and nuclear medicine) used for breast cancer staging. Furthermore, results of these methods are compared critically with the pathohistologic staging.     

Primary bone tumors of the lower extremities

The key to adequate and accurate evaluation, diagnosis, and treatment of bone tumors is an organized and integrated approach involving the surgeon, radiologist, and pathologist. The radiologist plays not only a valuable role in the diagnosis and preoperative staging of bone tumors but may also play a role in biopsy and treatment. Despite the wide variety of imaging modalities available today, radiographs remain the mainstay in the evaluation of osseous neoplasms. Advanced imaging is. however. very useful for staging purposes and for characterization of the internal characteristics of tumors and may aid significantly in limiting the differential diagnosis. Although a detailed discussion of all ofthe various bone tumors of the lower extremities is beyond the scope of this article, an attempt is made to provide a framework for a rational and comprehensive approach to these complicated but relatively uncommon lesions. Certain lesions with unique characteristics are discussed to facilitate the diagnostic process.     

Soft-tissue sarcomas of the extremities. Their assessment with magnetic resonance

MR imaging was performed on 38 patients with suspected malignant soft-tissue tumors of the extremities. MR diagnostic accuracy was compared with that of other methods. All patients underwent surgical control. In 7 cases MR imaging was employed to demonstrate the tumor response to antiblastic local perfusion. Lesion identification, extension, compartmental evaluation, bone and vascular involvement were the diagnostic parameters considered. In all cases MR imaging detected the lesion, correctly showing the intracompartmental (16 patients) or extracompartmental (22 patients) extension. In 2 out of 6 cases MR imaging did not demonstrate bone invasion, and in 1 case vascular involvement could not be assessed. MR diagnostic accuracy was superior to that of other techniques. Nonetheless, a diagnostic protocol was proposed for the local staging of malignant soft-tissue tumors of the extremities where some diagnostic limitations of MR imaging are taken into account--i.e., inconsistent evaluation of bone and vascular involvement. Plain X-rays and US are the imaging modalities of choice, whereas MR imaging is to be a second-choice diagnostic technique before biopsy. Thus, MR imaging replaces CT, while angiography is to be used in selected cases, where MR imaging is not diagnostic due to vascular involvement.     

MR imaging of cervical carcinoma: a practical staging approach.

Cervical carcinoma is the third most common gynecologic malignancy and is typically seen in younger women, often with serious consequences. The International Federation of Gynecology and Obstetrics (FIGO) staging system provides worldwide epidemiologic and treatment response statistics. However, there are significant inaccuracies in the FIGO staging system, and magnetic resonance (MR) imaging, although not included in that system, is now widely accepted as optimal for evaluation of important prognostic factors such as lesion volume and metastatic lymph node involvement that will help determine the treatment strategy. MR imaging examination obviates the use of invasive procedures such as cystoscopy and proctoscopy, especially when there is no evidence of local extension. Brachytherapy and external beam therapy are optimized with MR imaging evaluation of the shape and direction of lesion growth. In general, T2-weighted MR imaging more clearly delineates cervical carcinoma and is preferred for evaluation of the lymph nodes. Dynamic gadolinium-enhanced T1-weighted imaging may help identify smaller tumors, detect or confirm invasion of adjacent organs, and identify fistulous tracts. MR imaging staging, when available, is invaluable for identifying important prognostic factors and optimizing treatment strategies.     

Tumor-induced osteomalacia – Current imaging modalities and a systematic approach for tumor localization

Paraneoplastic syndromes are symptom complexes that cannot be readily explained by local or distant spread of the tumor. They can occur due to hormone production, autoimmunity or other biologically active products produced by the tumor, etc. Tumor induced osteomalacia is a rare paraneoplastic syndrome in which the manifestation is mainly musculoskeletal such as bone pain, fractures and muscle weakness as a consequence of elaboration of fibroblast growth factor 23 (FGF23) by the tumor.Most of these tumors are solitary and small and hence localization of these tumors is often challenging. This review summarizes the various anatomic imaging modalities such as plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) and nuclear medicine imaging techniques in the evaluation of these tumors.     

The clinical evaluation of bone tumors

Bone tumors are uncommon clinical entities that are often a source of diagnostic and therapeutic uncertainty. Evaluating these lesions starts with a patient history and physical examination Imaging then begins with radiographs, followed by advanced imaging modalities, such as magnetic resonance imaging, computed tomography, or bone scan. Biopsy can be performed to establish histologic diagnosis by either closed or open means. Treatment options range from observation to wide resection with reconstruction or amputation. Surveillance schedules vary depending on the type of tumor that is being treated. An algorithm for the evaluation, work-up, and diagnosis of bone tumors is presented.     

Perfusion computed tomography in renal cell carcinoma

Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma (RCC). While contrast enhanced computed tomography (CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT (pCT), goes down to the molecular level and provides new perspectives in imaging of RCC. pCT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using pCT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of pCT in staging and response assessment in patients with RCCs.     

Positron Emission Tomography in Diagnosis and Therapy Monitoring of Patients with Lymphoma

In contrast to conventional imaging modalities, positron emission tomography using fluorodeoxyglucose detects malignant tumors by their increased glucose metabolism. In patients with Hodgkin's disease or non-Hodgkin's lymphoma, FDG-PET imaging has been shown to sensitively identify enhanced tracer uptake in involved lymph nodes and infiltrated tissue. This brief review will summarize the currently available information on staging of lymphoma patients in comparison with other imaging modalities. In addition, FDG PET imaging has been suggested for differentiation of viable residual or recurrent tumor and scar after tumor therapy. One of the most promising applications of PET in the future will be the metabolic evaluation of early response to tumor therapy. It is hypothesized that changes in tumor metabolism occur before significant decrease of tumor mass. Early assessment of chemotherapy might help to avoid the toxicity of an ineffective therapy. In summary, the results concerning various clinical applications of PET imaging are encouraging for further prospective trials to document the advantage of PET in diagnosis and therapy of lymphoma patients as compared to conventional strategies.     

Técnicas avanzadas de resonancia magnética en patología tumoral de cabeza y cuello

Magnetic resonance imaging has become a fundamental tool for the evaluation of head and neck tumors. The anatomic details that magnetic resonance images provide are fundamental for diagnosing, characterizing, and staging both primary tumors and lymph node metastases.In addition to technical improvements in anatomic sequences, such as Dixon techniques to improve fat suppression, other sequences being developed, such as diffusion and perfusion, provide molecular, biological, and physiological information about the tumor and are yielding imaging biomarkers that can help in determining the tumor's biology at the time of diagnosis and in the follow-up of the disease. Magnetic resonance imaging also provides very useful information about the response to treatment.     

Imaging in bone sarcomas. The chemotherapist's point of view

The role of imaging in planning oncologic treatment and follow-up of patients with bone sarcomas is discussed in the present article. Tumor staging and radiographic assessment of response to chemotherapy in bone sarcomas may be of difficult interpretation. In particular, the use of the criterion of tumor shrinkage to measure response to chemotherapy is not always applicable in bone tumors where higher calcification rather than reduction in size is frequently observed. New techniques such as (18)F-FDG PET/CT, dynamic contrast-enhanced computed tomography or magnetic resonance are now available allowing a more accurate staging of patients and adding information for the evaluation of tumor response. Innovative approaches aiming to evaluate vascular and metabolic response rather than mono- or bi-dimensional changes may be more informative and require further investigations.     

Positron emission tomography for evaluation of colorectal carcinoma

Evaluation of patients with known or suspected recurrent colorectal carcinoma is now an accepted indication for FDG PET imaging. FDG PET does not replace imaging modalities such as CT for preoperative anatomic evaluation but is indicated as the initial test for diagnosis and staging of recurrence and for preoperative staging (N and M) of known recurrence that is considered to be resectable. FDG PET imaging is valuable for differentiation of posttreatment changes from recurrent tumor, differentiation of benign from malignant lesions (indeterminate lymph nodes, hepatic and pulmonary lesions), and evaluation of patients with rising tumor markers in the absence of a known source. Addition of FDG PET to the evaluation of these patients reduces overall treatment costs by accurately identifying patients who will and will not benefit from surgical procedures. Although initial staging at the time of diagnosis is often performed during colectomy, FDG PET imaging is recommended for a subgroup of patients at high risk (with elevated CEA levels) and normal CT and for whom surgery can be avoided if FDG PET shows metastases. Screening for recurrence in patients at high risk has also been advocated. FDG PET imaging seems promising for monitoring therapy, but larger studies are necessary.     

Radiological imaging for the diagnosis of bone metastases.

Primary neoplasms of the skeleton are rare, but metastatic involvement is, unfortunately, a common occurrence. This is particularly true for certain primary tumors. Skeletal metastases are clinically significant because of associated symptoms, complications such as pathological fracture and their profound significance for staging, treatment and prognosis. Detection of bone metastases is, thus, an important part of treatment planning. The frequency with which metastases are detected varies considerably with the type of primary tumor and with the methodology utilized for detection. Four main modalities are utilized clinically: plain film radiography, CT scan, nuclear imaging and magnetic resonance imaging. In this discussion, we will review literature on the radiology of skeletal metastases with respect to lesion detection, assessment of response to treatment and possible therapeutic implications. The bulk of the discussion will focus on MRI and nuclear studies since most of the recent advances have been made in these areas.     

Diagnosis and therapy of carcinoid tumors—current state of the art and future directions

Carcinoid tumors account for less than 1% of all malignancies and the majority arise in the gastrointestinal system. These tumors are slow growing compared with adenocarcinomas and they differ from the other neuroendocrine malignancies by their protean clinical presentation. Carcinoid tumors were previously considered indolent, but they can manifest malignant characteristics with metastatic spread which often results in a poor prognosis.Although there have been advances in diagnostic and treatment modalities, carcinoid tumors are still often diagnosed late, often when the tumor has metastasized and patients develop carcinoid syndrome. Diagnosis, prognosis and treatment options are based on biochemical markers and imaging investigations. High concentration of urinary 5-HIAA, elevated plasma serotonin and chromogranin A levels help to establish the initial diagnosis of carcinoid tumors. In addition to the CT and MRI, molecular imaging modalities such as OctreoScan, MIBG imaging and more recently PET imaging are vital in detection of primary malignancy and metastatic involvement.Surgery is the mainstay of treatment of nonmetastatic carcinoid tumors. Cytotoxic chemotherapy is not beneficial due to the chemoresistant nature of these tumors. Because carcinoid tumors express somatostatin receptors, somatostatin analogues, which inhibit the release of serotonin and other neuroendocrine peptides, are often used, but their use is limited to symptom control. Treatment using high doses of radionuclides such as radiolabeled somatostatin analogues and MIBG is a more recent option which offers a definite advantage in management. In this article, we review typical features of the carcinoid tumors, examine contemporary methods of detecting and assessing carcinoid tumors and discuss the role of various diagnostic and therapeutic options.     

Staging muskuloskeletaler Tumoren in der Bildgebung

The staging of primary malignant bone and soft tissue tumors requires adherence to a unified staging system. The staging system of the American Joint Commission for Cancer, the Enneking system, and the Hajdu system are described in respect of the radiologic staging criteria. Plain film radiography can estimate the biological aggressiveness of a bone tumor and in many cases narrow the differential diagnosis. Computed tomography is most sensitive in depicting cortical erosions and calcified periosteal reactions as well as in screening for distant metastasis. Angiography is mainly employed for vascular tumors and for the monitoring of interventional procedures such as tumor embolization. For both bone and soft tissue tumors, magnetic resonance tomography is the method of choice for the staging of intra- and extramedullary tumor extension, for the differentiation of neighboring compartments, and in the detection of invasion of the regional neurovascular bundle. After administration of contrast agents, the mode of enhancement gives further information on the nature of the tumor. With consistent application of the staging criteria in preoperative imaging, limb-saving therapy can be employed more often and the prognosis of the disease can be improved.     

Morphologic and functional imaging of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive tumor that arises from the pleura and frequently extends to adjacent structures. MPM cells produce and respond to many angiogenic factors, such as vascular endothelial growth factor (VEGF). VEGF expression in MPM is correlated with microvascular density, which is associated with poor survival. CT has been widely used as the primary imaging modality for the clinical evaluation of MPM. Major findings include nodular pleural thickening, unilateral pleural effusion, and tumor invasion of adjacent structures. CT tends to underestimate early chest wall invasion and peritoneal involvement and has well-known limitations in the evaluation of lymph node metastases. Perfusion CT can evaluate the microvasculature of tumors, while its disadvantages, such as high radiation exposure or side effects from iodinated contrast, limit its use in both research and clinical settings. MRI can provide additional information to CT. Because of its excellent contrast resolution, MRI is superior to CT, both in the differentiation of malignant from benign pleural disease, and in the assessment of chest wall and diaphragmatic involvement. Perfusion MRI is the most promising technique for the assessment of the tumor microvasculature. In MPM, therapeutic effects of chemotherapy can be monitored with perfusion MRI. It has been shown that FDG-PET is useful for the differentiation of benign from malignant lesions, for staging and monitoring metabolic response to therapy against MPM, and that it has prognostic value. An initial report on PET/CT imaging of MPM has shown increased accuracy of overall staging, improving the assessment of tumor resectability. PET/CT seems to be superior to other imaging modalities in detecting more extensive disease involvement, and identifying unsuspected occult distant metastases.     

Fluorine-18-deoxyglucose-positron emission tomography imaging with magnetic resonance and computed tomographic correlation in the evaluation of bone and soft-tissue sarcomas: a pictorial essay

Positron emission tomography (PET) imaging has a growing role as an imaging modality to be used in conjunction with magnetic resonance and computed tomographic imaging in the detection, staging, and management of many sarcomas and carcinomas. Since PET is a relatively new modality and the incidence of sarcomas is low, it has not yet been approved for use in all bone and soft-tissue sarcomas. The purpose of this article is to pictorially evaluate soft-tissue and bone sarcomas, including malignant peripheral nerve sheath tumor, synovial sarcoma, osteosarcoma, liposarcoma, rhabdomyosarcoma, malignant fibrous histiocytoma, fibrosarcoma, and myxofibrosarcoma. This pictorial essay illustrates and describes these tumors in various stages of disease progression vis-à-vis fluorine-18-deoxyglucose-PET imaging with computed tomographic and magnetic resonance correlation. Various stages of disease progression will be discussed including initial diagnosis, treatment response, and metastatic involvement.     

Rektumkarzinom – Lokales Staging und Bildgebung unter neoadjuvanter Therapie

CLINICAL/METHODICAL ISSUE: Rectal cancer restaging after neoadjuvant therapy is based on two principles: an anatomic definition of the tumor allowing surgical planning and prognostic stage grouping. STANDARD RADIOLOGICAL METHODS: Emerging data suggest that reassessment using a combination of different imaging modalities may help to provide valuable prognostic information before definitive surgery. METHODICAL INNOVATIONS: Perfusion computed tomography (CT) may provide special information regarding tumor vascularity. PERFORMANCE: Evaluation of therapy response, especially of the circumferential resection margin (CRM) is necessary for surgical planning. ACHIEVEMENTS: For local staging high-resolution and diffusion-weighted magnetic resonance imaging has proven to be of high diagnostic accuracy. PRACTICAL RECOMMENDATIONS: The M status should be assessed using multidetector computed tomography (MDCT) according to response evaluation criteria in solid tumors (RECIST) while lymph node evaluation requires either magnetic resonance imaging or positron emission tomography/computed tomography scanning.     

PET and PET-CT for evaluation of colorectal carcinoma

The evaluation of patients with known or suspected recurrent colorectal carcinoma is now an accepted indication for positron emission tomography using (18)F-fluorodeoxyglucose (FDG-PET) imaging. FDG-PET does not replace imaging modalities such as computed tomography (CT) for preoperative anatomic evaluation but is indicated as the initial test for diagnosis and staging of recurrence and for preoperative staging (N and M) of known recurrence that is considered to be resectable. FDG-PET imaging is valuable for the differentiation of posttreatment changes from recurrent tumor, differentiation of benign from malignant lesions (indeterminate lymph nodes, hepatic and pulmonary lesions), and the evaluation of patients with rising tumor markers in the absence of a known source. The addition of FDG-PET to the evaluation of these patients reduces overall treatment costs by accurately identifying patients who will and will not benefit from surgical procedures. Although initial staging at the time of diagnosis is often performed during colectomy, FDG-PET imaging is recommended for a subgroup of patients at high risk (with elevated CEA levels) and normal CT and for whom surgery can be avoided if FDG-PET shows metastases. Screening for recurrence in patients at high risk has also been advocated. FDG-PET imaging seems promising for monitoring patient response to therapy but larger studies are necessary. The diagnostic implications of integrated PET-CT imaging include improved detection of lesions on both the CT and FDG-PET images, better differentiation of physiologic from pathologic foci of metabolism, and better localization of the pathologic foci. This new powerful technology provides more accurate interpretation of both CT and FDG-PET images and therefore more optimal patient care. PET-CT fusion images affect the clinical management by guiding further procedures (biopsy, surgery, radiation therapy), excluding the need for additional procedures, and changing both inter- and intramodality therapy.     

Imaging of uterine cancer

Although surgical staging is the primary method of assessing prognostic factors in endometrial cancer, cross-sectional imaging may help in treatment planning by providing information about factors such as the depth of myometrial invasion, cervical involvement, and nodal status. The pretreatment evaluation of cervical cancer traditionally has consisted of clinical evaluation, laboratory tests, and conventional radiographic studies, but more advanced imaging methods allow additional insights into the morphologic and metabolic features of cervical cancer. This article reviews the applications of modern imaging modalities in the assessment of endometrial cancer and cervical cancer and their impact on treatment planning and posttreatment follow-up.     

Positron emission tomography as a diagnostic tool in oncology

Early diagnosis in oncology is important for treatment by surgical intervention, which generally has the highest curative potential. For higher stages of disease involvement, initiation of rapid treatment is indicated to provide the patient with the optimal therapy regimen. Although this may not improve the prognosis, it will maintain the quality of life. Anatomic imaging modalities, such as CT, MR imaging, and US, are clinically important high-resolution imaging techniques that are well suited to reveal structural abnormalities. However, the differentiation of lesions as being benign or malignant is still problematic. Metabolic imaging modalities in nuclear medicine (NM), i. e., single photon emission computed tomography (SPECT) and positron emission tomography (PET), can reveal biochemical parameters of the lesions such as glucose, oxygen, or amino acid metabolism, or measure the receptor density status. These parameters may allow a completely new clinical perspective in the management and understanding of diseases such as cancer. Although PET has been around since the early 1960 s, it has only recently emerged as a powerful diagnostic tool in oncology. Society has great difficulty accepting this clinical imaging modality because of its high cost and complexity. Current applications of PET in oncology have been in characterizing lesions, differentiating recurrent disease from treatment effects, staging tumors, evaluating the extent of disease, and therapy monitoring. Here, the role of PET in diagnosis, staging, and restaging of cancer is reviewed and compared with the other tumor imaging modalities. We cover articles published in the past 3 years. We utilize the typical radiology format, in which the contribution in each body area is reviewed (topographic orientation), instead of the more organ-based approach used in internal medicine. Received 1 August 1998; Accepted 23 January 1998