Calvarial lesions: a radiological approach to diagnosis.

Calvarial lesions are frequently identified in radiological studies. A wide variety of neoplasms and non-neoplastic lesions can involve the calvarium, and their imaging appearances vary according to their pathologic features. These lesions are usually asymptomatic but may manifest as a lump with or without associated pain. Clinical information, including the age of patient, is an important factor in the diagnostic process. In this paper, we illustrate the value of cross-sectional imaging techniques by computed tomography (CT) and magnetic resonance imaging (MRI) in evaluating these lesions. We also review the literature and discuss the specific imaging characteristics of the most common calvarial lesions in order to provide information that can guide radiological diagnosis or limit differential diagnosis.

Two cases with fatal outcome following total lung irradiation for metastatic bone sarcoma.

We report a single institution experience with total lung irradiation in 53 metastatic bone sarcoma patients in the context of two young female patients who died from treatment-induced pulmonary toxicity. A radiation dose of 19.5 Gy in 1.5 Gy daily fractions was given as two opposing fields with a conventional technique. Both patients succumbed within 3 months following radiotherapy. One patient had osteosarcoma whereas the other advanced Ewing's sarcoma; both with widespread metastases to the lungs at primary diagnosis. In retrospect, most likely high dose methotrexate lung toxicity observed in the osteosarcoma patient, and the GI-toxicity following pelvic radiotherapy in Ewing's case, both observed during the initial phase of their multimodal treatment, might indicate an increased individual radiosensitivity. In view of this, a review of our experience in 53 bone sarcoma patients (19 with Ewing's sarcoma and 34 with osteosarcoma) treated at our institution was conducted. We have not previously experienced significant toxicity following total lung irradiation. Among these, 42% (8/19) with Ewing's sarcoma and 9% (3/34) with osteosarcoma are long-term survivors and without clinically significant lung toxicity.

[Magnetic resonance tomography in oncology diagnostics]. / Magnetisk resonanstomografi innenfor onkologisk diagnostikk.

MR is well suited for imaging in patients with malignant disease. It is the most sensitive and most specific method in the detection of skeletal metastases. It clearly demonstrates the extent of primary bone tumours and also reveals skip metastases and invasion into neighbouring joints, hence it is an important procedure when surgery of a bone tumour is planned. In case of a soft tissue tumour, MR is the preferable imaging modality because it demonstrates the anatomy and reveals the different tissue constituents. MR is the best method to show tumour manifestations in the central nervous system, and it supplements cerebrospinal fluid examination in the detection of meningeal metastasis. MR is the method of choice if there is a cord compression. MR imaging is important in gynecologic oncology. Cost savings have been reported due to reduced use of other diagnostic tests and expensive surgical procedures. New and faster techniques allow examination of the total body in less than 45 minutes. We expect that MR imaging will be increasingly used in the future in patients with malignant disease.

Dichotic memory: paradoxical effect of removing a left frontal gyrus: a case study.

A 27-year-old right-handed woman was operated with resection of an epileptogenic lesion, a nonmalignant tumor, in the left frontal lobe. The surrounding cortical and subcortical tissue in the tumor-containing gyrus was also resected. Care was taken during the operation not to interfere with motor or language related cortical areas. Pre- and postoperatively, she was tested with a dichotic memory test. In the preoperative test, she showed a marked Left Ear Advantage. In the corresponding tests on the second and fourth postoperative days and at follow-up, her performance had changed to a Right Ear Advantage. A possible explanation of this result is that neighboring cortical areas involved in hemispheric specialization for lateralized, verbal cognitive functions are suppressed by a focal epiletogeneic activity caused by the tumor. The subsequent removal of this influence allowed these cortical areas to function normally.

Assessment of tumor oxygenation in human cervical carcinoma by use of dynamic Gd-DTPA-enhanced MR imaging.

Increased knowledge of the physiological basis behind the signal enhancement in tumors during dynamic contrast-enhanced magnetic resonance (MR) imaging may be useful in development of predictive assays based on this technique. In the present work, the relative signal intensity (RSI) increase in gadopentetate dimeglumine (Gd-DTPA)-enhanced MR images of patients with cervical carcinoma was related to tumor perfusion, vascular density, cell density, and oxygen tension (pO(2)). The patients were subjected to MR imaging before the start of treatment (N = 12) and after two weeks of radiotherapy (N = 8). Perfusion was determined from the kinetics of contrast agent in tumors and arteries, vascular density and cell density were determined from tumor biopsies, and pO(2) was determined by polarographic needle electrodes. The maximal RSI was correlated to perfusion (P = 0.002) and cell density (P = 0.004), but was not related to vascular density. There was also a correlation between pO(2) and perfusion (P < 0.001). Moreover, pO(2) tended to be correlated to cell density (P = 0.1), but was not related to vascular density. There was a significant correlation between RSI and pO(2), regardless of whether the median pO(2) (P < 0.001) or the fraction of pO(2) readings below 2.5 mmHg (P < 0.001), 5 mmHg (P < 0.0001), or 10 mmHg (P < 0.001) was considered. Our results suggest that the Gd-DTPA-induced signal enhancement in MR images of cervical tumors is influenced by both perfusion and cell density. These parameters are also of major importance for tumor oxygenation, leading to a correlation between signal enhancement and oxygenation. Dynamic contrast-enhanced MR imaging may therefore possibly be useful in prediction of treatment outcome.

Intra- and intertumor heterogeneity in blood perfusion of human cervical cancer before treatment and after radiotherapy.

Knowledge of the intratumor heterogeneity in blood perfusion may lead to increased understanding of tumor response to treatment. In the present work, absolute perfusion values, in units of ml/g.min, were determined in 20 tumor subregions of patients with cervical cancer before treatment (n = 12) and after 2 weeks of radiotherapy (n = 8), by using a method based on contrast-enhanced magnetic resonance imaging. The aims were to evaluate the intratumor heterogeneity in perfusion in relation to the intertumor heterogeneity and to search for changes in the heterogeneities during the early phase of therapy. The intra- and intertumor heterogeneity in perfusion were estimated from components of one-way analyses of variance. The mean perfusion differed significantly among the patients before treatment, ranging from 0.044 to 0.12 ml/g x min. Large differences in perfusion were also observed within individual tumors. The heterogeneity was largest in the best perfused tumors, perfusion values ranging, e.g., from 0.055 to 0.29 ml/g x min were observed. The intratumor heterogeneity was similar to the intertumor heterogeneity. The mean perfusion generally increased or tended to increase during radiotherapy, ranging from 0.064 ml/g x min to 0.13 ml/g x min after 2 weeks of treatment. There was a tendency of increased intratumor heterogeneity in perfusion after therapy, consistent with the higher mean value; a difference in perfusion of more than a factor of 10 was seen within some tumors. These results suggest that cervix tumors contain a significant amount of poorly perfused subregions with high treatment resistance. Moreover, the perfusion and perfusion heterogeneity may increase during the early phase of radiotherapy and influence tumor response.