Tumour inhomogeneities on magnetic resonance imaging, a new factor with prognostic information in non-Hodgkin's lymphomas.

The prognostic importance of inhomogeneities on magnetic resonance imaging (MRI) in non-Hodgkin lymphomas (NHL) was evaluated. Forty-six consecutive patients with high-grade NHL were examined and, for comparison purposes, 13 patients with low-grade NHL. The degree of inhomogeneity was measured with a quantitative method (IH8) and a subjective evaluation was also performed. Patients with localized disease (stage I), who had all been treated with radiotherapy, had an excellent prognosis, which was independent of the degree of tumour inhomogeneity. In generalized NHL (stages II-IV) treated with chemotherapy, IH8 provided prognostic information in high-grade NHL. Patients with pronounced tumour inhomogeneity, in particular, had a very poor prognosis. The prognostic impact was also seen if the analyses were performed with high-grade and low-grade NHLs grouped together. The inhomogeneities may indicate a mechanism related to treatment failure after chemotherapy, but not after fractionated radiotherapy.

Non-Hodgkin lymphoma: predicting prognostic grade with MR imaging.

Fifty patients with non-Hodgkin lymphoma (NHL) were examined with magnetic resonance (MR) imaging in order to analyze whether it is possible to distinguish in vivo between the two major prognostic groups, low-grade NHL and high-grade NHL. Most high-grade NHL nodes (15 of 24 [63%]) had an inhomogeneous appearance at MR imaging, in contrast to low-grade NHL nodes, which were homogeneous in almost all patients (18 of 20 [90%]) (P less than .001). A homogeneous image was also found in six patients who had previously received a diagnosis of low-grade NHL; at the time of examination their lesions had transformed into high-grade NHL. Necrosis, detectable in the histopathologic sections, was usually (five of six cases) associated with an inhomogeneous image. However, the images were also inhomogeneous [corrected] in 12 of 44 cases (27%) in which there were no signs of necrosis in the histopathologic sections. Patients with high-grade NHL and a homogeneous signal intensity pattern tended to have a better survival rate than those with an inhomogeneous pattern.

Residual mediastinal masses in Hodgkin disease: prediction of size with MR imaging.

Eighteen patients with mediastinal involvement of Hodgkin disease were examined with magnetic resonance (MR) imaging before and during therapy to find out if size of residual masses could be predicted from the MR characteristics of the tumor at diagnosis. After the first treatment, a significant decrease in T2 values and signal intensity ratios of tumor to fat and tumor to muscle was found in all patients. There was no significant change in T1 values. The relative decrease in tumor size correlated well with signal intensity ratios and poorly with T2 values of the original tumor. No correlation with T1 values was found. The authors conclude that size of the residual mass can be predicted from the initial size of the tumor and the signal intensity ratios at diagnosis. Since the degree of low signal intensity in the tumor before treatment probably reflects the amount of fibrotic tissue, these results support the hypothesis that residual masses after treatment are remnants of the fibrotic stroma of the original tumor.

CT in malignancy grading and prognostic prediction of non-Hodgkin's lymphoma.

PURPOSE: The presence of tumor inhomogeneities in MR images of non-Hodgkin's lymphoma (NHL) provides information about malignancy grade and prognosis. The aim of this study was to determine whether CT images are also informative in these respects. MATERIAL AND METHODS: Sixty-three CT examinations in patients with NHL (32 high-grade and 31 low-grade tumors) were reviewed retrospectively by two senior radiologists. The tumor patterns were classified subjectively as homogeneous, slightly inhomogeneous or severely inhomogeneous and their relations to malignancy grade, clinical characteristics and prognosis were determined. RESULTS: Sixteen out of 17 patients with a severely inhomogeneous tumor pattern had high-grade NHL tumors while 21 out of 29 patients with a homogeneous tumor appearance had low-grade NHL tumors. Among chemotherapy-treated patients, those with the highest degree of inhomogeneity had a significantly worse prognosis (9 out of 11 patients died). This relationship was not found in patients treated with radiotherapy. CONCLUSION: A severely inhomogeneous tumor pattern on CT images was found to be associated with a high malignancy grade in NHL. This CT pattern was also compatible with a poor prognosis in patients treated with chemotherapy.