Whole-body MRI for initial staging of paediatric lymphoma: prospective comparison to an FDG-PET/CT-based reference standard.

OBJECTIVE: To compare whole-body MRI, including diffusion-weighted imaging (whole-body MRI-DWI), with FDG-PET/CT for staging newly diagnosed paediatric lymphoma. METHODS: A total of 36 children with newly diagnosed lymphoma prospectively underwent both whole-body MRI-DWI and FDG-PET/CT. Whole-body MRI-DWI was successfully performed in 33 patients (mean age 13.9 years). Whole-body MRI-DWI was independently evaluated by two blinded observers. After consensus reading, an unblinded expert panel evaluated the discrepant findings between whole-body MRI-DWI and FDG-PET/CT and used bone marrow biopsy, other imaging data and clinical information to derive an FDG-PET/CT-based reference standard. RESULTS: Interobserver agreement of whole-body MRI-DWI was good [all nodal sites together (κ = 0.79); all extranodal sites together (κ = 0.69)]. There was very good agreement between the consensus whole-body MRI-DWI- and FDG-PET/CT-based reference standard for nodal (κ = 0.91) and extranodal (κ = 0.94) staging. The sensitivity and specificity of consensus whole-body MRI-DWI were 93 % and 98 % for nodal staging and 89 % and 100 % for extranodal staging, respectively. Following removal of MRI reader errors, the disease stage according to whole-body MRI-DWI agreed with the reference standard in 28 of 33 patients. CONCLUSIONS: Our results indicate that whole-body MRI-DWI is feasible for staging paediatric lymphoma and could potentially serve as a good radiation-free alternative to FDG-PET/CT. KEYPOINTS: • Accurate staging is important for treatment planning and assessing prognosis • Whole-body MRI-DWI could be a good radiation-free alternative to FDG-PET/CT • Interobserver agreement of whole-body MRI-DWI is good • Agreement between whole-body MRI and the FDG-PET/CT reference standard is good • Most discrepancies were caused by suboptimal accuracy of size measurements on MRI.

Whole-body MRI vs. CT for staging lymphoma: patient experience.

OBJECTIVE: To assess and compare patient experience of whole-body magnetic resonance imaging (MRI) to that of computed tomography (CT) for staging newly diagnosed lymphoma. MATERIALS AND METHODS: A total of 36 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI and CT for staging purposes. Patients were asked to fill in a short questionnaire with regard to the burden and experience of the examination on a Likert scale (range 1-4). Wilcoxon signed rank tests were used to determine statistically significant differences in patient (dis)comfort between the two examinations. RESULTS: Patients reported to be significantly (P=0.007) less worried before undergoing whole-body MRI compared to CT. Patients also experienced whole-body MRI as significantly (P=0.010) less unpleasant and felt significantly (P=0.003) better shortly after the scan. The necessary preparations before CT scanning (i.e. insertion of intravenous line, drinking of contrast fluid), which are not required for whole-body MRI, were reported to be a considerable burden. CONCLUSION: In this study in patients with newly diagnosed lymphoma, whole-body MRI was experienced as a more patient-friendly technique than CT.

Whole-body MRI, including diffusion-weighted imaging, for staging lymphoma: comparison with CT in a prospective multicenter study.

PURPOSE: To compare whole-body magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), to computed tomography (CT) for staging newly diagnosed lymphoma. MATERIALS AND METHODS: In all, 108 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI (T1-weighted and T2-weighted short inversion time inversion recovery [n = 108], and DWI [n = 104]) and CT. Ann Arbor stages were assigned according to whole-body MRI and CT findings. Staging disagreements were resolved using bone marrow biopsy, FDG-PET, and follow-up studies. The results were descriptively analyzed. RESULTS: Staging results of whole-body MRI without DWI were equal to those of CT in 66.6%, higher in 24.1%, and lower in 9.3%, with correct/incorrect/unresolved higher staging and incorrect/unresolved lower staging relative to CT in 15/7/4 and 9/1 patient(s), respectively. Staging results of whole-body MRI with DWI were equal to those of CT in 65.4%, higher in 27.9%, and lower in 6.7%, with correct/incorrect/unresolved higher staging and incorrect/unresolved lower staging relative to CT in 18/6/5 and 6/1 patient(s), respectively. CONCLUSION: The results of this study suggest that whole-body MRI staging equals CT staging in the majority of patients with newly diagnosed lymphoma. No advantage of additional DWI was demonstrated. Whole-body MRI can be a good alternative to CT if radiation exposure should be avoided.

Radioembolization for treatment of salvage patients with colorectal cancer liver metastases: a systematic review.

UNLABELLED: Currently, there is no consensus on the use of (90)Y radioembolization for salvage patients with colorectal cancer liver metastases. The purpose of this study was to provide a comprehensive overview of the available data on tumor response and survival after (90)Y radioembolization for this group of patients. METHODS: A systematic literature search was conducted in PubMed (Medline), Excerpta Medica (EMBASE), and the Cochrane Library (September 2012) with synonyms for "radioembolization" and "colorectal cancer liver metastases." Results were described separately for patient cohorts treated with (90)Y radioembolization as monotherapy and with (90)Y radioembolization in combination with chemotherapy. RESULTS: The search yielded 13 relevant articles for systematic review on (90)Y radioembolization as monotherapy and 13 relevant articles on (90)Y radioembolization combined with chemotherapy. Disease control rates (i.e., complete response, partial response, and stable disease) ranged from 29% to 90% for (90)Y radioembolization as monotherapy and from 59% to 100% for (90)Y radioembolization combined with chemotherapy. Heterogeneity in the data prohibited pooling of response rates. Survival proportions at 12 mo ranged from 37% to 59% for (90)Y radioembolization as monotherapy and from 43% to 74% for (90)Y radioembolization combined with chemotherapy. CONCLUSION: In the studies included in this systematic review, approximately 50% of salvage patients with colorectal cancer liver metastases survive more than 12 mo after treatment with (90)Y radioembolization, either as monotherapy or in combination with chemotherapy. Heterogeneity between studies has unfortunately prohibited pooling of data. Future research will discern the precise role of (90)Y radioembolization in general clinical practice in comparison with chemotherapy.

Whole-body MRI for the detection of bone marrow involvement in lymphoma: prospective study in 116 patients and comparison with FDG-PET.

OBJECTIVE: To assess and compare the value of whole-body MRI with FDG-PET for detecting bone marrow involvement in lymphoma. METHODS: A total of 116 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI and blind bone marrow biopsy (BMB) of the posterior iliac crest. Of 116 patients, 80 also underwent FDG-PET. Patient-based sensitivities of whole-body MRI for detecting bone marrow involvement were calculated using BMB as reference standard and compared with FDG-PET in aggressive and indolent lymphomas separately. RESULTS: Sensitivity of whole-body MRI in all lymphomas was 45.5 % [95 % confidence interval (CI): 29.8-62.0 %]. Sensitivity of whole-body MRI in aggressive lymphoma [88.9 % (95 % CI: 54.3-100 %)] was significantly higher (P = 0.0029) than that in indolent lymphoma [23.5 % (95 % CI: 9.1-47.8 %)]. Sensitivity of FDG-PET in aggressive lymphoma [83.3 % (95 % CI: 41.8-98.9 %)] was also significantly higher (P = 0.026) than that in indolent lymphoma [12.5 % (95 % CI: 0-49.2 %)]. There were no significant differences in sensitivity between whole-body MRI and FDG-PET (P = 1.00) CONCLUSION: Sensitivity of whole-body MRI for detecting lymphomatous bone marrow involvement is too low to (partially) replace BMB. Sensitivity of whole-body MRI is significantly higher in aggressive lymphoma than in indolent lymphoma and is equal to FDG-PET in both entities. KEY POINTS: • Bone marrow involvement in lymphoma has prognostic and therapeutic implications. • Blind bone marrow biopsy (BMB) is standard for bone marrow assessment. • Neither whole-body MRI nor FDG-PET can yet replace BMB. • Both techniques have higher sensitivity in aggressive than in indolent lymphoma. • Both imaging techniques are complementary to BMB.

MRI for staging lymphoma: whole-body or less?

PURPOSE: To assess whether whole-body MRI detects more clinically relevant lesions (i.e., leading to a change in Ann Arbor stage) than an MRI protocol that only includes the head/neck and trunk (i.e., from cranial vertex to groin, excluding the arms) in patients with lymphoma. MATERIALS AND METHODS: One hundred consecutive patients with newly diagnosed lymphoma prospectively underwent T1-weighted and T2-weighted short inversion time inversion recovery whole-body MRI. The number of lymphomatous sites at MRI with a field of view (FOV) limited to the head/neck and trunk, and the additional number of lymphomatous sites at whole-body MRI and their influence on Ann Arbor stage were determined. RESULTS: At MRI with a FOV limited to the head/neck and trunk, 507 sites were classified as lymphomatous. At whole-body MRI, 7 additional sites outside the head/neck and trunk in 7 patients (7.0%; 95% confidence interval: 3.4-13.8%) were classified as lymphomatous, but Ann Arbor stage never changed. CONCLUSION: Whole-body MRI did not detect any clinically relevant lesions outside the FOV of an MRI protocol that only includes the head/neck and trunk. Therefore, it may be sufficient to only include the head/neck and trunk when using MRI for staging lymphoma.

Magnetic resonance imaging of malignant lymphoma.

Computed tomography (CT), (18)F-fluorodeoxyglucose (FDG)-PET and the hybrid FDG-PET/CT are the most commonly used diagnostic tools for the initial staging and treatment response assessment of malignant lymphomas. MRI techniques such as whole-body MRI and diffusion-weighted imaging may be good radiation-free alternatives to FDG-PET/CT, which may be particularly relevant for children. Diffusion-weighted imaging is characterized by high sensitivity for the detection of lesions and allows quantitative assessment of diffusion that may aid in the evaluation of malignant lymphomas. This article will review the value of these emerging MRI techniques for the staging and response assessment of malignant lymphoma. Furthermore, we will discuss some additional imaging techniques that are the subject of ongoing research and may have potential for future clinical application.

ADC measurements in the evaluation of lymph nodes in patients with non-Hodgkin lymphoma: feasibility study.

OBJECT: To determine whether apparent diffusion coefficient (ADC) measurements allow discrimination of normal lymph nodes from lymphomatous lymph nodes, and indolent lymphomas from aggressive lymphomas in patients with non-Hodgkin lymphoma (NHL). MATERIALS AND METHODS: Eighteen healthy volunteers and thirty-two patients with newly diagnosed NHL (indolent: n = 16; aggressive: n = 16) underwent diffusion-weighted imaging. ADCs of normal lymph nodes were compared to those of lymphomatous lymph nodes, and ADCs of indolent lymphomas were compared to those of aggressive lymphomas. Receiver operating characteristic (ROC) analysis was performed when ADCs were significantly different between two of the aforementioned groups. RESULTS: ADCs (in 10(-3) mm(2)/s) of lymphomatous lymph nodes (0.70 ± 0.22) were significantly lower (P < 0.0001) than those of normal lymph nodes (1.00 ± 0.15). Area under the ROC curve was 0.865. Sensitivity and specificity were 78.1 and 100% when using an optimal cutoff ADC value of 0.80. On the other hand, ADCs of indolent lymphomas (0.67 ± 0.21) were not significantly different (P = 0.2997) from those of aggressive lymphomas (0.74 ± 0.23). CONCLUSION: ADC measurements show promise as a highly specific tool for the discrimination of normal lymph nodes from lymphomatous lymph nodes, but appear to be of no utility in differentiating indolent from aggressive lymphomas.

Whole-body diffusion-weighted imaging for staging malignant lymphoma in children.

CT is currently the mainstay in staging malignant lymphoma in children, but the risk of second neoplasms due to ionizing radiation associated with CT is not negligible. Whole-body MRI techniques and whole-body diffusion-weighted imaging (DWI) in particular, may be a good radiation-free alternative to CT. DWI is characterized by high sensitivity for the detection of lesions and allows quantitative assessment of diffusion that may aid in the evaluation of malignant lymphomas. This article will review whole-body MRI techniques for staging malignant lymphoma with emphasis on whole-body DWI. Furthermore, future considerations and challenges in whole-body DWI will be discussed.