Whole-body MRI evaluation of tumor burden in the neurofibromatosis tumor suppressor syndromes

• Published in: Journal of clinical oncology Vol. 27; no. 15_suppl; p. 2074
• Main Authors: Plotkin, S. R., Singh, M., Cai, W., O'Donnell, C., Esparza, S., Smith, M. J., Harris, G. J., Muzikansky, A., Bredella, M. A., Kassarjian, A.
• Format: Journal Article
• Language: English
• Published: 20.05.2009
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2009.27.15_suppl.2074

Abstract only 2074 Background: Neurofibromatosis 1 (NF1), NF2, and schwannomatosis are a group of related genetic disorders in which affected individuals share the predisposition to develop multiple neurofibromas and schwannomas. The prevalence of internal tumors is not known because current estimates are based on regional MRI scans that may not detect occult tumors. A rapid and sensitive method to detect internal tumors is highly desirable since they can cause neurologic dysfunction, compress vital structures, or transform into malignant tumors. Whole-body MRI (WBMRI) is an imaging technique by which the entire body can be imaged in a relatively short time without the use of ionizing radiation. Methods: We performed WBMRI in subjects with NF1, NF2, or schwannomatosis as part of an IRB-approved research study. Each subject was imaged from head to ankles in the supine position using a 1.5 Tesla magnet, integrated body coil, and no intravenous contrast. Using five acquisitions, the entire body was imaged using a fat suppressed fluid sensitive STIR sequence. The images were then fused into a single whole body DICOM image. The number and type of tumors (discrete vs. plexiform) were identified by a board-certified radiologist and tumor volume was calculated using semi-automated analysis. Results: A total of 100 subjects were imaged (NF1–50; NF2–25, schwannomatosis-25). Sixty-one percent of subjects had ≥1 internal tumor. The median number of tumors in affected individuals was 5 (range, 1 to 63 tumors). Overall, the legs harbored the greatest number of tumors (33%), followed by the pelvis (18%), thorax (15%), abdomen (12%), arms (10%), and head/neck (7%). Only 40% of internal tumors were classified as plexiform yet these tumors contributed 78% of the tumor burden by volume. Conclusions: WBMRI scan is a powerful tool to evaluate the number, size, and distribution of internal tumors in patients with neurofibromatosis. This technique provides unique phenotypic information for genetic studies on NF1, NF2, and schwannomatosis. In addition, WBMRI may prove useful in identifying individual patients at high risk for complications (such as neurologic dysfunction or malignant transformation) due to heavy internal tumor burden and in determining the efficacy of antitumor drugs in this unique patient population. No significant financial relationships to disclose.