Dynamic contrast-enhanced magnetic resonance imaging of radiation therapy-induced microcirculation changes in rectal cancer

Journal Article · Thu Dec 01 04:00:00 EST 2005 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2005.0· OSTI ID:20788220

Lussanet, Quido G. de . ^[1]; Backes, Walter H ^[2]; Griffioen, Arjan W ^[3]; Padhani, Anwar R ^[4]; Baeten, Coen I ^[3]; Baardwijk, Angela van ^[5]; Lambin, Philippe ^[5]; Beets, Geerard L ^[6]; Engelshoven, Jos van ^[2]; Beets-Tan, Regina G.H. ^[2]

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1. Department of Radiology, Maastricht University Hospital, Maastricht (Netherlands) and Cardiovascular Research Institute Maastricht - CARIM, Maastricht University, Maastricht (Netherlands)
2. Department of Radiology, Maastricht University Hospital, Maastricht (Netherlands)
3. Angiogenesis Laboratory, Department of Pathology and Internal Medicine, Maastricht University Hospital, Maastricht (Netherlands)
4. Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom)
5. Research Institute for Growth and Development (GROW), Maastricht University, Maastricht (Netherlands)
6. Department of Surgical Oncology, Maastricht University Hospital, Maastricht (Netherlands)

Purpose: Dynamic contrast-enhanced T1-weighted magnetic resonance imaging (DCE-MRI) allows noninvasive evaluation of tumor microvasculature characteristics. This study evaluated radiation therapy related microvascular changes in locally advanced rectal cancer by DCE-MRI and histology. Methods and Materials: Dynamic contrast-enhanced-MRI was performed in 17 patients with primary rectal cancer. Seven patients underwent 25 fractions of 1.8 Gy radiation therapy (RT) (long RT) before DCE-MRI and 10 did not. Of these 10, 3 patients underwent five fractions of 5 Gy RT (short RT) in the week before surgery. The RT treated and nontreated groups were compared in terms of endothelial transfer coefficient (K{sup PS}, measured by DCE-MRI), microvessel density (MVD) (scored by immunoreactivity to CD31 and CD34), and tumor cell and endothelial cell proliferation (scored by immunoreactivity to Ki67). Results: Tumor K{sup PS} was 77% (p = 0.03) lower in the RT-treated group. Histogram analyses showed that RT reduced both magnitude and intratumor heterogeneity of K{sup PS} (p = 0.01). MVD was significantly lower (37%, p 0.03) in tumors treated with long RT than in nonirradiated tumors, but this was not the case with short RT. Endothelial cell proliferation was reduced with short RT (81%, p = 0.02) just before surgery, but not with long RT (p > 0.8). Tumor cell proliferation was reduced with both long (57%, p < 0.001) and short RT (52%, p = 0.002). Conclusion: Dynamic contrast-enhanced-MRI-derived K{sup PS} values showed significant radiation therapy related reductions in microvessel blood flow in locally advanced rectal cancer. These findings may be useful in evaluating effects of radiation combination therapies (e.g., chemoradiation or RT combined with antiangiogenesis therapy), to account for effects of RT alone.

• OSTI ID: 20788220
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 5 Vol. 63; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BLOOD FLOW
CELL PROLIFERATION
EVALUATION
HISTOLOGY
NEOPLASMS
NMR IMAGING
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RADIOTHERAPY
SURGERY
TUMOR CELLS