Has the Degree of Contrast Enhancement with MR Imaging in Laryngeal Carcinoma Added Value to Anatomic Parameters Regarding Prediction of Response to Radiation Therapy?
R. Ljumanovica,
P.J.W. Pouwelsb,
J.A. Langendijkf,
D.L. Knolc,
P. van der Valkd,
C.R. Leemanse and
J.A. Castelijnsa
a Department of Radiology, VU University Medical Center, Amsterdam, the Netherlands
b Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, the Netherlands
c Department of Clinical Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, the Netherlands
d Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands
e Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, Amsterdam, the Netherlands
f Department of Radiation Oncology, University Medical Center Groningen, Groningen, the Netherlands
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Fig 1. The degree of contrast enhancement was calculated by using the following formula: Degree of contrast enhancement (%) = [(SIPostcontrast – SIPrecontrast) / SIPrecontrast] x 100. Comparison of the degree of contrast enhancement measured within the tumor (range, 39%–119%) and normal tissue (range, 2%–46%) on T1-weighted MR images (T1WIs) in 64 patients with laryngeal carcinoma.
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Fig 2. Axial T1-weighted MR images (600/15 ms [TR/TE]) before (A) and after (B) contrast administration. In this example, the SI of the supraglottic mass increases from 312 to 521 within tumor area (arrows), leading to a degree of contrast enhancement of (521–312)/ 312 = 67%. The tumor was considered as a low-enhanced tumor, which locally recurred within 11 months after RT.
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Fig 3. Axial T1-weighted MR images (600/15 ms [TR/TE]) before (A) and after (B) contrast administration show a supraglottic mass with the SI that increases from 246 to 513 within the tumor area (arrows). The degree of contrast enhancement was (572–272)/272 = 110%. The tumor was considered a high-enhanced tumor. Local recurrence was not documented within 24 months after RT.
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Fig 4. Comparison of the degree of contrast enhancement measured within the tumor in PES (range, 15%–95%) and tumor in PGS normal tissue (range, 64%–161%) on T1-weighted MR images in 17 patients with laryngeal carcinoma. A statistical difference was found between these 2 spaces (P = .006).
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Fig 5. Axial T1-weighted MR images (500/15 ms [TR/TE]) before (A) and after (B) contrast administration. In this illustration, the SI of the tumor mass at the right side on the false vocal cord level, involving the PES, increases from 228 to 445 within the tumor area and, involving the PGS, from 221 to 576 (arrows). The degree of contrast enhancement was 95% for a tumor in the PES and 160% for a tumor in the PGS.
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Fig 6. Patients with low-enhanced laryngeal tumor tissue (below 77%, dotted line, n = 36) show poor prognosis (2-year local control rate, 57%) compared with high-enhanced laryngeal tumor tissue (equal or above 77%, solid line, n = 28) (2-year local control rate, 70%).
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Fig 7. Patients with 3 MR imaging–determined risk factors are at high risk for local control (1-year local control rate, 0%). MR imaging risk factors are large tumor volume (>4 mL), subglottic extension, and low degree of enhancement. No risk factors (n = 10), 1 risk factor (n = 24), 2 risk factors (n = 22), 3 risk factors (n = 8). No factors versus 1 factor (P = .6), no factors versus 2 factors (P = .1), no factors versus 3 factors (P = .001).
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