Limits...
Value of diffusion weighted MR imaging as an early surrogate parameter for evaluation of tumor response to high-dose-rate brachytherapy of colorectal liver metastases.

Wybranski C, Zeile M, Löwenthal D, Fischbach F, Pech M, Röhl FW, Gademann G, Ricke J, Dudeck O - Radiat Oncol (2011)

Bottom Line: Statistical analysis was performed using univariate comparison, ANOVA and paired t test as well as Pearson's correlation.In contrast, mean TV of liver lesions treated with HDR-BT increased by 8.8% (p = 0.054) while mean tumor ADC decreased significantly by 11.4% (p < 0.001).In contrast, mean TV of treated lesions decreased by 47.0% (p = 0.026) while the mean ADC increased inversely by 28.6% compared to baseline values (p < 0.001; Pearson's correlation coefficient of r = -0.257; p < 0.001).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Radiology and Nuclear Medicine, Otto-von-Guericke University Magdeburg, Germany.

ABSTRACT

Background: To assess the value of diffusion weighted imaging (DWI) as an early surrogate parameter for treatment response of colorectal liver metastases to image-guided single-fraction ¹⁹²Ir-high-dose-rate brachytherapy (HDR-BT).

Methods: Thirty patients with a total of 43 metastases underwent CT- or MRI-guided HDR-BT. In 13 of these patients a total of 15 additional lesions were identified, which were not treated at the initial session and served for comparison. Magnetic resonance imaging (MRI) including breathhold echoplanar DWI sequences was performed prior to therapy (baseline MRI), 2 days after HDR-BT (early MRI) as well as after 3 months (follow-up MRI). Tumor volume (TV) and intratumoral apparent diffusion coefficient (ADC) were measured independently by two radiologists. Statistical analysis was performed using univariate comparison, ANOVA and paired t test as well as Pearson's correlation.

Results: At early MRI no changes of TV and ADC were found for non-treated colorectal liver metastases. In contrast, mean TV of liver lesions treated with HDR-BT increased by 8.8% (p = 0.054) while mean tumor ADC decreased significantly by 11.4% (p < 0.001). At follow-up MRI mean TV of non-treated metastases increased by 50.8% (p = 0.027) without significant change of mean ADC values. In contrast, mean TV of treated lesions decreased by 47.0% (p = 0.026) while the mean ADC increased inversely by 28.6% compared to baseline values (p < 0.001; Pearson's correlation coefficient of r = -0.257; p < 0.001).

Conclusions: DWI is a promising imaging biomarker for early prediction of tumor response in patients with colorectal liver metastases treated with HDR-BT, yet the optimal interval between therapy and early follow-up needs to be elucidated.

Show MeSH

Related in: MedlinePlus

Early MRI 3 days after HDR-BT. Early DWI (A) and corresponding ADC map (B) performed 3 days after HDR-BT (same patient as in Figure 1) reveal a decrease in mean ADC by 27.1% to 0.94 × 10-3 mm2s-1. The ROI within the lesion indicates an ADC value of 1.09 × 10-3 mm2s-1 in this slice of the ADC map (arrow). T1w Gd-EOB-DTPA enhanced MR image in hepatobiliary phase (C) indicates no relevant change in size of the treated lesion (24.1 cm3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3111366&req=5

Figure 3: Early MRI 3 days after HDR-BT. Early DWI (A) and corresponding ADC map (B) performed 3 days after HDR-BT (same patient as in Figure 1) reveal a decrease in mean ADC by 27.1% to 0.94 × 10-3 mm2s-1. The ROI within the lesion indicates an ADC value of 1.09 × 10-3 mm2s-1 in this slice of the ADC map (arrow). T1w Gd-EOB-DTPA enhanced MR image in hepatobiliary phase (C) indicates no relevant change in size of the treated lesion (24.1 cm3).

Mentions: For ADC calculation up to three slices of the ADC map depicting the largest tumor diameter were selected, depending on the volume of the tumor. In each slice a region of interest (ROI) was delineated according to the tumor geometry. The border of the ROI was placed in the tumor periphery close to the tumor margin, so that the ROI encompassed almost the whole tumor area (Figure 3). The measurements were performed independently by two experienced investigators and the mean of the measurements was recorded as representative ADC value for each lesion. Initial and follow-up images were matched and ADC calculations were performed on corresponding sections on follow-up MRI (Figure 4).


Value of diffusion weighted MR imaging as an early surrogate parameter for evaluation of tumor response to high-dose-rate brachytherapy of colorectal liver metastases.

Wybranski C, Zeile M, Löwenthal D, Fischbach F, Pech M, Röhl FW, Gademann G, Ricke J, Dudeck O - Radiat Oncol (2011)

Early MRI 3 days after HDR-BT. Early DWI (A) and corresponding ADC map (B) performed 3 days after HDR-BT (same patient as in Figure 1) reveal a decrease in mean ADC by 27.1% to 0.94 × 10-3 mm2s-1. The ROI within the lesion indicates an ADC value of 1.09 × 10-3 mm2s-1 in this slice of the ADC map (arrow). T1w Gd-EOB-DTPA enhanced MR image in hepatobiliary phase (C) indicates no relevant change in size of the treated lesion (24.1 cm3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3111366&req=5

Figure 3: Early MRI 3 days after HDR-BT. Early DWI (A) and corresponding ADC map (B) performed 3 days after HDR-BT (same patient as in Figure 1) reveal a decrease in mean ADC by 27.1% to 0.94 × 10-3 mm2s-1. The ROI within the lesion indicates an ADC value of 1.09 × 10-3 mm2s-1 in this slice of the ADC map (arrow). T1w Gd-EOB-DTPA enhanced MR image in hepatobiliary phase (C) indicates no relevant change in size of the treated lesion (24.1 cm3).
Mentions: For ADC calculation up to three slices of the ADC map depicting the largest tumor diameter were selected, depending on the volume of the tumor. In each slice a region of interest (ROI) was delineated according to the tumor geometry. The border of the ROI was placed in the tumor periphery close to the tumor margin, so that the ROI encompassed almost the whole tumor area (Figure 3). The measurements were performed independently by two experienced investigators and the mean of the measurements was recorded as representative ADC value for each lesion. Initial and follow-up images were matched and ADC calculations were performed on corresponding sections on follow-up MRI (Figure 4).

Bottom Line: Statistical analysis was performed using univariate comparison, ANOVA and paired t test as well as Pearson's correlation.In contrast, mean TV of liver lesions treated with HDR-BT increased by 8.8% (p = 0.054) while mean tumor ADC decreased significantly by 11.4% (p < 0.001).In contrast, mean TV of treated lesions decreased by 47.0% (p = 0.026) while the mean ADC increased inversely by 28.6% compared to baseline values (p < 0.001; Pearson's correlation coefficient of r = -0.257; p < 0.001).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Radiology and Nuclear Medicine, Otto-von-Guericke University Magdeburg, Germany.

ABSTRACT

Background: To assess the value of diffusion weighted imaging (DWI) as an early surrogate parameter for treatment response of colorectal liver metastases to image-guided single-fraction ¹⁹²Ir-high-dose-rate brachytherapy (HDR-BT).

Methods: Thirty patients with a total of 43 metastases underwent CT- or MRI-guided HDR-BT. In 13 of these patients a total of 15 additional lesions were identified, which were not treated at the initial session and served for comparison. Magnetic resonance imaging (MRI) including breathhold echoplanar DWI sequences was performed prior to therapy (baseline MRI), 2 days after HDR-BT (early MRI) as well as after 3 months (follow-up MRI). Tumor volume (TV) and intratumoral apparent diffusion coefficient (ADC) were measured independently by two radiologists. Statistical analysis was performed using univariate comparison, ANOVA and paired t test as well as Pearson's correlation.

Results: At early MRI no changes of TV and ADC were found for non-treated colorectal liver metastases. In contrast, mean TV of liver lesions treated with HDR-BT increased by 8.8% (p = 0.054) while mean tumor ADC decreased significantly by 11.4% (p < 0.001). At follow-up MRI mean TV of non-treated metastases increased by 50.8% (p = 0.027) without significant change of mean ADC values. In contrast, mean TV of treated lesions decreased by 47.0% (p = 0.026) while the mean ADC increased inversely by 28.6% compared to baseline values (p < 0.001; Pearson's correlation coefficient of r = -0.257; p < 0.001).

Conclusions: DWI is a promising imaging biomarker for early prediction of tumor response in patients with colorectal liver metastases treated with HDR-BT, yet the optimal interval between therapy and early follow-up needs to be elucidated.

Show MeSH
Related in: MedlinePlus