Publication
Tumour ADC measurements in rectal cancer: effect of ROI methods on ADC values and interobserver variability
| dc.contributor.author | Lambregts, DM | |
| dc.contributor.author | Beets, GL | |
| dc.contributor.author | Maas, M | |
| dc.contributor.author | Curvo-Semedo, L | |
| dc.contributor.author | Kessels, AG | |
| dc.contributor.author | Thywissen, T | |
| dc.contributor.author | Beets-Tan, RG | |
| dc.date.accessioned | 2012-02-16T11:55:53Z | |
| dc.date.available | 2012-02-16T11:55:53Z | |
| dc.date.issued | 2011 | |
| dc.description.abstract | OBJECTIVES: To assess the influence of region of interest (ROI) size and positioning on tumour ADC measurements and interobserver variability in patients with locally advanced rectal cancer (LARC). METHODS: Forty-six LARC patients were retrospectively included. Patients underwent MRI including DWI (b0,500,1000) before and 6-8 weeks after chemoradiation (CRT). Two readers measured mean tumour ADCs (pre- and post-CRT) according to three ROI protocols: whole-volume, single-slice or small solid samples. The three protocols were compared for differences in ADC, SD and interobserver variability (measured as the intraclass correlation coefficient; ICC). RESULTS: ICC for the whole-volume ROIs was excellent (0.91) pre-CRT versus good (0.66) post-CRT. ICCs were 0.53 and 0.42 for the single-slice ROIs versus 0.60 and 0.65 for the sample ROIs. Pre-CRT ADCs for the sample ROIs were significantly lower than for the whole-volume or single-slice ROIs. Post-CRT there were no significant differences between the whole-volume ROIs and the single-slice or sample ROIs, respectively. The SDs for the whole-volume and single-slice ROIs were significantly larger than for the sample ROIs. CONCLUSIONS: ROI size and positioning have a considerable influence on tumour ADC values and interobserver variability. Interobserver variability is worse after CRT. ADCs obtained from the whole tumour volume provide the most reproducible results. Key Points • ROI size and positioning influence tumour ADC measurements in rectal cancer • ROI size and positioning influence interobserver variability of tumour ADC measurements • ADC measurements of the whole tumour volume provide the most reproducible results • Tumour ADC measurements are more reproducible before, rather than after, chemoradiation treatment • Variations caused by ROI size and positioning should be taken into account when using ADC as a biomarker for tumour response. | por |
| dc.identifier.citation | Eur Radiol. 2011;21(12):2567-74. | por |
| dc.identifier.uri | http://hdl.handle.net/10400.4/1311 | |
| dc.language.iso | eng | por |
| dc.peerreviewed | yes | por |
| dc.publisher | Springer | por |
| dc.subject | Neoplasias do Recto | por |
| dc.title | Tumour ADC measurements in rectal cancer: effect of ROI methods on ADC values and interobserver variability | por |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | por |
| rcaap.type | article | por |