Comparison of apparent diffusion coefficient maps to T2-weighted images for target delineation in cervix cancer brachytherapy

Abstract

PurposeT2-weighted (T2W) magnetic resonance imaging (MRI) has been used for target delineation in cervix cancer brachytherapy. The objective of this study was to examine the feasibility of using diffusion-weighted magnetic resonance imaging (DWI) for target delineation as compared against T2W imaging.Material and methodsFifteen cervix cancer patients, implanted with tandem and ovoid applicators, underwent T2W turbo-spin echo imaging and DWI with a maximum diffusion factor of 800 sec/mm2 on a 1.5-T MR scanner. Apparent diffusion coefficient (ADC) maps were derived from the DWI. The gross tumor volume was manually delineated on the T2W and ADC datasets for each patient. The agreement between T2W- and ADC-delineated volumes was assessed using the Dice similarity coefficient (DSC). An algorithm was developed to compare the edge contrast of the delineated volumes on T2W images and ADC maps by calculating the percentage difference in the intensity values of selected regions of pixels inside versus outside the target contour.ResultsADC-delineated volumes were generally smaller than T2W-delineated volumes, yielding a low DSC of 0.54 ± 0.22. ADC maps were found to display superior definition of the target volume edge relative to T2W images, yielding a statistically significant difference between the mean edge contrast on ADC (12.7 ± 7.7%) versus that on T2W images (4.6 ± 3.2%; p = 0.0010).ConclusionsThese results suggest that incorporating the use of DWI for cervix cancer brachytherapy may yield gross tumor volumes that are different from those based on T2W images alone.

Place of residence does not significantly influence radiological morphology of cervical cancer

“…In the case of an advanced stage of the disease with parametrial, vesicle, rectal and low vaginal infiltration, as well as distal lymphatic and other metastasis, surgical treatment is not recommended and the patient should be treated with radio-or radio-chemotherapy [10]. The mean tumour volume among the whole examined population was relatively high (84.75 ± 66.02 mm 3 ), but similar to other studies [11][12][13][14]. The parameter is also a very important prognostic factor.…”

Three-dimensional dose accumulation in pseudo-split-field IMRT and brachytherapy for locally advanced cervical cancer

“…MR scans were performed with a titanium tandem-ovoid applicator (Varian Medical Systems, Palo Alto, CA) in situ on a 1.5 T MR scanner. MR scanning sequences included T2-weighted imaging, single-shot diffusion-weighted imaging, and proton-density weighted images in para-sagittal acquisitions (28). Patients received six weekly fractions of HDR BT (6.5e7.3 Gy per fraction).…”

Comparison of Tumor Volume Between PET and MRI in Cervical Cancer With Hybrid PET/MR

“…5,10,16,27 The current study investigated the tumor location overlap difference between MR-GTV and PET-GTV. There was a significant tumor overlap difference among the groups.…”