A magnetic resonance imaging-based approach to quantify radiation-induced normal tissue injuries applied to trismus in head and neck cancer

Abstract

Background and Purpose In this study we investigated the ability of textures from T1-weighted MRI scans post-contrast (T1wpost) to identify the critical muscle(s) for radiation-induced trismus. Materials and Methods The study included ten cases (Trismus: ≥Grade 1), and ten age-sex-tumor-location-and-stage-matched controls treated with intensity-modulated radiotherapy to 70Gy@2.12Gy in 2005–2009. Trismus status and T1wPost were conducted within one year post-radiotherapy. For the masseter, lateral and medial pterygoids, and temporalis (M/LP/MP/T), 24 textures were extracted (Grey Level Co-Occurrence (GLCM), Histogram, and Shape). Univariate logistic regression with Bootstrapping (1000 populations) was applied to compare the muscle mean dose (Dmean) and textures between cases and controls (ipsilateral muscles); candidate predictors were suggested by an average p≤0.20 across all Bootstrap populations. Results Dmean to M/LP/MP (p=0.03/0.14/0.09), one MP/T (p=0.12/0.17), and three M (p=0.14–0.19) textures were candidate predictors. Three of these textures were GLCM- and two Histogram textures with the former being generally higher and the latter lower for cases compared to controls. The Dmean to M and MP, and Haralick Correlation (GLCM) of MP presented with the best discriminative ability (area under the receiver-operating characteristic curve: 0.85, 0.77, and 0.78), and the correlation between Dmean and this texture was weak (Spearman’s rank correlation coefficient: 0.26–0.27). Conclusions Our exploratory study points towards an interplay between the dose to the masseter, and the medial pterygoid together with the local relationship between the mean MRI intensity relative to its variance of the medial pterygoid for radiation-induced trismus. This opens up for exploration of this interplay within the radiation-induced trismus etiology in the larger multi-institutional setting.

Exploring Applications of Radiomics in Magnetic Resonance Imaging of Head and Neck Cancer: A Systematic Review

“…Only four studies (25%) derived texture features from a single MRI sequence. Thor et al ( 45 ) extracted 24 textures, containing first- and second-order features, from T1-weighted post-contrast images to quantify radiation-induced trismus. Brown et al ( 36 ) investigated whether 21 texture features from a set of 300 DWI MRI parameters could reliably predict histopathological classification of thyroid tumors.…”

“…Magnetic resonance imaging radiomics is not limited to studies of tumors alone. Radiomic signatures can predict RT-related toxicities in normal tissues, such as radiation-induced trismus ( 45 ), or they can be designed to autosegment parotid glands post-RT ( 46 ). Future studies should investigate whether radiomic features could predict the effects of RT-related toxicities on quality of life or if changes in corresponding critical organ volumes, such as structures involved in the swallowing mechanism, can be estimated.…”

Radiomics for radiation oncologists: are we ready to go?

“…88 A more limited number of studies has also shown potentially useful preliminary results for CT-based prediction of radiationinduced changes in breast tissue during accelerated partial breast irradiation, 89 sensorineural hearing loss in HNC radiochemotherapy 90 ; and for MRI-based prediction of trismus in HNC RT. 91 The potential advantages of general radiomic-based textural analysis to predict toxicity are therefore wideranging and need further investigation in order to be extended into the physicians' practice. This would help to select patients who will benefit most from highly conformational and/or adaptive RT, e.g.…”

Texture analysis of T1‐w and T2‐w MR images allows a quantitative evaluation of radiation‐induced changes of internal obturator muscles after radiotherapy for prostate cancer

“…In recent years, the analysis of anatomic MRI, such as T2w and T1-w MRI, with and without contrast agent (CA) injection, has been carried out in some studies to assess radiationinduced effects in muscles, especially after radiotherapy for head and neck cancer (HNC). [17][18][19] Pelvic floor muscles were qualitatively evaluated before and after prostate cancer radiotherapy, focusing, in particular, on internal obturator muscles and levator ani muscles. 20 MRI findings revealed an increase in T2-w signal and T1-w contrast enhancement, compatible with a radiation-induced inflammation.…”