Prognostic MRI parameters in laryngeal cancer and lymphatic metastasis

Castelijns, J.A. [Promotor]Leemans, C.R. [Promotor]Langendijk, J.A. [Promotor]Hoekstra, O.S. [Copromotor

Diffusion-Weighted Imaging of the Head and Neck in Healthy Subjects: Reproducibility of ADC Values in Different MRI Systems and Repeat Sessions

Background and Purpose: DWI is typically performed with EPI sequences in single-center studies. The purpose of this study was to determine the reproducibility of ADC values in the head and neck region in healthy subjects. In addition, the reproducibility of ADC values in different tissues was assessed to identify the most suitable reference tissue. Materials and Methods: Weprospectively studied 7 healthy subjects, with EPI and TSE sequences, on 5MR imaging systems at 3 time points in 2 institutions. ADC maps of EPI (with 2b-values and 6b-values) and TSE sequences were compared. Mean ADC values for different tissues (submandibular gland, sternocleidomastoid muscle, spinal cord, subdigastric lymph node, and tonsil) were used to evaluate intraand intersubject, intersystem, and intersequence variability by using a linear mixed model. Results: On 97% of images, a region of interest could be placed on the spinal cord, compared with 87% in the tonsil. ADC values derived from EPI-DWI with 2b-values and calculated EPI-DWI with 2b-values extracted from EPI-DWI with 6b-values did not differ significantly. The standard error of ADC measurement was the smallest for the tonsil and spinal cord (standard error of measurement = 151.2 × 1

Has the degree of contrast enhancement with MR imaging in laryngeal carcinoma added value to Anatomic parameters regarding prediction of response to radiation therapy?

BACKGROUND AND PURPOSE: Our aim was to retrospectively investigate the prognostic significance of the degree of contrast enhancement in tumors and its additional value in previously considered MR imaging parameters with regard to local control of laryngeal cancer treated with radiation therapy (RT) alone. MATERIALS AND METHODS: Pretreatment MR images of 64 consecutive patients (54 men and 10 women, 43-80 years of age) with supraglottic and glottic cancer were retrospectively reviewed on clinical and previously considered MR imaging parameters such as tumor involvement of specific laryngeal anatomic subsites, including laryngeal cartilages, tumor volume, extralaryngeal tumor spread, and, in addition, the degree of contrast enhancement. Clinical and MR imaging parameters were associated with regard to local control at 2 years by using the Cox regression model. "Local control" was defined as absence of primary tumor recurrence. RESULTS: When using a threshold of the mean average contrast enhancement of 77%, the 2-year local control rate in the groups of patients with a degree of enhancement below and above this threshold was 57% and 70%, respectively (P =.3). Enhancement of tumor tissue in pre-epiglottic space (PES) was low, most probably due to its adipose tissue and poor vascular content, whereas tumor tissue involving paraglottic space (PGS) did enhance. Results of multivariate analysis indicated that the degree of contrast enhancement yielded the prognostic information (P =.07) with 2 independent prognostic factors: primary tumor volume (P =.007) and subglottic extension (P =.002) with regard to local control. Using these previously mentioned 3 MR imaging parameters as potential risk factors, we defined 4 categories, resulting in the following local control rates respectively: 90% for the group without risk factors, 73% for the group with 1, 60% for the group with 2, and finally 0% for the group with 3 risk factors, which was significantly lower than the rates in previous risk groups (P CONCLUSION: PES has a lower degree of contrast enhancement than the PGS and may correlate with the worse outcome. Including a low degree of contrast enhancement as a parameter to primary tumor volume and subglottic extension may increase the predictive value of MR imaging for local outcome and may be helpful to identify a subset of patients whose tumors all recurred locally within 2 years after primary RT