Pretreatment ADC is not a prognostic factor for local recurrences in head and neck squamous cell carcinoma when clinical T-stage is known

Abstract

Objectives Pretreatment identification of radio-insensitive head and neck squamous cell carcinomas (HNSCC) would affect treatment modality selection. The apparent diffusion coefficient (ADC) of a tumor could be a predictor of local recurrence. However, little is known about its prognostic value next to known factors such as clinical T-stage. The aim of the present study is to determine the added value of pretreatment ADC to clinical T-stage as a prognostic factor for local recurrence. Methods This retrospective cohort study included 217 patients with HNSCC treated with (chemo)radiotherapy between April 2009 and December 2015. All patients underwent diffusion-weighted MRI prior to treatment. Median ADC values of all tumors were obtained using a semi-automatic delineation method. Univariate models containing ADC and T-stage were compared with a multivariable model containing both variables. Results Fifty-eight patients experienced a local recurrence within 3 years. On average, the ADC value in the group of patients with a recurrence was 1.01 versus 1.00 (10 −3 mm 2 /s) in the group without a recurrence. Univariate analysis showed no significant association between tumor ADC and local recurrence within 3 years after (chemo)radiotherapy (p = 0.09). Cox regression showed that clinical T-stage was an independent predictor of local recurrence and adding ADC to the model did not increase its performance. Conclusion Pretreatment ADC has no added value as a prognostic factor for local recurrence to clinical T-stage. Key Points • Pretreatment identification of head and neck squamous cell carcinoma patients who do not benefit from (chemo)radiotherapy could improve personalized cancer care. • The apparent diffusion coefficient (ADC) obtained from diffusion-weighted MRI has been reported to be a prognostic factor for local recurrence. • In this study, ADC has no added value as a prognostic factor compared with clinical T-stage.

PET measured hypoxia and MRI parameters in re-irradiated head and neck squamous cell carcinomas: findings of a prospective pilot study

“…Only in one tumor (patient #7), the average ADC was below 1,000 × 10 6 mm 2 /s. These MRI findings are consistent with the literature [28][29][30] . Hwang et al reported average ADC values of 1,200 × 10 6 mm 2 /s in patients with recurrent HNSCC after initial treatment compared to an average of 1,650 × 10 6 mm 2 /s in lesions corresponding to post-therapeutic changes 30 .…”

PET measured hypoxia and MRI parameters in re-irradiated head and neck squamous cell carcinomas: findings of a prospective pilot study

“…Only in one tumor (patient #7), the average ADC was below 1,000 × 10 6 mm 2 /s. These MRI findings are consistent with the literature [28][29][30] Moreover, ADC values as high as 1,000 × 10 6 mm 2 /s were only observed in tumors with hypoxic volumes <10% of the total tumor volume 32 . In contrast, a positive correlation was reported in murine melanoma tumors (but imaging was performed ex vivo) 33 .…”

Clinical utility of apparent diffusion coefficient and diffusion‐weighted magnetic resonance imaging for resectability assessment of head and neck tumors with skull base invasion

“…The limitations of this study include the small number of patients and the diversity of the tumor locations and histology as well as the MRI equipment used and technical parameters, such as magnetic field (1.5 and 3 T), DW sequences (EPI and TSE DWI), and TR/TE have great influence on the ADC values 16,17 . ADC values have been reported to vary by histological type in head and neck malignancies 18‐21 although there was no difference between histology and subsite in this study. Thus, the ratio of ADC values in regions of skull base invasion/main tumor was also calculated in this study.…”