Something for Everyone From Low-Risk to High-Risk: 5 Recent Studies to Improve Treatment and Surveillance for All Patients With Squamous Cell Carcinoma of the Head and Neck

Improving outcome prediction in oropharyngeal carcinoma through the integration of diffusion-weighted magnetic resonance imaging radiomics

Background and purpose

Locoregional recurrence (LRR) is the primary pattern of failure in head and neck cancer (HNC) following radiation treatment (RT). Predicting an individual patient's LRR risk is crucial for pre-treatment risk stratification and treatment adaptation during RT. This study aimed to evaluate the feasibility of integrating pre-treatment and mid-treatment diffusion-weighted (DW)-MRI radiomic parameters into multivariable prognostic models for HNC.

Materials and methods

A total of 178 oropharyngeal cancer (OPC) patients undergoing (chemo)radiotherapy (CRT) were analyzed on DW-MRI scans. 105 radiomic features were extracted from ADC maps. Cox regression models incorporating clinical and radiomic parameters were developed for pre-treatment and mid-treatment phases. The models' discriminative ability was assessed with the Harrel C-index after 5-fold cross-validation.

Results

Gray Level Co-occurrence Matrix (GLCM)-correlation emerged as a significant pre-treatment radiomic predictor of locoregional control (LRC) with a C-index (95 % CI) of 0.66 (0.57-0.75). Significant clinical predictors included HPV status, stage, and alcohol use, yielding a C-index of 0.70 (0.62-0.78). Combining clinical and radiomic data resulted in a C-index of 0.72 (0.65-0.80), with GLCM-correlation, disease stage and alcohol use as significant predictors. The mid-treatment model, which included delta (Δ) mean ADC, stage, and additional chemotherapy, achieved a C-index of 0.74 (0.65-0.82). Internal cross-validation yielded C-indices of 0.60 (0.51-0.69), 0.56 (0.44-0.66), and 0.63 (0.54-0.73) for the clinical, combined, and mid-treatment models, respectively.

Conclusion

The addition of Δ ADC improves the clinical model, highlighting the potential complementary value of radiomic features in prognostic modeling.

Comparison of 3-year local control using DAHANCA radiotherapy guidelines before and after implementation of five millimetres geometrical GTV to high-dose CTV margin

INTRODUCTION

Treatment planning using a five-millimetre geometrical margin from GTV to high-dose CTV (CTV1) has been used in DAHANCA treatment centres since 2013. We aimed to evaluate changes in CTV1 volumes, local control (LC), and recurrence pattern after the implementation of five-millimetre geometrical margins nationally.

MATERIALS AND METHODS

1,948 patients with pharyngeal, and laryngeal squamous cell carcinomas completed definitive IMRT-based treatment in 2010-2012 and 2013-2015 in three centres. The patient-specific margin was calculated as median surface distance from primary tumour GTV (GTV-T) to CTV1. Radiologically verified local recurrences were analysed using a centre of mass (COM) of the delineated recurrence volume, measuring the shortest distance between COM to GTV-T and CTV1 boundaries.

RESULTS

Median GTV-CTV1 was 0.9 (0.0-0.97) and 0.47 cm (0.4-0.5) for 2010-2012 and 2013-2015, respectively. Median CTV1 changed in three centres from 76, 28, 42 cm3 to 61, 53, 62 cm3 for 2010-2012 and 2013-2015, respectively. Local failures occurred at 247 patients during first three years after radiotherapy. The 3-year LC rate for 2010-2012 and 2013-2015 was 0.84 and 0.87 (p = 0.06). Out of 146 radiology-verified analysable local recurrences, 102 (69.9%) were inside the CTV1. In 74.6% and 91% of cases, the LRs were covered by 95% isodose in 2010-2012 and 2013-2015, respectively.

CONCLUSION

DAHANCA radiotherapy guidelines based on a geometrically generated isotropic CTV1 margin led to less variation in treatment volumes and between centres than previous guidelines. The transition towards consensus GTV-CTV1 margins did not influence local tumour control. The majority of local recurrences were inside CTV1 and covered by the prescription dose.