Outcome Prediction in Head&Neck Cancer Patients After Radiotherapy

Overview

The primary and general objective of the clinical introduction of the Standard Follow-up Program (SFP) as the current standard of care is to improve the quality of radiotherapy for head and neck cancer patients by reducing radiation-induced side effects without hampering treatment efficacy in terms of locoregional tumour control and overall survival and to systematically evaluate the beneficial effect of newly introduced radiation technology for this particular group of patients. The clinical introduction of the SFP will allow for a systematic and broad scale quality improvement cycle for head and neck cancer patients treated with radiotherapy. In fact, this methodology can be considered a kind of quality circle for the clinical introduction of new radiation techniques, aiming at continuous efforts for further improvement.

For head and neck squamous cell carcinoma (HNSCC), radiation therapy is one of the mainstays of therapy either as definitive therapy alone or in combination with systemic therapy or following surgical resection as postoperative treatment. Nowadays there's great attention for personalized medicine which aims at offering a patient the treatment that best suits the individual patient and its tumor characteristics. To apply personalized therapy, we need accurate outcome prediction models for disease control, treatment related toxicity and quality of life. The main factors used for predictive/prognostic nomograms are clinical factors, like patient-, tumor- and treatment related factors (1). Standard examples of these include age, gender, co-morbidity, smoking history, hemoglobin levels, tumor site, TNM stage, tumor volume, HPV-status, and others. For larynx cancer the nomogram was made publicly available on www.predictcancer.org. However, we anticipate that other factors will contribute to the (improvement of) prediction models. These factors may include genomic analysis of tumor specimens, quantitative image analysis (radiomics), blood biomarkers, and/or tumor-tissue markers (2). In addition, treatment-related parameters also need to be considered and these not only include factors like overall treatment time, use of systemic therapy, prescribed radiation dose and fraction dose. With new techniques using EPID dosimetry, it is now possible to measure the delivered radiation dose and compare this to the prescribed dose (3,4). This offers the potential to apply Dose Guide RadioTherapy (DGRT), which especially in HNSCC may have a large impact, because anatomical changes during fractionated therapy are known to occur and lead to dose changes to targets and organs at risk (5,6). The final objective of this study is to integrate all potential prognostic factors and develop reliable nomograms both for tumor control as well as complications.