The aim of this study is to evaluate the effect of two decision aids for renal cell carcinoma (RCC) on the decision-making process and the quality of the decision.

Background: Treatment options for patients diagnosed with RCC depend on the stage of the disease, histopathology and patient's preferences and values regarding outcomes. For local (non-metastatic) disease, gold standard for treatment is surgical resection of the tumour. Besides this, ablative therapies or active surveillance could also be an option. For metastatic disease, targeted therapy and/or immunotherapy can be offered and new treatment options are being tested in clinical trials. The number of available treatment options for patients with RCC is increasing, but the availability of these options differs per hospital and the transparency about treatment options is limited, resulting in practice variation between hospitals.

Decision aids help patients to make decisions regarding treatment, particularly when there is not one medically superior treatment option. In this tools treatment options are explained, including outcome information such as possible side effects and benefits of therapy. Decision aids have proven to lead to increased patient knowledge, less anxiety in patients, improved health outcomes such as physical en mental health, reductions in unwarranted variation in care and costs, greater alignment of care with patients' values.

For patients with RCC, two decision aids are in development right now: one decision aid focussed on local disease and one decision aid focussed on metastatic disease. Using these decision aids, patients are encouraged to make a well-informed decision together with the healthcare professional.

Objective: To assess how the decision aids for RCC influence the quality of the decision-making processes for RCC, defined as the extent to which elements of shared decision-making (SDM) are observed.

Design, setting and participants: This study includes patients clinically diagnosed with RCC, facing a decision which is addressed in the decision aids. Study design will be a prospective multicenter pre-test post-test study.

Outcome measurements and statistical analysis: The primary endpoint of this study is the mean change in OPTION-5 score between pre-test and post-test groups. Secondary outcome measures include perceived quality of the decision-making process, quality of the decision and implementation of the decision aids.

Inclusion Criteria:

• Patients clinically diagnosed with RCC
• Patients facing a decision which is addressed in the decision aids (T1 tumor or metastatic disease)
• Written informed consent

Exclusion Criteria:

• Patients who are not able to fill in a questionnaire or undergo an interview individually

Patients clinically diagnosed with RCC