The goal of this randomised clinical trial is to assess whether personalised treatment counselling can improve the decision-making experience in patients with a new diagnosis of localised prostate cancer. The main question it aims to answer is:

• Does the Bespoke Decision Support tool reduce decisional conflict in those choosing between treatment options for localised prostate cancer?

Researchers will compare the addition of the Bespoke Decision Support tool to standard treatment counselling versus standard counselling alone.

Patient participants will:

• Receive standard counselling with or without access to the Bespoke Decision Support tool (based on arm of randomisation), prior to making a treatment decision.
• Answer to questionnaires regarding urinary, sexual and bowel function and decision-making outcomes before and after making a treatment decision and at 3, 6, and 12 months after initiating treatment.
• Take part in a qualitative interview to discuss their decision-making experience

Health Care Professional participants will:

• Take part in a qualitative interview to discuss their experience in providing decision support in the trial using the Bespoke Decision Support tool.

Recruited patient participants will be randomised into two arms:

• Standard of Care (SOC) arm: SOC counselling
• Intervention arm: SOC counselling plus access to BeSpoke Decision Support

The standard of care (SOC) arm includes the nationally-approved Prostate Cancer UK booklet "Prostate Cancer - A guide if you have recently been diagnosed" and patient appointments to discuss different treatments with clinicians, as per local practice that offer them. Further educational material may be provided as per local practice at each site.

The intervention arm will offer additional BeSpoke Decision Support providing:

• Consistent and up-to-date information about suitable treatment approaches.
• Risk-stratified predictions of treatment outcomes based on baseline cancer and patient characteristics.
• Value clarification about which attributes of treatment are most important to the individual.

All participants will complete questionnaires on demographic data, functional status and measures of decision-making experiences at several time points: enrolment (prior to treatment discussion consultation); after treatment decision has taken place; at 3, 6, and 12 months after treatment commences.

The investigators will interview health care professionals and a sample of patient participants to assess the effect of the BeSpoke Decision Support and the challenges in implementation across the NHS.

Inclusion Criteria for Patient-Participants:

1. Newly diagnosed localised prostate cancer

2. Clinically suitable for at least two of the following treatment options:

   1. active surveillance
   2. focal therapy
   3. radical prostatectomy
   4. external beam radiotherapy

3. Willing and able to provide informed consent

Exclusion Criteria for Patient Participants:

1. Unsuitable for active treatment due to very low risk prostate cancer or significant health issues.

2. Suspicion of metastatic prostate cancer based on clinical or imaging evidence including:

   1. Imaging identified suspicious lesion on bone scan, CT, whole-body MRI or PSMA-PET/CT;
   2. PSA ≥50 ng/mL.

3. Not able to provide informed consent.

4. Insufficient English proficiency for adequate use of BeSpoke Decision Support. (Patients with support from a family member, friend or partner, to overcome lack of English proficiency will be included.)

5. Enrolled in other localised prostate cancer studies where treatment is assigned rather than chosen by participants, e.g. PART Trial (Partial prostate Ablation vs Radical prostaTectomy)

Inclusion criteria for Health Care Professionals:

1. Have seen BeSpoke Decision Support and spoken to patients in the intervention arm.
2. Willing and able to provide written or electronic informed consent

Exclusion criteria for Health Care Professionals

1. No experience of BeSpoke Decision Support.

Any request to share IPD from other researchers will be evaluated by the Trial Steering Committee on an ad hoc basis.