Radiation oncologists collect the patient's medical history and conduct necessary examinations to assess whether proton radiotherapy is suitable for the patient. Based on the evaluation, treatment plan will be determined.

Once the treatment plan is confirmed, technicians will create personalized immobilization devices (such as thermoplastic masks or vacuum bags) tailored to the patient’s treatment area. These devices ensure high reproducibility of the patient’s position during treatment, which is essential for precise radiotherapy

After immobilization, the patient undergoes a CT scan (CT-sim) to obtain dedicated DICOM images. If necessary, an MRI scan (MRI-sim) may also be performed. Preoperative/postoperative or pre-chemotherapy/ post-chemotherapy MRI, CT, or PET images are imported into the system and fused with the CT-sim images to accurately contour the tumor location and extent. This step is critical for optimizing treatment planning and ensuring precise radiotherapy delivery.

Using the CT-sim and fused images, radiation oncologists delineate the precise boundaries of the tumor and identify normal tissues that need protection. They then prescribe the appropriate radiation dose and fractionation for the tumor target area while setting tolerance doses for surrounding healthy tissues.

Based on the prescribed dose and target volume, medical physicists use the treatment planning system to design the number and direction of radiation fields. Through iterative optimization, they achieve the best possible dose distribution and treatment plan. Radiation oncologists evaluate the plan to ensure it meets the dose requirements for both the target area and normal tissues with the best dose optimization.

The proton radiotherapy plan is verified under simulated treatment conditions to ensure its safety, accuracy and feasibility. The plan is only approved for actual treatment after successful verification.

Technicians position the patient according to the immobilization conditions and take verification images. After confirming precise positioning through image guidance, the treatment is delivered based on the treatment plan. Each fraction generally lasts 20–30 minutes.

Patients see physicians weekly during radiotherapy. Radiation oncologists actively monitor and manage acute side effects, track tumor regression, and adjust the treatment plan as needed.

The follow-up schedule is determined by the patient’s specific condition and disease type. Generally, patients are advised to attend follow-up visits every 3 months for the first 1–2 years after treatment, every 6 months for year 3–5, and annually thereafter. Tumor control will be evaluated and any long-term side effects will be monitored, recorded and managed.