Verification of Range Accuracy and Correlation With Clinical Toxicity Using Offline PET/CT for Hypofractionated Proton Radiotherapy in Breast Cancer

N/ANot Yet RecruitingNCT07543107

Ruijin Hospital30 enrolled

Overview

This is a single-arm, single-center, prospective observational study. It uses offline PET/CT to verify and quantify the range accuracy of hypofractionated proton radiotherapy for postoperative breast cancer. The correlation between range error and clinical toxicities (radiation pneumonitis, rib fracture) will be analyzed. A PET signal-proton range correlation model will be established using Monte Carlo simulation to provide evidence for optimizing proton therapy planning.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Breast Cancer

Interventions

Offline PET/CT scanningOTHER

Offline PET/CT scan performed after proton therapy to verify range accuracy; no therapeutic intervention

Eligibility

Sex: FEMALEMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Written informed consent obtained. 2. Female aged ≥18 years. 3. Pathologically confirmed breast cancer after curative surgery (breast-conserving or mastectomy) and indicated for postoperative adjuvant radiotherapy. 4. Scheduled to receive moderate or ultra-hypofractionated proton therapy. 5. KPS ≥80, expected survival \>5 years. 6. Well-healed surgical incision without infection. 7. Fertile females must use contraception for ≥1 month before screening and throughout the study. Exclusion Criteria: 1. Pregnant or lactating female. 2. Severe non-neoplastic medical comorbidities precluding radiotherapy. 3. Inability to cooperate or comply with offline PET/CT examination.

Outcomes

Primary Outcomes

Proton beam range accuracy verified by offline PET/CT

Quantify the range accuracy of hypofractionated proton radiotherapy for breast cancer using offline PET/CT imaging

Time frame: During proton radiotherapy (at the time of offline PET/CT scanning)

Correlation between range error and radiation pneumonitis

Evaluate the correlation between proton range error measured by offline PET/CT and the incidence of radiation pneumonitis

Time frame: Up to 24 months after completion of proton radiotherapy

Correlation between range error and rib fracture

Evaluate the correlation between proton range error measured by offline PET/CT and the incidence of rib fracture

Time frame: Up to 24 months after completion of proton radiotherapy

Secondary Outcomes

Correlation between range error and lung dosimetric parameters

Analyze the correlation between proton range error and lung V5, V10, V20

Time frame: During proton radiotherapy

Correlation between range error and rib dosimetric parameters

Analyze the correlation between proton range error and rib Dmax, V30

Time frame: During proton radiotherapy

Performance of PET signal-proton range prediction model

Establish and evaluate the PET signal-proton range quantitative model using Monte Carlo simulation

Time frame: During proton radiotherapy