The goal of this prospective observational cohort study is to evaluate the long-term efficacy and safety of ultrahypofractionated proton beam therapy in patients with localized prostate cancer and to identify clinical and treatment-related factors associated with oncologic outcomes and treatment-related toxicity.
The main questions it aims to answer are:
What are the long-term biochemical recurrence-free survival, clinical progression-free survival, overall survival, and acute and late treatment-related toxicity outcomes following ultrahypofractionated proton beam therapy? Which clinical characteristics, treatment planning parameters, and patient-reported outcomes are predictive of long-term oncologic outcomes and treatment-related toxicity?
Participants will:
Receive protocol-based ultrahypofractionated proton beam therapy (35-40 Gy\[RBE\] in 5 fractions).
Undergo routine clinical evaluation, laboratory testing including prostate-specific antigen (PSA), and imaging studies according to the institutional follow-up schedule.
Complete patient-reported outcome questionnaires (EPIC-CP and Visual Analog Scale \[VAS\]) before treatment and during follow-up.
Be followed prospectively to assess biochemical recurrence, clinical progression, survival outcomes, and acute and late treatment-related toxicities.
Histologically confirmed localized adenocarcinoma of the prostate.
No evidence of distant metastasis (M0).
Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
Eligible to receive definitive image-guided ultrahypofractionated pencil beam scanning proton beam therapy according to the study protocol.
Residual or recurrent prostate cancer following prior radical prostatectomy.
Previous pelvic radiotherapy.
Evidence of distant metastatic disease.
Active malignancy within the previous 1 year, except adequately treated basal cell carcinoma or squamous cell carcinoma of the skin, carcinoma in situ of the cervix, or completely resected T1N0M0 malignancies.