This study is testing a shorter treatment method for prostate cancer using proton therapy (PT), which is very precise and may cause fewer side effects compared to traditional radiation. However, it is expensive and not easily accessible for many patients. To make it more affordable and accessible, this study is testing whether 2 fractions of stereotactic body proton therapy (SBPT) can be as safe and effective as the standard 5 sessions.
Proton therapy is an advanced form of radiation that precisely targets tumors while minimizing damage to healthy tissues. However, its high cost has limited patient access. For prostate cancer, studies have already shown that ultra-short radiation courses (as few as 2-5 sessions) using conventional X-ray-based stereotactic body radiation therapy (SBRT) provide excellent results with manageable side effects. This study aims to investigate whether 2-fraction stereotactic body proton therapy (SBPT) with magnetic resonance imaging (MRI) guidance and real-time on-board tumor tracking can achieve similar safety and efficiency as the standard 5-fraction SBPT, with the added benefit of lower costs and greater convenience for patients.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
35
2 fractions will be delivered to treat low- or intermediate- risk prostate cancer
Hong Kong Sanatorium and Hospital
Hong Kong, Hong Kong
Clinician-reported grade 2 or above genitourinary and gastrointestinal toxicity
Genitourinary and gastrointestinal toxicity were evaluated based on the Common Terminology Criteria for Adverse Events (CTCAE, version 5.0) developed by the National Cancer Institute (NCI). Adverse effects within 3 months post-treatment are classified as acute toxicities, while those occurring after 3 months are considered late toxicities.
Time frame: 3 months and 24 months after treatment completion with a minimum of 24 months of follow-up and an average of 5 years.
Change in patient reported gastrointestinal and genitourinary symptoms
Gastrointestinal and genitourinary health-related quality of life (HQOL) are measured using the Expanded Prostate Cancer Index Composite (EPIC) questionnaire, which is a validated comprehensive instrument to measure the health-related quality of life among men with prostate cancer. EPIC consists of 5 primary domains, including urinary function, bowel habits, sexual function, hormonal functions, and overall satisfaction. Responses to each question form a Likert scale and are transformed to a 0-100 scale for each domain and subdomain, higher scores representing better HQOL.
Time frame: before treatment to 3-months and 24-months after treatment completed
Biochemical Progression Free Survival (bPFS)
Biochemical progression-free survival (bPFS) among participants will be assessed during clinical follow-up. bPFS is defined as the duration of time a localized prostate cancer patient remains free from biochemical recurrence after treatment. Biochemical recurrence is defined as a prostate-specific antigen (PSA) increase of 2 ng/mL above the nadir based on the Phoenix criteria (nadir + 2 ng/mL), confirmed by a second PSA value obtained three or more weeks later.
Time frame: Treatment completion date to 5 years follow-up
Distant Metastasis Free Survival
Distant metastasis (DM) refers to the spread of cancer cells from the prostate to distant sites outside the pelvic region. DF will be assessed during clinical follow-up using prostate-specific membrane antigen positron emission tomography (PSMA-PET), MRI, and/or other clinical imaging in cases of persistent PSA progression or emergence of symptoms. Distant metastasis free survival is defined as the duration of time from treatment completion date to the date of distant metastasis diagnosis by clinical imaging or death.
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Time frame: Treatment completion date to 5 years follow-up
Local Failure-Free Survival (LFFS)
Local Failure (LF) refers to recurrent prostatic mass diagnosed by digital rectal examination, clinical imaging techniques like PSMA-PET and/or MRI, or histopathological confirmation of recurrence by biopsy. Local failure-free survival is defined as the duration of time from treatment completion date to date of local failure diagnosis or death.
Time frame: Treatment completion date to 5 years follow-up
Regional Failure Free Survival (RFFS)
Regional Failure (RF) refers to recurrent in the regional lymph nodes diagnosed by clinical imaging techniques like PSMA-PET and/or MRI. Regional failure-free survival is defined as the duration of time from treatment completion date to date of regional failure diagnosis or death.
Time frame: Treatment completion date to 5 years follow-up