Carbon Ion Followed by Proton Radiotherapy for Prostate Cancer With Pelvic Lymph Nodes Metastases

Carbon Ion Boost Followed by Pelvic Proton Radiotherapy for Prostate Cancer With Pelvic Lymph Nodes Metastases: Prospective Phase II Study

The present of clinically pelvic lymph node positive (cN1) represent one of the most important prognostic factors for recurrence and cancer-specific mortality of prostate cancer patients. Approximately 12% of prostate cancer patients present with cN1 disease at the time of diagnosis. Furthermore, with the advent of more sensitive advance diagnostic imaging techniques, such as PSMA PET/CT, the likelihood that pelvic nodes will be found earlier and more frequently. Unfortunately, The optimal treatment for patients with cN1 still remains unclear. Androgen deprivation therapy (ADT) is the cornerstone of prostate cancer with pelvic lymph node metastasis. Some retrospective and database studies have shown that addition of local radiotherapy (RT) to ADT improve the treatment outcome. The 2022 NCCN guideline recommend RT combined with 2 to 3 years ADT in patients with initially diagnosed cN1 prostate cancer who have a life expectancy greater than 5 years.

All patients received whole pelvis and prostate region radiotherapy. The dose to metastatic LN was escalated using simultaneous integrated boost (SIB) technique.

All patients received whole pelvis and prostate region proton irradiation of 46 GyE in 23 fractionsfollowed by localized carbon ion irradiation of 32GyE in 8 fractions to the prostate region. The dose to metastatic LN was escalated using simultaneous integrated boost (SIB) technique. The dose was 60-62.1GyE in 23 fractions as much as dose constraints. All patients will be recommened receive 2-3 years endocrine therapy.

Treatment related acute toxicity assessed by Common Terminology Criteria for Adverse Events (CTCAE) version 4.03

Inclusion Criteria: Histologically proven initial diagnosis of adenocarcinoma of the prostate; Clinical stage T1-4 N0 M0; Prostatic assessment by multiparametric (mp) MRI; Pelvic lymph node was assessed by PSMA PET/CT and mpMRI; No distant metastasis was proven by PSMA PET/CT; Patients may received neoadjuvant hormonal therapy; 45≤ Age ≤85; Adequate performance status (ECOG 0-1); No previous pelvic radiation therapy (RT); No previous prostatectomy; No previous invasive cancer (within 5 years before the prostate cancer diagnosis); Ability to understand character and individual consequences of the clinical trial; Written informed consent; Exclusion Criteria: No pathologically confirmed adenocarcinoma of the prostate; Distant metastasis (M1); Previous pelvic radiotherapy; Previous prostatectomy;