Study on Triple Therapy Combined With HIFU for High-Tumor-Burden mHSPC

Inclusion Criteria:

1. Patients who agree to participate in the study and sign the informed consent form.
2. Age ≥18 years, male.
3. Histologically or cytologically confirmed prostate adenocarcinoma.
4. Bone scan, CT, or MRI showing ≥4 bone metastases (with ≥1 outside the pelvis or spine) or visceral metastases.
5. Newly diagnosed or recurrent disease after local therapy, with sensitivity to androgen deprivation therapy (ADT).
6. Patients who have received ADT (medical or surgical castration) with or without first-generation antiandrogens for ≤3 months, without evidence of soft tissue disease progression (per RECIST 1.1) or clinically significant PSA progression (≥50% increase from nadir with serum testosterone at castrate levels).
7. Planned treatment with docetaxel plus apalutamide and ADT, or apalutamide plus ADT.
8. ECOG Performance Status (PS) score of 0-1.
9. Adequate hematologic and organ function:

   * \*\*Bone marrow function (without transfusion or growth factor support):\*\*
   * Absolute neutrophil count (ANC) ≥1.5 × 10⁹/L (1500/μL)
   * Hemoglobin ≥90 g/L (9.0 g/dL)
   * Platelet count ≥100 × 10⁹/L (100,000/μL)
   * \*\*Liver function:\*\*
   * Total bilirubin (TBIL) ≤1.5 × ULN
   * AST, ALT, and alkaline phosphatase (ALP) ≤2.5 × ULN
   * \*\*Renal function:\*\*
   * Serum creatinine ≤1.5 × ULN \*\*or\*\* calculated creatinine clearance ≥30 mL/min (Cockcroft-Gault formula)
   * \*\*Coagulation function (without anticoagulation therapy):\*\* INR ≤1.5
10. Patients of reproductive potential must use effective contraception during the study and for 6 months after the last dose.

Exclusion Criteria:

1. Lesions located at the prostate apex or in areas inaccessible for focal therapy.
2. Beaded prostatic calculi or cysts \>1 cm in diameter within the treatment or ultrasound pathway.
3. Urethral stricture or presence of metal/other implants in the urethra.
4. Prior rectal surgery.
5. History of or existing rectal fistula.
6. Rectal stenosis preventing transrectal ultrasound.
7. Rectal invasion.
8. Active severe urinary tract infection.
9. Severe cardiovascular or cerebrovascular disease affecting anesthesia/surgery.
10. History of hypersensitivity or intolerance to any study drugs.
11. Planned concurrent anticancer therapy during the study.
12. Prior treatment with second-generation androgen receptor (AR) inhibitors (e.g., apalutamide, enzalutamide, darolutamide), CYP17 inhibitors (e.g., abiraterone acetate, ketoconazole), chemotherapy, immunotherapy, or adjuvant/neoadjuvant therapy.
13. Use of herbal products with anti-prostate cancer or PSA-lowering effects (e.g., saw palmetto) within 4 weeks before study treatment.
14. History of seizures, medications that lower seizure threshold, or conditions predisposing to seizures within 12 months (including TIA, stroke, or traumatic brain injury with hospitalization).
15. Active cardiac disease within 6 months before treatment: severe/unstable angina, myocardial infarction, congestive heart failure (NYHA Class III/IV), or arrhythmia requiring medication.
16. Conditions impairing drug absorption (e.g., dysphagia, chronic diarrhea, intestinal obstruction).
17. Immunodeficiency (e.g., HIV-positive, congenital/acquired immunodeficiency) or organ transplant history.
18. Known brain metastases.
19. Other malignancies within 5 years (except cured basal cell carcinoma or cervical carcinoma in situ).
20. Concurrent participation in another investigational drug/device trial.
21. Poor compliance likely to hinder treatment/follow-up.
22. Uncontrolled comorbidities (e.g., hypertension, diabetes, neuropsychiatric disorders) that may compromise safety or confound results, per investigator judgment.
23. Any other condition deemed unsuitable for inclusion by the investigator.