3D-printed Biodegradable Breast Implants for Breast Restoration

A Prospective, Multicenter, Controlled Clinical Study of 3D-printed Biodegradable Breast Implants for Breast Restoration

The purpose of this clinical trial is to evaluate the cosmetic effect of breast reconstruction based on 3D-printed biodegradable material breast implants in personalized breast reconstruction and the quality of life of patients, with traditional breast-conserving surgery and traditional breast reconstruction as controls. It will also explore the safety of breast reconstruction based on 3D-printed biodegradable material breast implants in personalized breast reconstruction. The main question it aims to answer is:

Can breast cancer patients who are not suitable for breast-conserving surgery use 3D-printed biodegradable material breast implants for breast reconstruction? Do patients who undergo breast reconstruction based on 3D-printed biodegradable material breast implants have advantages over those who receive breast-conserving surgery or traditional silicone prosthesis breast reconstruction surgery in terms of cosmetic effects, quality of life and safety? What medical problems may occur when participants use 3D-printed biodegradable material-based breast implants for breast reconstruction?

Participants will:

Non-random enrollment. In the experimental group, breast reduction surgery based on 3D-printed degradable biological implants was received; In control group 1, traditional breast-conserving surgery was received; Traditional silicone prosthesis breast reconstruction was received in control Group 2.

This is a prospective, multicenter, controlled clinical study divided into three groups. The experimental group receives breast reconstruction using 3D-printed biodegradable material breast implants, while the control groups undergo traditional breast-conserving surgery or breast reconstruction with silicone implants.

After providing full informed consent, subjects voluntarily choose their surgical approach, sign the informed consent form, and enter the trial period after passing screening. The specific treatment protocols are as follows:

1. Preoperative Patient-Reported Outcome Assessment:

   The Chinese version of the BREAST-Q V2.0 scale is used to evaluate breast aesthetics, satisfaction, and quality of life, with calculation of the Q-score.

2. Imaging Assessment:

   Enrolled patients undergo preoperative thin-slice breast magnetic resonance imaging (MRI), including conventional plain scan (SE T1WI sequence) and 3D dynamic contrast-enhanced scanning (FLASH sequence) to obtain three-dimensional enhanced images.

3. Surgical Simulation, Design, and 3D Printing of Fillers for the Experimental Group:

   Three-dimensional model data of the breast tissue to be resected are acquired via MRI scanning. The Mimics software is used to extract models of diseased and healthy tissues for surgical planning. Subsequently, Geomagic and 3-matic software are employed to design the breast filler model, which is optimized for mechanical properties, cell ingrowth conditions, and degradation time requirements. Finally, the breast implant model is layer-by-layer printed using polycaprolactone (PCL) as the material via selective laser sintering (SLS) technology, followed by sterilization for standby use.

4. Surgery:

   Experimental Group: Tumors are resected through transverse arc, periareolar, or radial incisions to ensure negative margins, followed by axillary lymph node dissection or sentinel lymph node biopsy. The 3D-printed filler is then implanted and sutured in place.

   Control Groups: Conventional breast-conserving surgery or nipple-areola-preserving subcutaneous gland resection combined with simultaneous breast reconstruction using implants is performed according to clinical routines. Incision types are selected by the surgeon. Tissue behind the nipple is sent for intraoperative pathological examination, and patch application is decided as needed.

5. Postoperative Managemen:

   Wound dressing changes are performed on schedule, and the occurrence of complications or adverse reactions (e.g., infection) is recorded.

6. Postoperative Systemic Therapy:

   Systemic chemotherapy or endocrine therapy is administered according to standard protocols. All patients in the experimental group receive local radiotherapy following the regimen for conventional breast-conserving surgery, including boost irradiation to the tumor bed. Radiotherapy for the control groups is decided according to current clinical guidelines and specifications.

7. Postoperative Follow-Up Imaging and Assessments:

   Ultrasound Examinations: Routine breast ultrasound is conducted weekly within the first postoperative month, then monthly thereafter, to record changes in blood supply in the filler area. Full-volume breast ultrasound is performed every 3 months.

   MRI Examinations and PRO Assessments: MRI is conducted at 3, 6, 12, and 24 months postoperatively. Concurrently, the Chinese version of the BREAST-Q V2.0 scale is used to evaluate breast aesthetics, satisfaction, and quality of life, with calculation of the Q-score.

8. Database Follow-Up:

Telephone follow-ups are conducted once monthly, and in-person follow-ups are conducted once every 3 months.

Inclusion Criteria:

• Female patients with newly diagnosed primary breast cancer, aged 18 to 70 years, confirmed by histopathology.
• Willing to undergo breast-conserving surgery, concurrent silicone prosthesis breast reconstruction, or breast reconstruction with 3D-printed biodegradable material breast implants.
• Having indications for subcutaneous glandectomy that preserves the nipples and areolas.
• ECOG performance status score: 0-1.
• If receiving neoadjuvant chemotherapy, the interval between chemotherapy completion and surgery is less than 8 weeks.
• Good compliance with the planned treatment, ability to understand the study procedures, and willingness to sign the written informed consent form.

Exclusion Criteria:

• Age > 70 years.
• Newly diagnosed stage IV metastatic breast cancer.
• Multicentric, extensive, or diffuse lesions; or inflammatory breast cancer.
• Tumor invasion of the papillary areola complex.
• Inability to accept/tolerate radiotherapy.
• Breast cancer during pregnancy.
• History of other malignant tumors within the past five years (except cured cervical carcinoma in situ and non-melanoma skin cancer).
• Abnormal functions of vital organs (heart, lungs, liver, kidneys), poorly controlled diabetes, or other conditions that preclude surgery tolerance.
• Patients deemed unsuitable for participation by the researchers.