title: A Novel Form of Breast Intraoperative Radiation Therapy With CT-Guided High-Dose-Rate Brachytherapy: Results of a Prospective Phase 1 Clinical Trial.
abstract: Existing intraoperative radiation therapy (IORT) techniques are criticized for the lack of image guided treatment planning and energy deposition with, at times, poor resultant dosimetry and low radiation dose. We pioneered a novel method of IORT that incorporates customized, computed tomography (CT)-based treatment planning and high-dose-rate (HDR) brachytherapy to overcome these drawbacks: CT-HDR-IORT.
  
  
  
  A phase 1 study was conducted to demonstrate the feasibility and safety of CT-HDR-IORT. Eligibility criteria included age ≥50 years, invasive or in situ breast cancer, tumor size <3 cm, and N0 disease. Patients were eligible before or within 30 days of breast-conserving surgery (BCS). BCS was performed, and a multilumen balloon catheter was placed. CT images were obtained, a customized HDR brachytherapy plan was created, and a dose of 12.5 Gy was delivered to 1-cm depth from the balloon surface. The catheter was removed, and the skin was closed. The primary endpoints were feasibility and acute toxicity. Feasibility was defined as IORT treatment interval (time from CT acquisition until IORT completion) ≤90 minutes. The secondary endpoints included dosimetry, cosmetic outcome, quality of life, and late toxicity.
  
  
  
  Twenty-eight patients were enrolled. The 6-month follow-up assessments were completed by 93% of enrollees. The median IORT treatment interval was 67.2 minutes (range, 50-108 minutes). The treatment met feasibility criteria in 26 women (93%). The dosimetric goals were met in 22 patients (79%). There were no Radiation Therapy Oncology Group grade 3+ toxicities; 6 patients (21%) experienced grade 2 events. Most patients (93%) had good/excellent cosmetic outcomes at the last follow-up visit.
  
  
  
  CT-HDR-IORT is feasible and safe. This promising approach for a conformal, image-based, higher-dose breast IORT is being evaluated in a phase 2 trial.
authors: Division of Surgical Oncology, Department of Surgery, University of Virginia School of Medicine, Charlottesville, Virginia. Electronic address: snl2t@virginia.edu.
authors: Shayna L
authors: SL
authors: Showalter
authors: Division of Translation Research and Applied Statistics, Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Gina
authors: G
authors: Petroni
authors: Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Daniel M
authors: DM
authors: Trifiletti
authors: Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Bruce
authors: B
authors: Libby
authors: Division of Surgical Oncology, Department of Surgery, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Anneke T
authors: AT
authors: Schroen
authors: Division of Surgical Oncology, Department of Surgery, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: David R
authors: DR
authors: Brenin
authors: Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Parchayi
authors: P
authors: Dalal
authors: Division of Translation Research and Applied Statistics, Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Mark
authors: M
authors: Smolkin
authors: Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Kelli A
authors: KA
authors: Reardon
authors: Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, Virginia.
authors: Timothy N
authors: TN
authors: Showalter
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D003131:Combined Modality Therapy / Q000009:adverse effects / Q000379:methods; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008408:Mastectomy / Q000379:methods*; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control; D011879:Radiotherapy Dosage; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome