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Cheng T, Peng R, Qu A, Wang H. High-dose rate endorectal brachytherapy for rectal cancer: A state-of-the-art review. Cancer Sci 2023; 114:4145-4156. [PMID: 37702196 PMCID: PMC10637059 DOI: 10.1111/cas.15959] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/17/2023] [Accepted: 08/28/2023] [Indexed: 09/14/2023] Open
Abstract
Rectal cancer is a common malignancy that requires multidisciplinary treatment. By utilizing the dose-response relationship in rectal cancer radiotherapy, increasing the radiotherapy dose can improve clinical complete remission rates. High-dose rate endorectal brachytherapy (HDREBT) is a novel technique that delivers high doses of radiotherapy directly to the tumor via an endorectal applicator, sparing the adjacent normal tissues from excessive radiation exposure. HDREBT includes contact X-ray brachytherapy and high-dose-rate intracavitary brachytherapy. We introduce the latest developments in applicators and imaging techniques for HDREBT in rectal cancer and summarize the current evidence on the efficacy, safety, and feasibility of HDREBT as a neoadjuvant, definitive, or palliative treatment option for all stages of rectal cancer patients. We also discuss the potential advantages and challenges of HDREBT in achieving organ preservation and improving the quality of life of rectal cancer patients. HDREBT has shown promising results in achieving high complete response rates, enabling nonoperative management, improving organ preservation rates, and providing effective palliation in rectal cancer patients. More studies are needed to optimize its dose and fractionation schemes in different clinical scenarios.
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Affiliation(s)
- Tian Cheng
- Cancer CenterPeking University 3rd HospitalBeijingChina
- Peking University Health Science CenterPeking UniversityBeijingChina
| | - Ran Peng
- Department of Radiation OncologyPeking University 3rd HospitalBeijingChina
| | - Ang Qu
- Department of Radiation OncologyPeking University 3rd HospitalBeijingChina
| | - Hao Wang
- Cancer CenterPeking University 3rd HospitalBeijingChina
- Department of Radiation OncologyPeking University 3rd HospitalBeijingChina
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Lee CY, Kaza E, Harris TC, O'Farrell DA, King MT, Dyer MA, Cormack RA, Buzurovic I. Catheter reconstruction and dosimetric verification of MRI-only treatment planning (MRTP) for interstitial HDR brachytherapy using PETRA sequence. Phys Med Biol 2023; 68. [PMID: 36584396 DOI: 10.1088/1361-6560/acaf48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 12/30/2022] [Indexed: 12/31/2022]
Abstract
Objective. The feasibility of MRI-only treatment planning (MRTP) for interstitial high-dose rate (HDR) brachytherapy (BT) was investigated for patients diagnosed with gynecologic cancer.Approach. A clinical MRTP workflow utilizing a 'pointwise encoding time reduction with radial acquisition (PETRA)' sequence was proposed. This is a clinically available MRI sequence optimized to improve interstitial catheter-tissue contrast. Interstitial needles outside the obturator region were reconstructed using MR images only. For catheters penetrating through the obturator, a library-based reconstruction was proposed. In this work, dwell coordinates from the clinical CT-based reconstruction were used as the surrogate for the library-based approach. For MR-only plan, dwell times were activated and assigned as in the clinical plans. The catheter reconstruction was assessed by comparing dwell position coordinates. The dosimetric comparisons between a clinical plan and MR-only plan were assessed for physical and EQD2 dose and volume parameters forD90,D50andD98for clinical target volume (CTV) andD2cc,D0.1ccandD5ccfor OARs.Main results. Catheter reconstruction was possible using the optimized PETRA sequence on MR images. An overall reconstruction difference of 1.7 ± 0.5 mm, attributed to registration-based errors, was found compared to the CT-based reconstruction. The MRTP workflow has the potential to generate a treatment plan with an equivalent dosimetric quality compared to the conventional CT/MRI-based approach. For CTVD90, physical and EQD2 dose and volume parameter differences were 1.5 ± 1.9% and 0.7 ± 1.0 Gy, respectively. ForD2ccOARs, DVH (EQD2) differences were -0.4 ± 1.1% (-0.2 ± 0.5 Gy), 0.5 ± 2.8% (0.2 ± 1.3 Gy) and -0.5 ± 1.4% (-0.2 ± 0.5 Gy) for rectum, bladder, and sigmoid, respectively.Significance. With the proposed MRTP approach, CT imaging may no longer be needed in HDR BT for interstitial gynecologic treatment. A proof-of-concept study was conducted to demonstrated that MRTP using PETRA is feasible, with comparable dosimetric results to the conventional CT/MRI-based approach.
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Affiliation(s)
- Casey Y Lee
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
| | - Evangelia Kaza
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
| | - Thomas C Harris
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
| | - Desmond A O'Farrell
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
| | - Martin T King
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
| | - Michael A Dyer
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
| | - Robert A Cormack
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
| | - Ivan Buzurovic
- Department of Radiation Oncology, Dana-Farber/Brigham and Women's Hospital, Harvard Medical School, Boston, United States of America
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Kaza E, Lee CY, King MT, Dyer MA, Cormack RA, Buzurovic I. First pointwise encoding time reduction with radial acquisition (PETRA) implementation for catheter detection in interstitial high-dose-rate (HDR) brachytherapy. Brachytherapy 2022; 21:501-510. [PMID: 35337748 DOI: 10.1016/j.brachy.2022.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 12/15/2021] [Accepted: 01/15/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE A pointwise encoding time reduction with radial acquisition (PETRA) sequence was optimized to detect empty catheters in interstitial (HDR) brachytherapy with clinically acceptable spatial accuracy for the first time. Image quality and catheter detectability were assessed in phantoms, and the feasibility of PETRA's clinical implementation was assessed on a gynecological cancer patient. METHODS AND RESULTS Empty catheters embedded in a gelatin phantom displayed positive signal on PETRA and more accurate cross-sections than on clinically employed T2-weighted sequences, differing by 0.4 mm on average from their nominal 2 mm diameter. PETRA presented minimal susceptibility differences and a symmetric metal artifact, contrary to the clinical sequences. The PETRA-CT catheter tip position differences assessed by a treatment planning system (TPS) were < 1 mm. PETRA also detected an interstitial template with empty catheters penetrating a poultry phantom and fused very well with CT. Interstitial catheter positional difference between PETRA and CT images was < 1 mm on average, increasing with distance from isocenter. All interstitial catheters and the employed interstitial template were detected on PETRA images of an endometrial adenocarcinoma patient. Empty needles were traceable using a TPS, with higher spatial resolution and more favorable contrast than on T2-weighted images used for contouring. A treatment plan could be produced by combining information from PETRA for catheter detection and from T2-weighted images for tumor and organs delineation. CONCLUSIONS PETRA detected successfully and accurately interstitial catheters in phantoms. Its first clinical implementation shows a potential for MR-only treatment planning in interstitial HDR brachytherapy.
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Affiliation(s)
- Evangelia Kaza
- Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA.
| | - Casey Y Lee
- Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
| | - Martin T King
- Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
| | - Michael A Dyer
- Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
| | - Robert A Cormack
- Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
| | - Ivan Buzurovic
- Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
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