{
    "abstract": "Stereotactic radiotherapy (SRT) has been widely used for the treatment of brain metastases and early stage non-small-cell lung cancer (NSCLC). Excellent SRT plans are characterized by steep dose fall-off, making it critical to accurately and comprehensively predict and evaluate dose fall-off.\nA novel dose fall-off index was proposed to ensure high-quality SRT planning.\nThe novel gradient index (NGI) had two different modes: NGIx V for three-dimensions and NGIx r for one-dimension. NGIx V and NGIx r were defined as the ratios of the decreased percentage dose (x%) to the corresponding isodose volume and equivalent sphere radii, respectively. A total of 243 SRT plans at our institution between April 2020 and March 2022 were enrolled, including 126 brain and 117 lung SRT plans. Measurement-based verifications were performed using SRS MapCHECK. Ten plan complexity indexes were calculated. Dosimetric parameters related to radiation injuries were also extracted, including the normal brain volume exposed to 12\u00a0Gy (V\nThere were statistically significant correlations between NGI and PTV size (r\u00a0=\u00a0-0.98, P\u00a0<\u00a00.01 for NGI50 V and r\u00a0=\u00a0-0.93, P\u00a0<\u00a00.01 for NGI50 r), which were the strongest correlations compared with GI (r\u00a0=\u00a00.11, P\u00a0=\u00a00.13), R\nCompared with GI, R",
    "authors": [
        {
            "affiliation": "Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China.",
            "firstname": "Zhengwen",
            "initials": "Z",
            "lastname": "Shen"
        },
        {
            "affiliation": "Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China.",
            "firstname": "Huanli",
            "initials": "H",
            "lastname": "Luo"
        },
        {
            "affiliation": "Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China.",
            "firstname": "Shi",
            "initials": "S",
            "lastname": "Li"
        },
        {
            "affiliation": "Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China.",
            "firstname": "Xia",
            "initials": "X",
            "lastname": "Tan"
        },
        {
            "affiliation": "Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China.",
            "firstname": "Xiumei",
            "initials": "X",
            "lastname": "Tian"
        },
        {
            "affiliation": "Department of Oncology, Chongqing University Three Gorges Hospital, Chongqing, China.",
            "firstname": "Qiang",
            "initials": "Q",
            "lastname": "Liu"
        },
        {
            "affiliation": "Department of Radiation Oncology, Chongqing University Cancer Hospital, Chongqing, China.",
            "firstname": "Fu",
            "initials": "F",
            "lastname": "Jin"
        }
    ],
    "conclusions": null,
    "copyrights": "\u00a9 2023 The Authors. Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.",
    "doi": "10.1002/mp.16383",
    "journal": "Medical physics",
    "keywords": [
        "dose fall-off",
        "novel gradient index",
        "plan complexity",
        "radiation injuries",
        "stereotactic radiotherapy"
    ],
    "methods": null,
    "publication_date": "2023-03-25",
    "pubmed_id": "36960718",
    "results": "There were statistically significant correlations between NGI and PTV size (r\u00a0=\u00a0-0.98, P\u00a0<\u00a00.01 for NGI50 V and r\u00a0=\u00a0-0.93, P\u00a0<\u00a00.01 for NGI50 r), which were the strongest correlations compared with GI (r\u00a0=\u00a00.11, P\u00a0=\u00a00.13), R",
    "title": "A novel dose fall-off index and preliminary application in brain and lung stereotactic radiotherapy.",
    "xml": "<Element 'PubmedArticle' at 0x7885028c1030>"
}