A graded prognostic model for patients surviving 3 years or more (GPM ≥ 3Ys) after stereotactic radiosurgery for brain metastasis. (March 2021)

• Record Type: Journal Article
• Authors: Sato, Yasunori; Yamamoto, Masaaki; Serizawa, Toru; Yamada, Kei-ichiro; Higuchi, Yoshinori; Kasuya, Hidetoshi
• Is Part Of: Radiotherapy and oncology. Volume 156(2021)
• Page Start: 29
• Page End: 35
• Publication Date: 2021-03
• Subjects: Brain metastases -- Prognosis -- Grading system -- Radiation therapy -- Radiosurgery -- Gamma knife; Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2020.11.024
• Languages: English
• ISSNs: 0167-8140

Abstract

Highlights: Due to recent advances in treatments, increasing numbers of brain metastasis (BM) patients have been surviving longer. Using the second author's dataset of 3237 radiosurgically-treated BM patients, we developed a Graded Prognostic Model for Patients Surviving 3 Years or More (GPM ≥ 3Ys). Patients were categorized into the four grades according to the sum of scores. Median survival times (MSTs) differed significantly ( p < 0.0001) among the four GPM ≥ 3Ys grades. These results were validated using the third author's dataset including 3317 patients ( p < 0.0001). Abstract: Background and purpose: As more cancer patients with brain metastases (BMs) are surviving longer due to recent advancements in various treatment modalities, we developed a grading system for stereotactic radiosurgery (SRS)-treated BM patients with long survival. This is a Graded Prognostic Model for Patients Surviving 3 Years or More (GPM ≥ 3Ys). Materials and methods: First, using clinical factor-survival time analysis of 3237 patients in whom gamma knife (GK) SRS was performed by the second author (test cohort), we developed the GPM ≥ 3Ys based on survival ≥3 years as the objective variable. The validity of this model was then tested using another series of 3317 patients independently undergoing GK SRS performed by the third author (verification cohort). Number of patients surviving 3 years or more were 289 (8.9%) and 348 (10.5%), respectively. Results: Using the test series, among various pre-SRS clinical factors, noted below, five were shown to be highly correlated with survival of ≥3 years. Therefore, we assigned scores for these five factors, i.e., "tumor numbers 1/2–4/≥5 (score; 6/1/0)", "female/male (5/0)", "KPS ≥80%/<80% (5/0)", "primary cancers of breast/lung/gastrointestinal tract/other (score; 1/0/3/0)", "controlled primary cancer/not (8/0)" and "existing extra-cerebral metastases/not (5/0). Patients were categorized into four grades according to the sum of scores, i.e., 0–9, 10–19, 20–29 and 30–36. Post-SRS mean survival times (MSTs) differed significantly ( p < 0.0001) with no overlapping of 95% confidence intervals (CIs) among the four grades. Also, in the verification series, MSTs differed significantly ( p < 0.0001) with no overlapping of 95% CI among the four grades of the GPM ≥ 3Ys system. Conclusion: Although this was a retrospective study, the GPM ≥ 3Ys system was shown to be very useful to physicians selecting among more aggressive treatment modalities for patients in whom longer survival can be expected.