ABSTRACT
Context: Tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) play an indispensable role in the treatment of non-small cell lung cancer (NSCLC), leading to a survival major breakthrough, but there remains no uniform standard for predicting the efficacy of TKI therapy. Aims: We retrospectively reviewed the use of EGFR-TKIs for advanced NSCLC between January 2009 and December 2017 in a hospital, which 169 patients who treated with first-line TKIs were enrolled. Subjects and Methods: Multiple clinical factors, including histology, age, and sex, were analyzed. We calculated the tumor shrinkage rate (TSR) by measuring the longest diameters of the main mass by computed tomography (CT) before TKI therapy and the first CT after TKI therapy. We evaluated overall survival (OS) and progression-free survival (PFS) after first-line TKI therapy, and we assessed factors predicting survival using the Kaplan–Meier method. Results: Eligible patients were sorted into higher (n = 83) and lower (n = 86) TSR groups according to the mean TSR of 0.49%. The 83 patients with a higher TSR had longer PFS and OS than those in the 86 patients with a lower TSR (14.83 vs. 8.40 months, P < 0.001, and 31.03 vs. 20.10 months, P < 0.001, respectively). Multivariate analyses revealed that TSR was an independent predictor of PFS and OS (PFS hazard ratio [HR]: 0.506, P < 0.001, and OS HR: 0.291, P < 0.001). Conclusions: These cumulative data support that TSR may be an early predictor of the treatment efficacy in NSCLC with EGFR mutations treated with first-line TKIs
ABSTRACT
Objective To study the dosimetric effect of two source patterns, including equal spacing and peripheral dense intermediate sparse by assuming a tumor shrinking speed of 20%per month after 125 I seed implantation. Methods A virtual cylindrical tumor with 4 cm in height and 5 cm in diameter was contoured on a three-dimensional treatment planning system ( TPS ) . Two groups of preoperative plans were made with 1. 85 × 107 Bq 125 I seeds using two source patterns respectively. It was assumed that the tumor height was unchanged, while the diameter of tumor would decrease at a speed of 20%per month, and the locations of seeds would concentrate towards the tumor core. The 90%target volume dose ( D90 ) , the ratio of 90%isodose volume over the target volume ( V90 ) , and the ratio of 150%isodose volume over the target volume (V150) were calculated at 0, 1, 2, 3 months after 125I implantation respectively. Results In equal spacing group, 85 seeds were implanted. The values of D90 were 126. 20, 130. 41, 133. 82 and 139. 48 Gy after 0, 1, 2 and 3 months respectively. The values of V90 were 97. 0%, 98. 1%, 99. 3%and 100%, while those of V150 were 70. 2%, 69. 9%, 71. 1% and 71. 5%. The dense in-periphery and sparse-in the middle group was loaded with 75 seeds. The D90 values were 126. 46, 125. 41, 123. 50 and 128. 83 Gy, the V9095. 2%, 95. 7%, 94. 9%and 97. 6%, and the V15052. 8%, 60. 4%, 62. 7%and 59. 3%after 0, 1, 2 and 3 months, respectiviely. Conclusions When the tumor diameter reduces at a rate of 20%per month after 125 I seed implantation, the expected tumor dose absorption will gradually increase using the equal spacing sources pattern. However, the expected dose does not vary withsource distribution of dense-in the-surrounding and sparse-in-middle, which also reduces high dose volume more than the equal spacing pattern.
ABSTRACT
Objective To study the dosimetric effect of two source patterns, including equal spacing and peripheral dense intermediate sparse by assuming a tumor shrinking speed of 20%per month after 125 I seed implantation. Methods A virtual cylindrical tumor with 4 cm in height and 5 cm in diameter was contoured on a three-dimensional treatment planning system ( TPS ) . Two groups of preoperative plans were made with 1. 85 × 107 Bq 125 I seeds using two source patterns respectively. It was assumed that the tumor height was unchanged, while the diameter of tumor would decrease at a speed of 20%per month, and the locations of seeds would concentrate towards the tumor core. The 90%target volume dose ( D90 ) , the ratio of 90%isodose volume over the target volume ( V90 ) , and the ratio of 150%isodose volume over the target volume (V150) were calculated at 0, 1, 2, 3 months after 125I implantation respectively. Results In equal spacing group, 85 seeds were implanted. The values of D90 were 126. 20, 130. 41, 133. 82 and 139. 48 Gy after 0, 1, 2 and 3 months respectively. The values of V90 were 97. 0%, 98. 1%, 99. 3%and 100%, while those of V150 were 70. 2%, 69. 9%, 71. 1% and 71. 5%. The dense in-periphery and sparse-in the middle group was loaded with 75 seeds. The D90 values were 126. 46, 125. 41, 123. 50 and 128. 83 Gy, the V9095. 2%, 95. 7%, 94. 9%and 97. 6%, and the V15052. 8%, 60. 4%, 62. 7%and 59. 3%after 0, 1, 2 and 3 months, respectiviely. Conclusions When the tumor diameter reduces at a rate of 20%per month after 125 I seed implantation, the expected tumor dose absorption will gradually increase using the equal spacing sources pattern. However, the expected dose does not vary withsource distribution of dense-in the-surrounding and sparse-in-middle, which also reduces high dose volume more than the equal spacing pattern.
ABSTRACT
Early tumor shrinkage( ETS) is defined as the reduction rate of tumor volume evaluated in ear-ly treatment.In recent years,mutiple studies have demonstrated that ETS predicted tumor prognosis well,it can be used as an important predictor of prognosis.Finding a predictor in the early phase of treatment can optimize treat-ment regimens and ameliorate the prognosis of tumor.We summarize the research progress of the relationship be-tween ETS and prognosis.