Optimal Timing of Radiotherapy after Incomplete Transarterial Chemoembolization for Barcelona Clinic Liver Cancer Stage B Hepatocellular Carcinoma

변화경,김나리,성진실 연세대학교의과대학 2021 Yonsei medical journal Vol.62 No.5

Purpose: The optimal timing for radiotherapy (RT) after incomplete transarterial chemoembolization (TACE) remains unclear. This study investigated the optimal timing to initiate RT after incomplete TACE in patients with Barcelona Clinic Liver Cancerstage B hepatocellular carcinoma. Materials and Methods: This study included 116 lesions in 104 patients who were treated with RT after TACE between 2001 and2016. The time interval between the last TACE session and RT initiation was retrospectively analyzed. The optimal cut-off time intervalthat maximized the difference in local failure-free rates (LFFRs) was determined using maximally selected rank statistics. Results: The median time interval was 26 days (range: 2–165 days). At a median follow-up of 18 months (range: 3–160 months),the median overall survival was 18 months. The optimal cut-off time interval appeared to be 5 weeks; using this cut-off, 65 and 39patients were classified into early and late RT groups, respectively. Early RT group had a significantly poorer Child-Pugh class andhigher alpha-fetoprotein levels compared to late RT group. Other characteristics, including tumor size (7 cm vs. 6 cm; p=0.144),were not significantly different between the groups. The 1-year LFFR was significantly higher in the early RT group than in the lateRT group (94.6% vs. 70.8%; p=0.005). On multivariate analysis, early RT was identified as an independent predictor of favorablelocal failure-free survival (hazard ratio: 3.30, 95% confidence interval: 1.50–7.29; p=0.003). Conclusion: The optimal timing for administering RT after incomplete TACE is within 5 weeks. Early administration of RT is associatedwith better local control.

Physical and Biological Characteristics of Particle Therapy for Oncologists

변화경,한민철,양경미,김진성,유규상,금웅섭,김용배 대한암학회 2021 Cancer Research and Treatment Vol.53 No.3

Particle therapy is a promising and evolving modality of radiotherapy that can be used to treat tumors that are radioresistant to conventional photon beam radiotherapy. It has unique biological and physical advantages compared with conventional radiotherapy. The characteristic feature of particle therapy is the “Bragg peak,” a steep and localized peak of dose, that enables precise delivery of the radiation dose to the tumor while effectively sparing normal organs. Especially, the charged particles (e.g., proton, helium, carbon) cause a high rate of energy loss along the track, thereby leading to high biological effectiveness, which makes particle therapy attractive. Using this property, the particle beam induces more severe DNA double-strand breaks than the photon beam, which is less influenced by the oxygen level. This review describes the general biological and physical aspects of particle therapy for oncologists, including non-radiation oncologists and beginners in the field.

Role of Interleukin-7 in the Development of and Recovery from Radiation-Induced Lymphopenia: A Post-hoc Analysis of a Prospective Cohort

변화경,정승연,김경진,성진실 대한암학회 2021 Cancer Research and Treatment Vol.53 No.4

Purpose Radiation-induced lymphopenia is associated with worse outcomes in solid tumors. We assessed the impact of interleukin-7 (IL-7), a key cytokine in lymphocyte homeostasis, on radiation-induced lymphopenia. Materials and Methods A post-hoc analysis was performed in a prospective cohort of 98 patients with hepatocellular carcinoma who were treated with radiotherapy in 2016-2018. Blood IL-7 levels were assayed before and at the end of radiotherapy. Acute severe lymphopenia (ASL) was defined as a total lymphocyte count of < 200/μL during radiotherapy. Cox and logistic regression analyses were performed to identify predictors of survival and ASL development, respectively. Results Patients with ASL (n=41) had significantly poorer overall survival than those without (12.0 months vs. 25.3 months, p=0.001). Patients with lymphocyte recovery showed significantly longer overall survival than those without (21.8 months vs. 10.3 months, p=0.042). ASL was an independent predictor of poor survival (hazard ratio, 2.07; p=0.015). Patients with ASL had significantly lower pre-radiotherapy IL-7 levels (2.07 pg/mL vs. 3.01 pg/mL, p=0.010). A high pre-radiotherapy IL-7 level was an independent predictor of a reduced risk of ASL development (hazard ratio, 0.40; p=0.004). IL-7 levels reflected a feedback response to ASL, with a higher ΔIL-7 in patients with ASL and a lower ΔIL-7 in those without ASL (0.48 pg/mL vs. –0.66 pg/mL, p < 0.001). Post-radiotherapy IL-7 levels were significantly positively correlated with the total lymphocyte counts at 2 months. Conclusion IL-7 is associated with the development of and recovery from ASL, which may impact survival. To overcome radiation-induced lymphopenia, a novel strategy using IL-7 may be considered.

혈액선량에 따른 림프구 감소 양상 분석

김서한,변화경,이익재,성원모 대한방사선방어학회 2022 대한방사선방어학회 학술발표회 논문요약집 Vol.2022 No.11

The role of salvage radiotherapy in recurrent thymoma

양지훈,최서희,변화경,Hyun Ju Kim,이창걸,조재호 대한방사선종양학회 2019 Radiation Oncology Journal Vol.37 No.3

Purpose: To explore the role of salvage radiotherapy (RT) for recurrent thymoma as an alternative to surgery. Materials and Methods: Between 2007 and 2015, 47 patients who received salvage RT for recurrent thymoma at Yonsei Cancer Center were included in this study. Recurrent sites included initial tumor bed (n = 4), pleura (n = 19), lung parenchyma (n = 10), distant (n = 9), and multiple regions (n = 5). Three-dimensional conformal and intensity-modulated RT were used in 29 and 18 patients, respectively. Median prescribed dose to gross tumor was 52 Gy (range, 30 to 70 Gy), with equivalent doses in 2-Gy fractions (EQD2). We investigated overall survival (OS), progression-free survival (PFS), and patterns of failure. Local failure after salvage RT was defined as recurrence at the target volume receiving >50% of the prescription dose. Results: Median follow-up time was 83 months (range, 8 to 299 months). Five-year OS and PFS were 70% and 22%, respectively. The overall response rate was 97.9%; complete response, 34%; partial response, 44.7%; and stable disease, 19.1%. In multivariate analysis, histologic type and salvage RT dose (≥52 Gy, EQD2) were significantly associated with OS. The high dose group (≥52 Gy, EQD2) had significantly better outcomes than the low dose group (5-year OS: 80% vs. 59%, p = 0.046; 5-year PFS: 30% vs. 14%, p=0.002). Treatment failure occurred in 34 patients; out-of-field failure was dominant (intra-thoracic recurrence 35.3%; extrathoracic recurrence 11.8%), while local failure rate was 5.8%. Conclusion: Salvage RT for recurrent thymoma using high doses and advanced precision techniques produced favorable outcomes, providing evidence that recurrent thymoma is radiosensitive.

A novel gene signature associated with poor response to chemoradiotherapy in patients with locally advanced cervical cancer

김경환,장지석,변화경,김용배 대한부인종양학회 2022 Journal of Gynecologic Oncology Vol.33 No.1

Objective: We aimed to investigate the distinct transcriptional landscape in poor responders to concurrent chemoradiotherapy (CCRT) and to gain mechanistic insights into treatment resistance in cervical cancer. Methods: RNA sequencing was performed in patients with locally advanced cervical cancer treated with platinum-based CCRT. Transcriptome data of no durable benefit (NDB; progression-free period <3 years) and durable clinical benefit (DCB; progression-free period >5 years) patients were compared. The NDB score was estimated for each patient using differentially expressed genes between NDB and DCB patients. The potential response to programmed death-1 blockade was estimated using the tumor immune dysfunction and exclusion (TIDE) score and T-cell-inflamed gene expression profile (GEP). Results: NDB patients exhibited a distinct transcriptional profile compared to DCB patients, such as higher signatures of extracellular matrix organization and epithelial-to- mesenchymal transition. The fraction of cancer-associated fibroblasts (CAFs) within the tumor was significantly higher in NDB patients than in DCB patients. High NDB scores were significantly associated with poor survival in the Cancer Genome Atlas cervical cancer cohort (n=274; p=0.015) but only in patients who received curative aim radiotherapy (p=0.002). Patients with high NDB scores displayed significantly higher TIDE prediction scores and lower T-cell-inflamed GEP scores than those with low NDB scores. Conclusion: Patients with cervical cancer having poor CCRT or RT outcomes exhibited a distinct gene signature that could predict treatment outcomes. For poor responders, immune checkpoint inhibitors may be less effective whereas CAF-targeting treatments may be a promising approach.

비정형 수막종 환자에서 예후 예측 모델링을 통한 보조 방사선치료의 생존이점 분석

김예슬,김도욱,성원모,변화경,장원익,이주호,조재호,김인아,Clemens Grassberger,위찬우,윤홍인 대한방사선방어학회 2023 대한방사선방어학회 학술발표회 논문요약집 Vol.2023 No.04