Clinical application of radiotherapy in patients with oligometastatic ovarian cancer: a sharp tool to prolong the interval of systemic treatment

Abstract

Background With the advances of radiation technology, treatment of oligometastatic disease, with limited metastatic burden, have more chances to achieve long-term local control. Here we aim to evaluate the efficacy and safety of radiotherapy (RT) in oligometastatic ovarian cancer patients. Methods A retrospective analysis collecting 142 patients (189 lesions) with oligometastatic ovarian cancer were included in the study. All pateints received radiotherapy and the curative effect and response rate were evaluated by diagnostic imaging after 1–3 months of radiotherapy with RECIST. Endpoints were the rate of complete response (CR), chemotherapy-free interval (CFI), local control (LC) rate and overall survival (OS) rate. Toxicity was evaluated by the Radiation Therapy Oncology Group (RTOG). Logistic and Cox regression were used for the uni- and multivariate analysis of factors influencing survival outcomes. Results From 2013.1.1 to 2020.12.30, a total of 142 ovarian cancer patients (189 oligometastasis lesions) were included in the analysis. Prescribed doses to an average GTV of 3.10 cm were 1.8–8 Gy/fraction, median BED (28–115, a/b = 10 Gy), 5–28 fractions. For 179 evaluable lesions, the cases of CR, partial response (PR), stable disease (SD) and progressive disease (PD) after radiotherapy were 22,39,38 and 80 respectively. The disease control rate (DCR): CR + PR + SD was 55.31%, and the objective response rate (ORR): CR + PR was 34.08%. No patient developed grade 3 or higher side effect. The median CFI was 14 months (1–99 months), and the LC rate was 69.7%, 54.3% and 40.9% in 1 year, 2 years and 5 years respectively. GTV < 3 cm before treatment, platinum sensitivity, time from the last treatment ≥ 6 months, single lesion and BED(a/b = 10 Gy) ≥ 60 are the factors of good LC (p < 0.05). The total OS of 1 year, 2 years and 5 years were 67.1%, 52.6% and 30.3%, respectively. Single lesion (HR 0.598, 95%CI 0.405–0.884), DCR (HR 0.640, 95% CI 0.448–0.918) and ORR(HR 0.466, 95% CI 0.308–0.707) were the significant factors influencing 5-year OS. Conclusion For patients with oligometastatic ovarian cancer, radiotherapy has high LC, long chemotherapy-free interval, and survival benefits. Subgroup analysis shows that patients with single lesion and good local treatment results have higher overall survival rate, suggesting that active treatment is also beneficial for oligometastatic ovarian cancer patients.

Is Prophylactic Radiotherapy to the Lymphatic Drainage Area Necessary for Patients With Stage III Ovarian Cancer After Chemotherapy Following Surgery?

“… 8 , 20 - 22 The past decade witnessed the development of IMRT, which could increase target dose and cause limited adverse effect at the same time. 14 - 16 , 23 We have proved that the preventive RT to abdominal and pelvic lymphatic drainage area instead of WART could be used as an alternative. Because the radiation range was narrowed, doses to normal organs were much lower, and related toxicity was thus minor.…”

Oligo-Metastatic Cancers: Putative Biomarkers, Emerging Challenges and New Perspectives

“…The incidence of OMD varies depending on the type of tumors. It was hypothesized in the past that some cancers such as pancreatic adenocarcinoma and small-cell lung cancer, never present with an oligo-metastatic behavior; to date, an oligo-metastatic status has been reported in all cancers [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. The incidence of OMD varies greatly among cancer types, ranging from extremely rape (such as SCLC where only a few case reports are described) [ 21 ] to 10–40% of HCC [ 25 , 26 ].…”

Stereotactic Body Radiation Therapy in Gynecologic Oligometastases: An Effective but Underutilized Approach

“…Hypofractionated regimens have been shown to modulate the tumor vasculature, potentially overcoming the negative effects of tissue hypoxia on radiation response. SBRT can induce a strong abscopal effect, wherein local radiation therapy results in the regression of distant, non-irradiated tumor sites through systemic immune activation [ 40 , 41 , 42 , 43 , 44 ].…”