Abstract:
Purpose: Stereotactic body radiotherapy (SBRT) has been increasingly used for liver metastases which are unresectable or not suitable for other local therapy. Although burgeoning literature has been discussing SBRT for liver metastases, most SBRT to liver metastases requires fiducial markers and/or air-breath control for organ motion management. These methods are invasive with more complication, limited to favorable patients, and demand more training for both physicians and therapists. Therefore, we report our experience about the outcome and toxicity of SBRT for liver metastases, using respiration correlated CT (4D-CT) and abdominal compressor as organ motion management.
Materials and Methods: Between 2009 June to 2017 December, 27 patients with 39 hepatic nodules at our institution, after multidisciplinary review, received SBRT to their liver metastases, which were not suggested for other local therapy, including resection. Mean diameter for each nodule was 2.37 cm (range: 0.6 ~ 6.0cm) and mean gross tumor volume (GTV) was 22.70ml (range: 3.85 ~ 107.7ml). Prescribed dose ranges 21 to 42Gy in 3 to 6 fractions with 5-7Gy per fraction.
Results: None of these 27 patients developed ≥grade 3 side effects during or within 1 month after radiotherapy. For 25, traceable and assessable patients, median follow-up was 14.3 months (range: 3~26 months). Despite all patients continued chemotherapy, 4 patients achieved complete remission (CR) after SBRT while 10 patients had partial response (PR) and 8 patients remained stable disease (SD). In-field progression-free survival (in-field defines as irradiation area) for CR, PR and SD patients were 15.9, 6.9 and 6.4 months while overall survival were 15.9, 18.2 and 8.3 months, respectively.
Conclusion: For liver metastases not indicated for operation nor other local therapy, SBRT offers a feasible option for considerable local tumor control. Although our domestic practice was relatively more conservative, this initial singleinstitute experience might help provide an option for future liver metastases.
