Stereotactic Body Radiation Therapy for Liver Metastases: Single Institution Experience

Abstract

Background: Stereotactic body radiation therapy (SBRT) is an emerging local treatment for limited liver metastases. We report a single institution experience with liver metastases treated with SBRT. Methods: Twenty-three consecutive patients treated with SBRT for 27 liver metastases: eight women and 15 men, median age 69 years (26 to 87). SBRT was the chosen therapy when the disease was considered life-limiting and unsuitable for resection or radio-frequency ablation. The median radiation dose was 40 Gy (20 to 50 Gy) delivered in one to 10 fractions. Response to treatment was measured according to RECIST criteria on post-treatment CT, MRI and/or PET imaging. Acute and late toxicities were graded according to CTCAE v4.0. Results: Twenty-two patients completed SBRT. One stopped treatment after three fractions due to biliary obstruction from progressive tumor. Treatment was well-tolerated, with three patients (13.6%) presenting with Grade 1 and two (9%) presenting with Grade 2 acute gastrointestinal toxicity. Median follow-up was 15 months (range: 3-43) with one patient lost to follow-up. A single patient had symptomatic colitis that resolved with conservative treatment. Complete response was initially achieved in eight of 25 (32%) lesions, partial response in four (16%), disease stabilization in 12 (48%), and continued progression in one (4%). At last follow-up, six of 21 patients (28.6%) had progression of a treated lesion. Actuarial overall one-year and two-year survival rates were 94% and 60%, respectively (median 30.1 months). Actuarial one and two-year local control rates were 62%. Conclusions: SBRT is a promising well-tolerated treatment for non-resectable liver metastases.

Stereotactic Radiotherapy for Liver Metastases

“…Overall, the studies report local control rates ranging from 55-100 % at one to two years. [36][37][38][39][40][41][42]44,46,50 This wide range can be due to patient, treatment, and follow-up heterogeneity across studies. Table 2 summarizes results of selected series.…”

“…39 We reported our experience with 21 patients treated with SBRT for liver metastases with median dose 40 Gy (20-50 Gy) in one to 10 fractions. 42 Treatment was well tolerated and toxicity was mild with the exception of one case of transient colitis. Actuarial overall one-and two-year survival rates were 94 and 60% and actuarial one-and two-year local control rates were 62 %.…”

To degas or not to degas? The effectiveness of pharmaceuticals in reducing the impact of bowel volume variations during liver SBRT treatment

“…1 This is due to the liver's low tolerance to radiation and the previous inability to use steep dose gradients to spare healthy tissue. 1 The indications for liver SBRT continue to expand the management of liver cancer due to the improved rates of local control with acceptable normal tissue toxicity. 2 This is achieved through the creation of steep dose gradients that deliver ablative doses to the tumour volume whilst sparing normal tissues.…”

“…While motion management has facilitated the use of reduced margins, variations in anatomy can still occur that are unrelated to respiratory motion, such as bowel volume variations. 1,2 Liver SBRT is often used to treat secondary liver cancers and, in most cases, is considered a life lengthening rather than a curative treatment with the goal of achieving durable local control or a curative intent in oligometastatic settings. 3,4 Preservation of patient quality of life (QoL) is therefore an important consideration when designing treatment.…”

“…Conventional external beam radiation therapy (EBRT) has traditionally played a limited role in the management of liver cancer 1 . This is due to the liver's low tolerance to radiation and the previous inability to use steep dose gradients to spare healthy tissue 1 .…”