Determination and comparison of radiotherapy dose responses for hepatocellular carcinoma and metastatic colorectal liver tumours

Abstract

Objective: The purpose of this study was to seek radiation dose responses separately for primary hepatocellular carcinoma (HCC) and metastatic (MET) colorectal liver tumours to establish tumour control probabilities (TCPs) for radiotherapy (RT) of liver tumours. Methods: The records of 36 HCC and 26 MET colorectal liver tumour patients were reviewed. The median dose per fraction and total dose were 4 Gy (2-10 Gy) and 52 Gy (29-83 Gy) for the HCC group and 3.6 Gy (2.0-13.0 Gy) and 55 Gy (30-80 Gy) for the MET group, respectively. Median tumour diameter was 6.6 cm (3.0-18.0 cm) and 5.0 cm (1.0-13.0 cm) for the HCC and MET groups, respectively. A logistic TCP model was fitted to the response data for each group using the maximum likelihood method.Results: 50% and 90% probabilities of 6-month local control were estimated to be achievable by 2 Gy per fraction equivalent doses (a/b510 Gy) of 53 Gy and 84 Gy for the HCC group and 70 Gy and 95 Gy for the MET group, respectively. Actuarial 1-year local control for the HCC and MET groups was 65% (45-85%) and 32% (6-58%), respectively, whereas median time to failure was 543 days (374-711 days) and 183 days (72-294 days), respectively. Conclusion: Dose-response relationships were found and modelled for the HCC and MET patient groups, with a higher dose required to control MET tumours. RT offers better local control for HCC than for MET colorectal liver tumours at our institution. Advances in knowledge: An improved understanding of radiation dose-response relationships for primary and MET colorectal liver tumours will help inform future dose prescriptions.

Insights into the Dose–Response Relationship of Radioembolization with Resin 90Y-Microspheres: A Prospective Cohort Study in Patients with Colorectal Cancer Liver Metastases

“…The dose-response associations derived from these studies are, however, not directly comparable to our findings. For one, radiosensitivity may be dependent on tumor type, similar to findings in external-beam radiotherapy (21). Furthermore, tumorabsorbed dose values are generally higher with glass microspheres, but this does not necessarily imply greater treatment efficacy.…”

Whole-liver Radiotherapy Concurrent with Chemotherapy as a Palliative Treatment for Colorectal Patients with Massive and Multiple Liver Metastases: a Retrospective Study

“…Areas less than one-third to one-half of the liver volume can tolerate more than 55 Gy. A study reported that liver lesions could be boosted to a total of 83 Gy (Lausch et al, 2013). We found that conventional fraction intense-modulated radiotherapy reduced liver damage and encouraged more normal cell regeneration than hyperfractioned radiotherapy, according to radiation biology (Dimri et al, 2013).…”

Assessing the Clinical Impact of Approximations in Analytical Dose Calculations for Proton Therapy

“…The required parameters D 50 and γ 50 , representing the dose needed for 50% tumor control and the slope of the response curve at that point, were obtained from the literature. The following [D 50 , γ 50 ] values were applied: breast [56.77, 1.48] (19), head-and-neck [59.3, 2.0] (20), liver [53.0, 1.2] (21), lung [74.5, 3.52] (22), and prostate [75.5, 2.25] (23). All treatment regimens employed have been translated to 2Gy/fraction schedules using the linear-quadratic model with α/β=10Gy for all sites except prostate, where a value of 2Gy was used (24).…”