Radiation lobectomy: Time-dependent analysis of future liver remnant volume in unresectable liver cancer as a bridge to resection

Abstract

Background & Aims Portal vein embolization (PVE) is a standard technique for patients not amenable to liver resection due to small future liver remnant ratio (FLR). Radiation lobectomy (RL) with 90Y-loaded microspheres (Y90) is hypothesized to induce comparable volumetric changes in liver lobes, while potentially controlling the liver tumor and limiting tumor progression in the untreated lobe. We aimed at testing this concept by performing a comprehensive time-dependent analysis of liver volumes following radioembolization. Methods 83 patients with right unilobar disease with hepatocellular carcinoma (HCC; N = 67), cholangiocarcinoma (CC; N = 8) or colorectal cancer (CRC; N = 8) were treated by Y90 RL. The total liver volume, lobar (parenchymal) and tumor volumes, FLR and percentage of FLR hypertrophy from baseline (%FLR hypertrophy) were assessed on pre- and post-Y90 CT/MRI scans in a dynamic fashion. Results Right lobe atrophy (p = 0.003), left lobe hypertrophy (p <0.001), and FLR hypertrophy (p <0.001) were observed 1 month after Y90 and this was consistent at all follow-up time points. Median %FLR hypertrophy reached 45% (5–186) after 9 months (p <0.001). The median maximal %FLR hypertrophy was 26% (−14→86). Portal vein thrombosis was correlated to %FLR hypertrophy (p = 0.02). Median Child-Pugh score worsening (6→7) was seen at 1 to 3 months (p = 0.03) and 3 to 6 months (p = 0.05) after treatment. Five patients underwent successful right lobectomy (HCC N = 3, CRC N = 1, CC N = 1) and 6 HCCs were transplanted. Conclusions Radiation lobectomy by Y90 is a safe and effective technique to hypertrophy the FLR. Volumetric changes are comparable (albeit slightly slower) to PVE while the right lobe tumor is treated synchronously. This novel technique is of particular interest in the bridge-to-resection setting.

Contra-lateral liver lobe hypertrophy after unilobar Y90 radioembolization: An alternative to portal vein embolization?

“…Subsequently, several groups have also published similar results from their retrospective experience [15][16][17][18][19][20][21][22] . The main limitations of these retrospective studies are that the patient cohorts were vastly heterogenous in terms of pathology treated, underlying liver disease, dosage and delivery of Y90, number of treatment sessions and time to measurement of hypertrophy.…”

“…Although subject to the usual biases inherent in such a study, the authors demonstrated that PVE produced significantly more hypertrophy (61.5% vs 29.0%) within a shorter time frame (median 33 d vs 46 d). Another recent study [18] attempted to study the relationship between the degree of hypertrophy with duration from treatment. In this study, median FLR growth progressed from 7% at one month to 45% at 9 mo post-radioembolization.…”

A systematic review of contralateral liver lobe hypertrophy after unilobar selective internal radiation therapy with Y90

“…Thus while the degree of growth achieved is comparable to that achieved with PVE alone, and superior to that achieved after PVE + TACE, the kinetics of hypertrophy after SIRT are likely to be different from PVE. This is further borne out in the study by Vouche et al, 15 which showed only limited hypertrophy in the early post-treatment period. The recent development of another novel technique for inducing liver hypertrophy, i.e.…”

“…20 Nine studies, published between 2008 and 2014 were identified. [11][12][13][14][15][16][17][18][19] Three studies 11,12,15 were reported from the same centre with overlapping patient cohorts. Two studies 11,12 were excluded; and only the most recent (and largest) report 15 was included.…”

Neoadjuvant transarterial radiation lobectomy for colorectal hepatic metastases: a small cohort analysis on safety, efficacy, and radiopathologic correlation

“…In distinction to conventional radioembolization, RL delivers intentionally ablative transarterial brachytherapy to both tumor and adjacent hepatic substrate. It is well-tolerated, generates FLR hypertrophy equivalent or greater to PVE, and can be used in patients with PVT or concurrent systemic chemotherapy (23,24). Contrary to PVE or ALPPS, RL has potential to control disease which permits FLR hypertrophy over several months allowing for surveillance of tumor biology.…”