Liver Function Investigation With SPECT

This is a Phase 1 pilot study to assess feasibility and utility of 99mTc-mebrofenin hepatobiliary scintigraphy for measurement of functional liver change due to radiotherapy.

Patients with cancers of the liver who are not suitable for surgery or chemo/radio embolisation are often treated with stereotactic ablative body radiotherapy (SABR). SABR results in high local control rates but, similar to other treatment modalities, carries risk of damage to healthy surrounding liver. This study aims to use a novel nuclear medicine imaging tracer, 99mTcMebrofenin, to evaluate liver function before and after radiotherapy. Patients will have a 99mTcMebrofenin scan performed \< 2 weeks before radiotherapy and 1 and 6 months after radiotherapy. At the same time points, indocyanine green (ICG) and liver elasticity tests will be performed. These are global measures of liver function, whereas 99mTcMebrofenin is both global and local. From the imaging data, the Investigators will be able to correlate change in local liver function in each sub volume of the liver with the radiotherapy dose it received. The Investigators will be able to thus measure the effect of radiotherapy on global and local liver function.

Inclusion Criteria: * Aged 18 or older * Has provided written Informed Consent for participation in this trial and is willing to comply with the study * Patients undergoing external beam radiotherapy at Northern Sydney Cancer Centre * Histologically proven hepatocellular carcinoma or oligometastatic liver metastases (3 or less). Histological diagnosis will be obtained if clinically indicated. * ECOG performance status 0-2 Exclusion Criteria: * Previous high-dose radiotherapy to the liver * Previous SIRT * Women who are pregnant or lactating * Unwilling or unable to give informed consent * No venous access * Inability to lie supine and still for 30 minutes * History of allergic reactions attributed to compounds of similar chemical or biologic composition to indocyanine green, including those patients with a history of iodide or seafood allergy (excluded from ICG testing only) * Pacemaker (excluded from Fibroscan elasticity test only)