Adult ; Aged ; Bone Neoplasms/diagnostic imaging* ; Bone Neoplasms/radiotherapy* ; Bone Neoplasms/secondary* ; Carcinoma, Hepatocellular/radiotherapy* ; Female ; Fluorodeoxyglucose F18/metabolism ; Humans ; Kaplan-Meier Estimate ; Liver Neoplasms/radiotherapy* ; Male ; Middle Aged ; Palliative Care/methods* ; Positron-Emission Tomography/methods ; Radiopharmaceuticals*/metabolism ; Republic of Korea ; Treatment Outcome
Keywords
FDG-PET ; SUV ratio ; bone metastasis ; hepatocellular carcinoma ; radiotherapy
Abstract
AIMS: To determine the utility of FDG-PET in predicting long-term infield tumour control after RT in patients with metastatic hepatocellular carcinoma (HCC) to bone.
METHODS:Among 223 patients with HCC skeletal metastases diagnosed, we reviewed 22 patients with 45 total sites treated with RT who had at least two FDG-PETs prior to and after RT. The median RT dose was 42 Gy (range, 22-48) with a median fraction of 3 Gy (range, 2-8). Helical tomotherapy was generally offered for lesions that received higher RT dose (36%). The intrahepatic control rate in all patients was 73% at the time of referral. The ratio of tumour SUV to blood-pool activity SUV (SUV-ratio) was calculated. The primary end-points were infield progression-free survival (infield-PFS) and infield event-free survival (infield-EFS; recurrent and intractable pain or skeletal-related events).
RESULTS:Among 45 sites, 20 had tumour progression and 21 developed events in the previously treated area. A higher SUV-ratio before RT, SUV-ratio decline and higher radiation dose were independently and significantly correlated with better infield-PFS (both P<0.05). The tumours with a pre-RT SUV-ratio≥3.0 and SUV-ratio decline≥40% had significantly better infield-PFS and EFS than those with either a pre-RT SUV-ratio<3.0 or SUV-ratio decline<40% (both P<0.05).
CONCLUSIONS:FDG-PET may help to predict outcomes of infield tumour control following palliative RT for treatment of HCC bone metastases. Tumours with low metabolic uptake before RT or with a minor decline in post-RT SUV-ratio showed poor long-term infield tumour control.