PET/CT and hepatic radiation injury in esophageal cancer patients

Abstract

This paper evaluates the imaging appearance of radiation injury in the liver on positron emission tomography (PET)/computed tomography (CT) in patients with distal esophageal cancer who underwent pre-operative chemoradiation therapy. Twenty-six patients with distal esophageal cancer who received chemoradiotherapy before esophagectomy were included. All patients had baseline and follow-up PET/CT. Fluorodeoxyglucose (FDG) uptake in both left and right lobes of the liver was evaluated. CT findings suggesting radiation damage were documented. Abnormal FDG uptake in the liver was observed in 5 (19%) patients after therapy. These abnormalities were in the left lobe (12%) and right lobe (12%) of the liver. In the irradiated left lobe, FDG uptake increased focally greater than 50% over baseline in two patients (54% and 133%); in one of these patients, biopsy confirmed radiation injury. In the non-irradiated right lobe, standard uptake values (SUV) increased diffusely in two different patients. In one patient, SUV decreased by at least 50% in both the right and left lobes. In the remaining patients, there were no significant changes in FDG uptake. Atrophy and attenuation changes of irradiated liver on CT were found in 15 (58%) patients. In patients receiving chemoradiotherapy, PET/CT may identify metabolic abnormalities in irradiated liver. Such abnormalities should be correlated with other imaging, clinical and laboratory findings to avoid confusion with hepatic metastases.

Radiation-induced liver disease as a mimic of liver metastases at serial PET/CT during neoadjuvant chemoradiation of distal esophageal cancer

“…In parallel with this therapeutic advance, PET/CT has become increasingly used as valuable imaging tools, both for baseline staging and for evaluation of treatment response [7–14]. However, it is known that radiation-induced liver disease can be a complication of radiotherapy, and one small study (n = 26) suggested that it may cause potentially confusing increased FDG avidity in the liver [13]. Therefore, we undertook this study to determine the frequency and appearance of radiation-induced liver disease on PET/CT in patients undergoing serial imaging during neoadjuvant chemoradiation of distal esophageal cancer.…”

Radiation-Induced Liver Injury Mimicking Metastatic Disease in a Patient With Esophageal Cancer

“…9 Preoperative whole-body PET/CT is frequently used to evaluate radiation treatment response and exclude metastases. Radiation-induced liver injury may be detected by PET/CT within 2 to 6 weeks after completion of radiation therapy, as a focal area of increased FDG uptake (>50% over baseline) in the liver adjacent to the irradiated field with associated decreased attenuation on CT. 10 As in our case, accompanying abnormalities in Alk Phos may be present in otherwise asymptomatic patients. 10 The FDG avidity is thought to represent uptake in active leukocytes because of inflammatory response in the liver.…”

“…Radiation-induced liver injury may be detected by PET/CT within 2 to 6 weeks after completion of radiation therapy, as a focal area of increased FDG uptake (>50% over baseline) in the liver adjacent to the irradiated field with associated decreased attenuation on CT. 10 As in our case, accompanying abnormalities in Alk Phos may be present in otherwise asymptomatic patients. 10 The FDG avidity is thought to represent uptake in active leukocytes because of inflammatory response in the liver. 11 A recent study found that 9% of patients developed new FDG uptake in the liver during neoadjuvant chemoradiation for distal esophageal carcinoma, of which 8% proved to be radiation-induced liver injury rather than metastases.…”

Quantitative/Objective Analyses of RT-Induced Late Normal Tissue Injury Using Functional Imaging

“…Abnormal FDG uptake in the irradiated liver was found in 19 % of the patients (Fig. 23) (Iyer et al 2007). However, CT images demonstrated atrophy and density changes of irradiated liver in 58 % of the same patients group.…”