Dose-related fluorodeoxyglucose uptake in acute radiation-induced hepatitis

Abstract

Therapeutic assessment with fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) is sometimes problematic after radiation therapy. Herein we describe a patient with acute radiation-induced hepatitis in which PET showed dose-dependent FDG uptake. A 50-year-old man underwent FDG PET for staging of esophageal cancer. Chemoradiotherapy was delivered concurrently with a radiation field that expanded from the esophagus into the upper stomach to cover metastasis of the gastric wall. The patient also underwent FDG PET 26 days and 4 months after chemoradiotherapy to evaluate the therapeutic effect. Twenty-eight days after chemoradiotherapy, hematochemistry revealed elevated hepatic enzymes and postcontrast computed tomography showed band-like hypoattenuation in the liver with parenchymal swelling corresponding to the radiation field. FDG PET performed 26 days after chemoradiotherapy showed a wedge-shaped hypermetabolic area in which the degree of FDG uptake correlated with the prescribed radiation dose. Follow-up PET 4 months after therapy showed no abnormal uptake in the liver. Acute radiation-induced hepatitis can be a potential cause of false-positive findings of malignancy on FDG PET scans, and PET images should carefully be compared with the distribution of prescribed dose. Threshold dose might be higher for metabolic changes than for morphologic changes.

Focal Hepatic Fluorodeoxyglucose Uptake Mimics Liver Metastasis Following External Beam Radiation for Gastroesophageal Cancers: A Case and Review of the Literature

“…[57] Nakahara et al reported a case of FDG uptake in the left lobe of liver 28 days after completion of radiation for esophageal cancer, with resolution on follow-up PET scan 3 months later, consistent with our cases. [8] In our series, we found FDG uptake within 34 and 42 days postradiation. Interestingly, among the remaining 62 patients in our database, hepatic FDG-uptake was not observed, suggesting that intrinsic biologic features in addition to treatment and imaging timing may play a role.…”

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

“…In one study it was shown that up to 35% of patients with esophageal cancer will develop liver metastases [29]. In addition to metastatic disease, the liver is also particularly prone to radiation-induced liver disease during radiotherapy of distal esophageal cancer, due to the close proximity of the left lobe which is accordingly included in the standard radiation field [27–29].…”

“…In one study it was shown that up to 35% of patients with esophageal cancer will develop liver metastases [29]. In addition to metastatic disease, the liver is also particularly prone to radiation-induced liver disease during radiotherapy of distal esophageal cancer, due to the close proximity of the left lobe which is accordingly included in the standard radiation field [27–29]. Given that serial PET/CT is increasingly performed during neoadjuvant chemoradiation of esophageal cancer and that both metastases and radiation-induced liver disease may manifest as increased foci of FDG avidity at PET scanning, our study provides important results that address how these two entities might be distinguished.…”

Phantom simulation of liver metastasis on a positron emission tomography with computed tomography scan after neoadjuvant chemoradiotherapy for distal esophageal cancer: a case report

“…Common sites of metastatic spread in esophageal cancer include the abdominal lymph nodes, liver, and lungs [10]. In one study, it was revealed that up to 35% of patients with esophageal cancer will develop liver metastases [11]. In addition to metastatic disease, the liver is also particularly prone to radiation-induced liver disease (RILD) during RT for distal esophageal cancer, owing to its close proximity to the left lobe, which is accordingly included in the standard radiation field [11].…”

“…In one study, it was revealed that up to 35% of patients with esophageal cancer will develop liver metastases [11]. In addition to metastatic disease, the liver is also particularly prone to radiation-induced liver disease (RILD) during RT for distal esophageal cancer, owing to its close proximity to the left lobe, which is accordingly included in the standard radiation field [11]. When a patient displays FDG activity in the left or caudate liver lobes after CRT, a more detailed investigation should be performed in order to confirm or exclude distant metastases [12].…”