Importance of screening for synchronous malignant neoplasms in patients with hepatocellular carcinoma: impact of FDG PET/CT

Synchronous Colorectal and Prostate Cancer: Dual PET/CT Approach for Detecting and Distinguishing Metastatic Patterns

Prostate cancer (PC) and colorectal cancer (CRC) are two of the leading causes of cancer-related mortality. The incidence of synchronous neoplasms in patients with CRC is increasing, though synchronous PC and CRC remains a rare occurrence in clinical practice. Early diagnosis, accurate staging, and characterization of tumors are essential for selecting patient-tailored therapy. The origin of metastatic disease in synchronous cases presents a challenge for conventional imaging modalities, but advances in molecular imaging have addressed this limitation. Positron emission tomography/computed tomography (PET/CT) is now the preferred modality for assessing synchronous cases. The authors present a 72-year-old male patient with the rare occurrence of two coexisting primary cancers. At first, fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT detected the first colorectal primary tumor extension along with evidence of heterogeneous 18F-FDG activity within an enlarged prostate, warranting further evaluation. Subsequently, gallium-68 prostate-specific membrane antigen (68 Ga-PSMA) PET/CT imaging revealed the second prostate primary cancer with evidence of bone metastases. Adoption of a dual PET/CT approach in cases where biopsy is impractical can achieve accurate staging results during the initial diagnostic workup.

FDG PET/CT to Detect Incidental Findings in Patients With Hepatocellular Carcinoma-Additional Benefit for Patients Considered for Liver Transplantation?

PURPOSE

FDG PET/CT has been described for noninvasive grading, detection of extrahepatic spread, and recurrence in hepatocellular carcinoma (HCC). As compared with localized imaging approaches (MRI, ultrasonography), FDG PET/CT not only focuses on the liver, but covers a long field of view from the base of the skull to the thighs, visualizing pathologic findings not related to HCC. The aims of this retrospective study were to (1) describe the frequency of relevant incidental findings on FDG PET/CT in HCC patients, (2) evaluate the impact on treatment strategy in HCC patients considered for liver transplantation, and (3) to discuss the role of FDG PET/CT in patients considered for transplantation in general.

METHODS

Four hundred thirty-nine FDG PET/CT examinations of 345 HCC patients were screened for incidental findings. The clinical information system was searched for examinations performed after FDG PET/CT and aimed at verification of incidental findings. Of 345 HCC patients, 81 patients were considered for liver transplantation. The impact of incidental findings was recorded separately for this subgroup.

RESULTS

One hundred one patients with incidental findings in 439 FDG PET/CT examinations were identified. The incidental findings comprised 22 neoplasms (9 malignant) and 52 inflammations. Liver transplantation was not performed because of an incidental finding on FDG PET/CT in 9 (11.1%) of 81 patients.

CONCLUSIONS

FDG PET/CT is capable of identifying relevant incidental findings (ie, secondary malignancy, benign tumors, and inflammation) in HCC patients and HCC patients considered for liver transplantation and thus influencing HCC patient management. FDG PET/CT might also be beneficial in patients considered for transplantation of different organs.

Clinical relevance of incidental focal breast uptake on fluorine-18 fluorodeoxyglucose PET/computed tomography studies: an experience in a high-load center of Spain

AIM

We aimed to determine the frequency and clinical significance of breast incidental uptake (BIU) detected through fluorine-18 fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) in a single, high-load center.

PATIENTS AND METHODS

In this retrospective study, we analyzed a total of 13 763 PET/CT studies performed from January 2017 to January 2020. After excluding 3148 scans, the maximum standardized uptake value (SUVmax) and maximum diameter (cm) of each BIU were measured. Clinical management, ultrasound/mammography and pathology reports were analyzed.

RESULTS

We found BIU in 27 scans of 26 patients (0.3% of the studies). Mean age was 62.2 years and 88.5% were women; 84.6% underwent PET/CT for oncological indications. Ultrasound/mammography was consequently performed in 23 patients (88.5%), and histological correlations were available for Breast Imaging Reporting and Data System categories 4 and 5. Finally, lesions were benign in 14 patients (60.9%; two of them with low/intermediate risk of malignancy) and malignant in nine patients (39.1%). The remaining three patients had no ultrasound/mammography reports. Mean SUVmax of benign and malignant lesions were 2.6 ± 1.4 and 5.8 ± 3.5, respectively (P = 0.002). Considering a SUVmax cut-off value of 4.0, the sensitivity and specificity for differentiating benign vs. malignant lesions were 67 and 93%, respectively. Benign lesions were smaller than malignant in CT (maximum diameter:1.3 ± 0.5 cm vs. 2.0 ± 1.0 cm, P = 0.02).

CONCLUSION

Although BIU detected by 18F-FDG PET/CT is infrequently found, the risk of malignancy remains very high (39.1%). Both SUVmax and maximum diameter were greater in malignant than in benign lesions. An exhaustive study with ultrasound/mammography and selective histopathological correlation is mandatory after BIU findings, even in small lesions.

Positron-emission tomography for hepatocellular carcinoma: Current status and future prospects

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality worldwide. Various imaging modalities provide important information about HCC for its clinical management. Since positron-emission tomography (PET) or PET-computed tomography was introduced to the oncologic setting, it has played crucial roles in detecting, distinguishing, accurately staging, and evaluating local, residual, and recurrent HCC. PET imaging visualizes tissue metabolic information that is closely associated with treatment. Dynamic PET imaging and dual-tracer have emerged as complementary techniques that aid in various aspects of HCC diagnosis. The advent of new radiotracers and the development of immuno-PET and PET-magnetic resonance imaging have improved the ability to detect lesions and have made great progress in treatment surveillance. The current PET diagnostic capabilities for HCC and the supplementary techniques are reviewed herein.

Detection of additional primary malignancies: the role of CT and PET/CT combined with multiple percutaneous biopsy

Objective

To evaluate the imaging findings of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and computed tomography (CT) in patients with additional primary tumors, correlating the results with those of the method used in order to elucidate the diagnosis and of the pathology reports.

Materials and Methods

We retrospectively analyzed the medical records, pathology reports and images of 11 patients who underwent CT, ¹⁸F-FDG PET/CT, or both. We included patients with at least two tumors, with confirmed distinct histopathological profiles, at different sites. Patients in whom there was no diagnostic confirmation were excluded, as were those in whom the additional lesion was suspected of being a metastasis of the first.

Results

New primary malignancies were identified in 11 patients, one new tumor being found in 10 and two new tumors being found in 1. The confirmed sites of the additional malignancies were the lung, kidney, prostate, jejunum, and breast. Single or multiple percutaneous biopsies were performed in 10 patients, and 1 patient underwent a surgical procedure for diagnostic and therapeutic purposes. The tumors were metachronous in 6 cases and synchronous in 5.

Conclusion

CT and ¹⁸F-FDG PET-CT combined with multiple percutaneous biopsy could facilitate the diagnosis of additional lesions, thus optimizing the treatment and follow-up of the affected patients.

Triple primary cancer of the head and neck, skin and prostate: A case report and literature review

Second primary cancer (SPC) is an important prognostic factor for patients with head and neck cancer (HNC); therefore, the association between the prognosis and development of SPC has been well-reported. The use of 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) is valuable to examine cancer stage, evaluate treatment responses and investigate suspected relapses or metastases. In the present study, the case of a male patient who was diagnosed with three primary cancer types, including well to moderately differentiated squamous cell carcinoma (SCC) of the mandible, axillary cutaneous poorly differentiated SCC and prostate adenocarcinoma, was described. Among these, mandible cancer was the first diagnosed when the patient was 70 years of age. Synchronous skin and prostate cancer (PRC) types then developed 3 years later. To the best of our knowledge, this is the first report of the aforementioned combination of cancer types. Postoperative FDG-PET was not performed as no lesions of recurrence or metastases of mandible cancer were found. Three years later, the PRC was asymptomatic and was incidentally detected by FDG-PET performed for a preoperative evaluation of skin cancer. It was indicated that FDG-PET could be utilized in patients with HNC due to there being no accurate FDG-PET protocol to detect SPC over a long-term follow-up.

Radiological biomarkers for assessing response to locoregional therapies in hepatocellular carcinoma: From morphological to functional imaging (Review)

Many hepatocellular carcinoma (HCC) patients do not qualify for curative surgical intervention and are instead treated with locoregional therapies (LRTs) including ablative and endovascular therapies. Assessment of imaging response is essential in the management of HCC for determining efficacy of therapy and as a surrogate marker for improved survival. The established morphological image biomarkers for tumor burden measurement continue to be applied, as size measurement can easily be used in clinical practice. However, in the setting of liver-directed LRTs for HCC, simple tumor morphological changes can be less informative and usually appear later than biologic changes. Functional imaging (such as perfusion and diffusion imaging, PET-CT/MR and MR spectroscopy) has the potential to be a promising technique for assessment of HCC response to LRTs. Although promising, none of these functional imaging biomarkers have gone through all the required steps of standardization and validation and established accepted criteria for clinical practice.

18F-FDG PET in Liver Transplantation Setting of Hepatocellular Carcinoma: Predicting Histology?

PURPOSE

The aim of this study was to evaluate the prognostic value of F-FDG PET/CT by predicting histopathological findings in the pretransplant evaluation of patients with hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

F-FDG PET/CT findings of 34 patients with HCC who underwent liver transplantation were reviewed retrospectively. Visual and quantitative analysis (tumor standardized uptake values normalized to the background activity of the liver: SUVmax T/L) was done. PET tumor characteristics were compared with the histological analysis (differentiation and microvascular invasion). All patients were followed up (mean, 12 months).

RESULTS

Ten patients showed tumoral uptake greater than background activity (PET+). Higher-grade tumor was more common in the F-FDG-avid tumor group (P < 0.05). PET+ also showed more microvascular invasion at explant pathology (P < 0.05). Only 1 patient PET+ developed HCC early recurrence (4 months) with an SUVmax T/L of 1.64.

CONCLUSIONS

F-FDG uptake is predictive for microvascular invasion and tumor differentiation. This examination has a prognostic value regarding tumor recurrence after liver transplantation for HCC.

Role of positron emission tomography/computed tomography in living donor liver transplantation for hepatocellular carcinoma

Living donor liver transplantation (LDLT) becomes an important option for treatment for patients with hepatocellular carcinoma (HCC). With the advance of imaging modalities such as computed tomography (CT) and magnetic resonance image (MRI), preoperative staging and diagnosis for HCC was improved in LDLT. However, morphological characteristics based on the tumor number and size do not represent the tumor pathology and prognosis clearly. Therefore, many criteria using various markers have been reported, but still have limitation to predict the pathology and prognosis. Recently, 18F-fluorodeoxyglucose-positron emission tomography/CT (18F-FDG PET/CT) was introduced to have the usefulness for detection of extrahepatic metastases and prediction of post-transplant prognosis in liver transplantation (LT). Furthermore, the hybrid concept with both biologic activity using PET/CT and morphologic tumor characteristics using CT and MRI was reported to be selection criteria for the patient with HCC waiting LDLT. We will discuss the role of 18F-FDG PET/CT in LDLT as various aspects including tumor detection, pathology prediction, prognosis prediction, and possibility of selecting criteria.

Hepatocellular Carcinoma associated with Extra-hepatic Primary Malignancy: its Secular change, Clinical Manifestations and Survival

Clinical manifestations between hepatocellular carcinoma (HCC) and extra-hepatic primary malignancy (EHPM) are lack of large-scale study. We enrolled 14555 HCC patients between 1986 and 2013 retrospectively. The EHPM was classified as prior, synchronous and metachronous group based on before, within and after 6 months of HCC diagnosis, respectively. The incidence rate of EHPM is 3.91% (95% confidence interval [CI]: 3.60–4.23%). Urogenital cancers, kidney and bladder, were at unexpected higher ranks. Older in age, Child-Pugh A cirrhosis, negativity of HBsAg and anti-HCV, and earlier BCLC staging are independent factors associated with EHPM. The survival rates of EHPM improve over time and also better than HCC-alone. Cox proportional-hazards regression shows independent poor prognostic factors are age >60, male, AFP levels ≥400 ng/ml, positivity of HBsAg, Child-Pugh B vs. A, Non-metachronous group, respectively, treated with local ablation, transcatheter arterial embolization, radiotherapy and supportive care vs. surgery, respectively, TNM stage IIIA vs. I, and BCLC stages A, B, C and D vs. 0, respectively. Survival of EHPM improve could be explained by early diagnosis and improve treatment of cancers.

Positioning of 18F-fluorodeoxyglucose-positron emission tomography imaging in the management algorithm of hepatocellular carcinoma

BACKGROUND AND AIM

(18) F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) may detect primary lesions (PLs) and extrahepatic metastases (EHMs) only in advanced hepatocellular carcinoma (HCC) patients. We investigated the requirement of PET and the optimal timing of PET scanning for accurate staging and treatment planning.

METHODS

We conducted a retrospective investigation of 64 HCC patients who underwent PET (median age, 74 years; male/female, 41/23; etiology, 46 hepatitis C virus/4 hepatitis B virus/4 alcoholic/10 others). To determine the best timing for PET examinations, we analyzed PET result-based recommended treatment changes and characteristics of patients with FDG-avid PLs or EHMs.

RESULTS

FDG-avid PLs were detected by PET in 22 patients (34%): 18 with hypervascular PL, 11 with serum α-fetoprotein levels ≥ 200 ng/mL, and 11 beyond Milan criteria. EHMs were detected in 21 patients (33%: lymph nodes, 8; lung, 5; abdominal wall, 4; bone, 3; other organs, 4 [including overlapping]). Recommended treatments changed for 16 patients (25%) because of Barcelona Clinic Liver Cancer stage increases based on PET scanning. In multivariate analyses, serum α-fetoprotein levels ≥ 200 ng/mL and beyond Milan criteria were independent factors for FDG-avid PLs and a maximum standardized uptake value (SUVmax) of PLs of ≥ 4.0 was an independent factor for FDG-avid EHMs (P = 0.002, 0.008, and 0.045, respectively).

CONCLUSIONS

PET allows detection of HCC spread in patients with elevated serum α-fetoprotein levels or those beyond Milan criteria and detects EHMs in patients with PLs with high SUVmax values. Optimally timed PET scans can complement conventional imaging for accurate staging and treatment strategy determination.