The role of FDG-PET in defining prognosis of Hodgkin lymphoma for early-stage disease

Abstract

Given the excellent survival rates for early-stage Hodgkin lymphoma (HL), the young age of many patients, and concerns regarding acute and late treatment-related toxicities, there is a desire to have a predictive tool that enables therapy to be tailored toward the individual patient. Early (or interim) 18F-fluorodeoxyglucose positron emission tomography with computerized tomography (FDG-PET/CT), as a test of tumor sensitivity to ongoing/planned therapy, has been shown to be prognostic for survival in HL. Based on results of interim FDG-PET/CT, therapy may be subsequently modified through minimization or via intensification for low- and high-risk patient populations, respectively (ie, response-adapted therapy). Important data have been generated to standardize the interpretability and reproducibility of interim FDG-PET/CT (eg, the Deauville 5-point system), and observational and noncontrolled prospective studies have produced evidence supporting the hypothesis that response-adapted therapy may potentially serve as a predictive tool. Furthermore, results from noninferiority phase 3 clinical trials randomizing early-stage HL patients with negative interim FDG-PET/CT to combined modality therapy versus chemotherapy alone have been reported. The current collective findings from these randomized early-stage HL studies have shown that acute relapse rates are lower with combined modality therapy, even in patients with negative interim FDG-PET/CT. Additional randomized response-adapted studies are ongoing and novel FDG-PET/CT applications involving quantitative techniques and innovative imaging modalities are being investigated to identify more robust imaging biomarkers. Treatment of early-stage HL remains a clinical management choice for physicians and patients to make with consideration of acute and long-term outcomes.

Interim FDG-PET/CT in Hodgkin lymphoma: the prognostic role of the ratio between target lesion and liver SUVmax (rPET)

“…An important research goal is early identification of patients with poor prognosis, who could take advantage of an intensified therapy scheme. Interim 18F-Fluoro-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging after the first two cycles of ABVD has proved to be a powerful prognostic tool in patients with HL [1][2][3]. A 5-point scoring system using the Deauville criteria (5p-Deauville Score, 5p-DS) has been proposed as a qualitative visual method to evaluate interim FDG-PET/CT and been widely accepted to be the best predictor of outcome [4].…”

PET response-adapted clinical trials in Hodgkin lymphoma: a comprehensive review

“…In stage I-IIA a joint American-Canadian study showed that freedom from disease progression was superior in patients achieving a complete or unconfirmed complete remission after two cycles of ABVD (P = 0.007; 5-year survival estimates, 95 vs 81 %) than those who did not after completing therapy with two more cycles with no ensuing RT [42]. Compared to traditional radiological imaging by CT, FDG-PET/CT may provide further prognostic information combining morphological (tumour shrinkage) and functional (in vivo evaluation of chemo-sensitivity) parameters to assess early treatment response [43]. However, there are comparatively much less data on the predictive role on long term treatment outcome of interim PET in early as compared to advancedstage HL, and results are controversial.…”

Computed Tomography Observer Agreement in Staging Malignant Lymphoma

“…11 Corresponding Ann Arbor stages were assigned, and in case of no residual tumor on 18 F-FDG-PET/ CT after diagnostic biopsy, Ann Arbor stage was defined as stage I. In this subgroup, CT Ann Arbor stage was compared with 18 F-FDG-PET/CT Ann Arbor stage (gold standard).…”

“…In the subgroup of 23 patients who underwent CT scanning with use of a PET/CT system (Siemens Healthcare Biograph 40 True Point PET/CT [n = 20] and Philips Healthcare Gemini TOF PET/CT [n = 3]), 18 F-FDG-PET/CT scanning was also performed. Patients fasted for at least 6 hours, and blood glucose levels were checked to be less than 11 mmol/L before 3 MBq/kg FDG was administered intravenously.…”

“…Poor agreement could be due to the difficulty in defining the exact location of an involved region, discrepancies in lymph node short-axis size measurements, or other reader errors (eg, lymph nodes with a short axis exceeding 10 mm that had been classified as negative). 18 F-FDG-PET/CT scans of the subset of 23 patients were evaluated by a nuclear medicine physician (with >5 years of PET/ CT experience), who assessed the same previously defined nodal and extranodal regions. The observer was blinded to the findings of the CT observers, other imaging findings (including whole-body magnetic resonance imaging), and other clinical findings (including bone marrow biopsy).…”