Prognostic value of bone marrow tracer uptake pattern in baseline PET scans in hodgkin lymphoma: Results from an international collaborative study

PET/CT-ascertained bone marrow involvement (BMI) constitutes the single most important reason for upstaging by PET/CT in Hodgkin lymphoma (HL). However, BMI assessment in PET/CT can be challenging. This study analyzed the clinicopathologic correlations and prognostic meaning of Different patterns of bone marrow (BM)18F-FDG uptake in HL. Methods: One hundred eighty newly Diagnosed early unfavorable and advanced-stage HL patients, all scanned at baseline and after 2 adriamycin-bleomycinvinblastine-dacarbazine (ABVD) courses with18F-FDG PET, enrolled in 2 international stuDies aimed at assessing the role of interim PET scanning in HL, were retrospectively included. Patients were treated with ABVD 4-6 cycles and involved-field raDiation when needed, and no treatment adaptation on interim PET scanning was allowed. Two masked reviewers independently reported the scans. Results: Thirty-eight patients (21.1%) had focal lesions (fPET1), 10 of them with a single (unifocal) and 28 with multiple (multifocal) BM lesions. Fifty-three patients (29.4%) had pure strong (.liver) Diffuse uptake (dPET1) and 89 (48.4%) showed no or faint (#liver) BM uptake (nPET1). BM biopsy was positive in 6 of 38 patients (15.7%) for fPET1, in 1 of 53 (1.9%) for dPET1, and in 5 of 89 (5.6%) for nPET1. dPET1 was correlated with younger age, higher frequency of bulky Disease, lower hemoglobin levels, higher leukocyte counts, and similar Diffuse uptake in the spleen. Patients with pure dPET1 had a 3-y progression-free survival identical to patients without any18F-FDG uptake (82.9% and 82.2%, respectively, P 5 0.918). However, patients with fPET1 (either unifocal or multifocal) had a 3-y progressionfree survival significantly inferior to patients with dPET1 and nPET1 (66.7% and 82.5%, respectively, P 5 0.03). The k values for interobserver agreement were 0.84 for focal uptake and 0.78 for Diffuse uptake. Conclusion: We confirmed that18F-FDG PET scanning is a reliable tool for BMI assessment in HL, and BM biopsy is no longer needed for routine staging. Moreover, the interobserver agreement for BMI in this study proved excellent and only focal18F-FDG BM uptake should be considered as a harbinger of HL

Positron Emission Tomography (PET) in Oncology

Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%–15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later

Dual-point FDG-PET/CT for treatment response assessment in Hodgkin lymphoma, when an FDG-avid lesion persists after treatment

FDG-PET/CT (PET) is now considered the standard imaging tool for Hodgkin Lymphoma (HL) staging and restaging. However a CT-detected residual mass at the end of therapy (EoT) is still a challenge for PET interpretation. The aim of our study was to improve the overall accuracy of EoT PET/CT by using a dynamic dual-point scanning at 60 and 120 after FDG injection (2P-PET/CT). Fifty-one HL patients showing a single residual FDG-avid mass (SFAM) at EoT PET/CT were included in the study in Italy and Poland. Treatment was ABVD, ABVD followed by BEACOPP or ABVD plus radiotherapy. Only patients with a SFAM and a Deauville score (DS) > 2 in EoT PET/CT were included in the study. Two independent nuclear medicine reviewed images with a semi-quantitative analysis (SUVMax and retention index, RI) and a visual scoring according to DS. Compared to standard PET, 2P-PET/CT showed only a modest increase in NPV and PPV, from 0.87 to 0.89 and of the PPV from 0.67 to 0.71, respectively. Increase of the overall accuracy became substantial upon including in the analysis only patients whose images were acquired in strict adhesion to original protocol of 2P-PET/CT scanning: (t 120'-6040 min): the sensitivity increased from 0.60 to 1.00, PPV from 0.75 to 0.83 and NPV from 0.89 to 1. This study, with caution for the small number of patients included, seems to suggest that 2P-PET/CT could increase the overall accuracy of EoT PET/CT in correctly classifying treatment response in HL with a persisting SFAM at EoT