Observations of Oncologists on Treatment Selection With Interim Positron Emission Tomography-Adapted Approaches in Classic Hodgkin Lymphoma: The Real-World CONNECT Study

Enhancing the Diagnostic Utility of ASL Imaging in Temporal Lobe Epilepsy through FlowGAN: An ASL to PET Image Translation Framework

Background and Significance

Positron Emission Tomography (PET) using fluorodeoxyglucose (FDG-PET) is a standard imaging modality for detecting areas of hypometabolism associated with the seizure onset zone (SOZ) in temporal lobe epilepsy (TLE). However, FDG-PET is costly and involves the use of a radioactive tracer. Arterial Spin Labeling (ASL) offers an MRI-based quantification of cerebral blood flow (CBF) that could also help localize the SOZ, but its performance in doing so, relative to FDG-PET, is limited. In this study, we seek to improve ASL's diagnostic performance by developing a deep learning framework for synthesizing FDG-PET-like images from ASL and structural MRI inputs.

Methods

We included 68 epilepsy patients, out of which 36 had well lateralized TLE. We compared the coupling between FDG-PET and ASL CBF values in different brain regions, as well as the asymmetry of these values across the brain. We additionally assessed each modality's ability to lateralize the SOZ across brain regions. Using our paired PET-ASL data, we developed FlowGAN, a generative adversarial neural network (GAN) that synthesizes PET-like images from ASL and T1-weighted MRI inputs. We tested our synthetic PET images against the actual PET images of subjects to assess their ability to reproduce clinically meaningful hypometabolism and asymmetries in TLE.

Results

We found variable coupling between PET and ASL CBF values across brain regions. PET and ASL had high coupling in neocortical temporal and frontal brain regions (Spearman's r > 0.30, p < 0.05) but low coupling in mesial temporal structures (Spearman's r < 0.30, p > 0.05). Both whole brain PET and ASL CBF asymmetry values provided good separability between left and right TLE subjects, but PET (AUC = 0.96, 95% CI: [0.88, 1.00]) outperformed ASL (AUC = 0.81; 95% CI: [0.65, 0.96]). FlowGAN-generated images demonstrated high structural similarity to actual PET images (SSIM = 0.85). Globally, asymmetry values were better correlated between synthetic PET and original PET than between ASL CBF and original PET, with a mean correlation increase of 0.15 (95% CI: [0.07, 0.24], p<0.001, Cohen's d = 0.91). Furthermore, regions that had poor ASL-PET correlation (e.g. mesial temporal structures) showed the greatest improvement with synthetic PET images.

Conclusions

FlowGAN improves ASL's diagnostic performance, generating synthetic PET images that closely mimic actual FDG-PET in depicting hypometabolism associated with TLE. This approach could improve non-invasive SOZ localization, offering a promising tool for epilepsy presurgical assessment. It potentially broadens the applicability of ASL in clinical practice and could reduce reliance on FDG-PET for epilepsy and other neurological disorders.

Real-life study on the use of response adapted therapy in patients with Hodgkin Lymphoma: Results from a multicenter experience

Few data are known regarding the use of interim positron emission tomography (iPET) after the first two cycles (iPET2) of chemotherapy in treatment-naïve classical Hodgkin lymphoma (cHL) in routine clinical practice, and about the real-life adoption of intensification strategies for iPET positive patients. We conducted a multicenter retrospective study on cHL to investigate the use of iPET in the real-life setting, its prognostic role and outcomes of patients early shifted to intensification. Six hundreds and forty-one patients were enrolled (62% had advanced stage). iPET2 was positive in 89 patients (14%) including 8.7% and 17% early and advanced stage patients, respectively (p = 0.003). Among iPET 2 positive cases treatment was immediately modified in 19 cases; in 14 cases treatment was modified after an additional positive iPET4. Overall 56 iPET2 positive patients never received intensified therapies. Most frequently used intensified therapy was autologous stem cell transplantation followed by BEACOPP. After a median follow-up of 72 months, the 5-year progression-free survival (PFS) was 82% with iPET2 positive patients showing a worse PFS compared with iPET2 negative cases: 31% versus 85%. Focusing on advanced stage patients with a positive iPET2, the 5-year PFS was 59% for patients shifted to intensified therapy at any time point versus 61% for patients who never received intensified therapy. Our study confirmed the higher curability of naïve cHL patients in a real-world setting, and the prognostic role of iPET2 in this setting. A poor adherence to response-adapted strategy which however did not translate into a difference in patient outcomes.

Patient preferences in the treatment of stage III/IV classic Hodgkin lymphoma: Results from the CONNECT cross-sectional survey

We explored patient front-line treatment preferences in newly diagnosed stage III/IV classic Hodgkin lymphoma (cHL). The CONNECT patient survey, administered online from 30 December 2020 to 1 March 2021, examined preferences overall and by age at diagnosis in 182 adult patients diagnosed with stage III/IV cHL within the past 10 years in the United States. At diagnosis, patients' median age was 36 years; 66% of patients were younger (aged 16-41 years) and 34% older (aged 42-85 years). When asked about initial treatment goals, 74% of patients ranked cure as their first or second goal (86% younger vs. 52% older patients; p < 0.001). At diagnosis, 72% of patients preferred aggressive treatment, and 85% were willing to accept more short-term risks in exchange for a better-working therapy long term. For long-term risks, younger versus older patients were significantly more concerned about second cancers (p < 0.001) and fertility issues (p = 0.007), whereas older patients were more concerned about lung damage (p = 0.028) and infections (p < 0.001). Most patients (94%) reported having a caregiver at some point, but 99% of these patients retained some control of treatment decisions. Collectively, these survey results highlight patient treatment preferences and differences in treatment goals and long-term side effect concerns based on patient age.

Physician frontline treatment preferences for stage III/IV classic Hodgkin lymphoma: the real-world US CONNECT study

Aim: To understand US physicians' frontline (1L) treatment preferences/decision-making for stage III/IV classic Hodgkin lymphoma (cHL). Materials & methods: Medical oncologists and/or hematologists (≥2 years' practice experience) who treat adults with stage III/IV cHL were surveyed online (October-November 2020). Results: Participants (n = 301) most commonly considered trial efficacy/safety data and national guidelines when selecting 1L cHL treatments. Most physicians (91%) rated overall survival (OS) as the most essential attribute when selecting 1L treatment. Variability was seen among regimen selection for hypothetical newly diagnosed patients, with OS cited as the most common reason for regimen selection. Conclusion: While treatment selection varied based on patient characteristics, US physicians consistently cited OS as the top factor considered when selecting a 1L treatment for cHL.