Purpose of the Report: The usefulness of brain ¹⁸F-FDG PET/CT in primary central nervous system lymphoma (PCNSL) remains underexplored. This study investigated whether early metabolic responses in interim brain FDG PET/CT serve as a prognostic indicator of PCNSL treatment outcomes. Patients and Methods: This prospective study included 53 patients with PCNSL who underwent a high-dose methotrexate–based treatment. Brain FDG PET was performed at diagnosis (baseline PET) and after induction chemotherapy (interim PET), assessing interim PET parameters such as the highest maximum standardized uptake value (hSUV_max), sum of SUV_max (sumSUV_max), highest tumor-to-normal ratio (hTNR_max), sum of TNR_max (sumTNR_max), highest metabolic tumor volume (MTV) (hMTV), and sum of MTV (sumMTV) across all PET-positive lesions. Results: High interim hTNR_max (hazards ratio: 9.76, 95% confidence interval: 1.90–50.11, P = 0.01) was an independently significant predictor of poor progression-free survival in multivariate analysis. Patients with low interim hTNR_max (≤1.0) had a significantly longer median progression-free survival than those with high interim hTNR_max (>1.0) (25.0 vs 3.6 months, P < 0.001). Incorporating interim MRI-based clinical response assessments and hTNR_max allowed the classification of partial response subgroups with markedly different prognoses (P < 0.001). High interim hTNR_max (hazards ratio: 2.76, 95% confidence interval: 1.39–5.48, P = 0.004) was an independently significant predictor of poor overall survival in multivariate analysis. Conclusions: The hTNR_max measurement from interim brain FDG PET scans emerges as an important prognostic marker in PCNSL. These findings underscore the potential of interim FDG PET evaluations to refine response assessments and inform tailored therapeutic strategies.

Background/Objectives: Circulating tumor DNA (ctDNA) has emerged as a promising biomarker for non-invasive tumor monitoring in diffuse large B-cell lymphoma (DLBCL). Methods: In this study, 52 patients with newly diagnosed advanced-stage DLBCL treated with R-CHOP underwent serial ctDNA analysis at baseline, interim (after three cycles), and end of treatment. The prognostic significance of ctDNA dynamics was evaluated, and its predictive value was compared with the PET/CT response. Results: Targeted next-generation sequencing revealed baseline ctDNA in 98.1% of patients, with 74.7% concordance to tumor tissue genotyping. Higher baseline ctDNA levels correlated with elevated LDH, older age, and high IPI scores. A ≥2-log reduction in ctDNA at interim was significantly associated with improved overall survival (p = 0.004), though not with progression-free survival. Notably, combining interim ctDNA dynamics with PET/CT results enhanced the predictive accuracy for treatment outcomes, particularly among patients with partial metabolic responses. Conclusions: These findings support the clinical utility of ctDNA for dynamic risk assessment in DLBCL, and suggest that integrating ctDNA with imaging biomarkers may guide more personalized therapeutic strategies. Further validation using highly sensitive ctDNA assays is warranted to optimize its role in routine clinical practice.

DongGeun Son, M.D., Ho Cheol Jang, M.D., Young Eun Lee, Ph.D., Yong Jun Choi, M.D., Joo Heon Park, M.D., Ha Jin Lim, M.D., Hyun-Jung Choi, M.D., Ph.D., Hee Jo Baek, M.D., Ph.D., Hoon Kook, M.D., Ph.D., Mihee Kim, M.D., Ph.D., Ga-Young Song, M.D., Ph.D., Seo-Yeon Ahn, M.D., Ph.D., Sung-Hoon Jung, M.D., Ph.D., Deok-Hwan Yang, M.D., Ph.D., Je-Jung Lee, M.D., Ph.D., Hyeonug-Joon Kim, M.D., Ph.D., Jae-Sook Ahn, M.D., Ph.D., and Myung-Geun Shin, M.D., Ph.D.. Ann Lab Med -0001;0:. https://doi.org/10.3343/alm.2024.0570

Kim M, et al. J Korean Med Sci. 2021 Nov;37(1):e2. https://doi.org/10.3346/jkms.2022.37.e2

Cancer remains a leading cause of mortality worldwide. Chemotherapy is effective but can cause febrile neutropenia, deplete neutrophils, and increase infection risk. Although timely fever detection is critical to prevent complications, periodic temperature monitoring has inherent limitations. Wearable devices (WDs) for real-time body temperature (RBT) monitoring are emerging as tools for early fever detection, though their clinical feasibility and usability remain unverified. This study assessed the clinical feasibility of a novel WD by comparing its temperature concordance and fever detection capability against a standard reference in patients with cancer. The RBT system’s clinical maturity, including its capacity for early fever detection and monitoring treatment-related changes, was evaluated. Furthermore, satisfaction among clinicians and patients was analyzed in a hospital setting. In this prospective study, patients with hematologic malignancies at high infection risk admitted to the Chonnam National University in Hwasun Hospital, South Korea, were enrolled. Data from 47 patients were analyzed to compare MT100D as WD (SEERS Technology Co., Ltd., South Korea) readings with axillary thermometers. Temperature concordance was evaluated using the intraclass correlation coefficient (ICC), and diagnostic performance was compared with the reference thermometer. The early fever detection performance of the MT100D was analyzed to evaluate the clinical effectiveness of the early response system. Usability was evaluated through a five-point Likert scale survey completed by clinical nurses. The MT100D demonstrated good agreement with the reference thermometer (mean difference: −0.19 ± 0.35 °C; ICC: 0.78). The RBT system achieved sensitivity, specificity, and area under the receiver operating characteristic curve values of 81.50%, 96.32%, and 96.60%, respectively. The early fever detection rate was 77.1%, with the RBT system detecting fever an average of 1.13 ± 1.28 h earlier than the reference. Usability and satisfaction assessments showed high patient satisfaction (mean 4.69 ± 0.5; range 4.57–4.80) and moderate clinician satisfaction (mean 3.63 ± 0.75; range 2.89–4.11). Among patients with cancer, including those at risk of febrile neutropenia, the MT100D demonstrated strong concordance with standard thermometry, enabling early fever detection. The RBT system shows promise for the early identification of neutropenic risk during chemotherapy.