Shallow-depth sequencing of cell-free DNA for Hodgkin and diffuse large B-cell lymphoma (differential) diagnosis: a standardized approach with underappreciated potential.

Shallow-depth sequencing of cell-free DNA, a cheap and standardized approach to obtain molecular information on tumors non-invasively, is insufficiently explored for lymphoma diagnosis and disease follow-up. This study collected 318 samples, including longitudinal liquid and paired solid biopsies, from a prospectively recruited cohort of 38 Hodgkin lymphoma (HL) and 85 aggressive B-cell non- HL patients, represented by 81 diffuse large B-cell lymphoma (DLBCL) cases. Following sequencing, copy number alterations and viral read fractions were derived and analyzed. At diagnosis, liquid biopsies showed detectable copy number alterations in 84.2% of HL (88.6% for classical HL) and 74.1% of DLBCL patients. Copy number profiles between liquid-solid pairs were highly concordant within DLBCL (r=0.815±0.043); and, compared to tissue, HL liquid biopsies had abnormalities with higher amplitudes (P=.010), implying that tumor DNA is more abundant in plasma. Additionally, 39.5% of HL and 13.6% of DLBCL cases had a significantly elevated number of plasmatic Epstein-Barr virus DNA fragments, achieving a sensitivity of 100% compared to current standard. Longitudinal analysis determined that, when detectable, copy number patterns were similar across (re)staging moments in refractory/relapsed patients. Moreover, the overall profile anomaly highly correlated with the total metabolic tumor volume (P.

Clinical impact of using [18F]AlF-NOTA-octreotide PET/CT instead of [68Ga]Ga-DOTA-SSA PET/CT: Secondary endpoint analysis of a multicenter, prospective trial.

[18F]AlF-NOTA-octreotide ([18F]AlF-OC) is a promising alternative for [68Ga]Ga-DOTA-somatostatin analogs (SSAs) in positron emission tomography (PET) imaging of the somatostatin receptor (SSTR). Our aim is to assess changes in TNM staging and differences in patient management between [18F]AlF-OC PET/CT and [68Ga]Ga-DOTA-SSA PET/CT in the work-up of neuroendocrine tumor (NET) patients. Patients who underwent both [18F]AlF-OC and [68Ga]Ga-DOTA-TATE or [68Ga]Ga-DOTA-NOC PET/CT in our multicenter study (Pauwels et al., J Nucl Med.2023;63:632-638) with a NET were included for analysis. TNM staging was determined and compared for both tracers. For each patient, the blinded [68Ga]Ga-DOTA-SSA or [18F]AlF-OC PET/CT images were presented in random order at a multidisciplinary team board. The images were presented together with clinical information and compared with previous SSTR and [18F]FDG PET/CT imaging. After a consensus decision for patient management was recorded, the board was presented with the PET/CT images from the other SSTR tracer and a decision was made for the second tracer. Differences in management were classified as major if it entailed an intermodality change and minor if it led to an intramodality change. Compared with [68Ga]Ga-DOTA-SSA, the use of [18F]AlF-OC led to a change in 16/75 patients: TNM staging changes in 10/75 patients (13.3%; downstaging in 3/10, upstaging in 7/10) and differences in clinical management were seen in 10/75 patients (13.3%), leading to a major difference in 7/10 cases and a minor change in 3/10 cases. All 10 cases with a difference in patient management between both PET tracers were caused by additional lesion detection by [18F]AlF-OC. The use of [18F]AlF-OC did not impact TNM staging or clinical management in the large majority of the patients (86.7%), further validating the potential for routine clinical use of [18F]AlF-OC PET/CT as an alternative for [68Ga]Ga-DOTA-SSA PET/CT. The trial is registered under ClinicalTrials.gov identifier NCT04552847 and EudraCT 2020-000549-15.

Impact of 18F-PSMA-11 PET/CT on Management of Biochemical Recurrence and High-Risk Prostate Cancer Staging : 18F-PSMA-11 PET/CT and Impact on Prostate Cancer Management.

PURPOSE: In this study, we evaluated the impact of 18F-PSMA-11 PET/CT on the patient management plan in patients with primary or recurrent disease. Furthermore, a correlation between PET findings and other modalities was performed. PROCEDURES: In this prospective observational study, 60 prostate cancer patients (9 primary staging, 51 biochemical recurrence) were imaged with 18F-PSMA-11 PET/CT. Pre- and post-scan questionnaires were completed by the treating physician to observe changes in therapy intent. Follow-up data (histological confirmation, MRI imaging, and PSA values after radiotherapy without implementation of systemic therapy) was correlated with the 18F-PSMA-11 findings. RESULTS: The patient-based detection rate was 82% and a management change was seen in 52% of the cases. The heterogeneous characteristics of the included patients resulted in a widely varying treatment change, mostly originating from an increase of disease extent on 18F-PSMA-11 PET/CT. CONCLUSION: 18F-PSMA-11 PET/CT showed to be a highly promising method for the detection of prostate cancer lesions.

Hybrid imaging of complicating osteomyelitis in the peripheral skeleton.

Diagnosing complicating osteomyelitis (COM) is clinically challenging. Laboratory tests are of limited utility, and other than isolation of the offending organism, diagnostic imaging tests are of paramount importance. Nuclear Medicine techniques play an important role in noninvasive evaluation of osteomyelitis, using both single-photon emission tomography (SPECT) and positron emission tomography (PET) radiopharmaceuticals. It is well-known that those conventional imaging modalities are not performing well in the distinction between soft-tissue and deep bone infection due to the lack of anatomical information. These difficulties have been overcome, to a great extent, with the introduction of in-line SPECT-CT and PET-CT systems which have revolutionized the field of diagnostic medical imaging. Hybrid imaging is especially useful in sites of suspected COM with underlying structural bone alterations. The first clinical studies with these integrated hybrid machines in the field of COM, including metallic implants imaging, are highly promising. In summary, WBC/AGA SPECT-CT and FDG-PET-CT seem to be the most accurate hybrid imaging modality for COM of the peripheral bone. However, there are still false positives, especially in aseptic tibial nonunions and/or metallic implants, as well as in the immediate postoperative setting. Furthermore, there is a lack of well-designed large multicentre prospective studies. Hopefully, in the future, the complementary use of morphological and functional hybrid imaging modalities may overcome some of the challenges faced in the assessment of COM.

Spatiotemporal Evolution of Radiation Myositis on 18F-FDG PET/CT Following Hypofractionated Radiotherapy of Intramuscular Melanoma Metastases.

ABSTRACT: Radiation myositis is an infrequent late adverse effect of radiotherapy (RT), more commonly seen after hypofractionated regimens. We present the case of a 52-year-old woman with oligorecurrent metastatic melanoma who, several months after receiving local hypofractionated RT, developed a painful swelling at the irradiated site. As an integral part of routine oncologic follow-up, 18F-FDG PET/CT allowed accurate visualization of the affected region and when matched with RT treatment plans clearly illustrated their apparent overlap. This case demonstrates the utility of 18F-FDG PET/CT in the early detection and monitoring of radiation myositis and highlights the importance of a multidisciplinary approach in melanoma care.

Parathyroid Adenoma Mimicking a Malignant Lymph Node on 18F-Choline PET-CT.

Prostate carcinoma is the most common cancer in men. After local therapy, disease recurs in many patients. A choline PET/CT is indicated in case of biochemical relapse of prostate carcinoma to determine the site of recurrence (local and/or distant) and to help select the next line of therapy. Choline PET-CT is also known to show an elevated uptake in hyperfunctioning parathyroid adenoma. This case report shows the difficulty to distinguish between both entities if they occur simultaneously in an oncologic patient.