Choriocarcinoma, a highly malignant trophoblastic tumor, usually follows a normal or abnormal pregnancy and is called gestational choriocarcinoma. The nongestational form, known as primary choriocarcinoma, is extremely rare in men. Herein, we report the 18F-FDG and 68Ga-FAPI-04 PET/CT findings in a 56-year-old man with nongestational choriocarcinoma of unknown primary and multiple metastases. The lesions showed intense 18F-FDG uptake but limited 68Ga-FAPI-04 accumulation.

Solitary fibrous tumor (SFT) is a mesenchymal tumor with unpredictable biological behavior that can occur in multiple anatomic sites throughout the body. This case report describes a 22-year-old man with an intracranial malignant solitary fibrous tumor. After 3 courses of 177 Lu-FAP-2286 therapy, 68 Ga-FAP-2286 PET/CT revealed partial tumor regression, with the patient reporting no adverse reactions.

To investigate the association between baseline NETPET score and prognosis in patients with neuroendocrine tumors (NETs) receiving [225Ac]Ac-DOTATATE therapy. This retrospective study included patients with NETs treated with [225Ac]Ac-DOTATATE between November 2021 and March 2025. All patients underwent [18F]F-FDG and [68Ga]Ga-DOTATATE PET within one week before treatment. Up to 10 representative lesions per patient were selected for NETPET scoring. The primary endpoint was progression-free survival (PFS). The relationship between NETPET score and PFS was evaluated using Kaplan–Meier analysis and univariate/multivariate Cox proportional hazards models. Forty-eight patients were enrolled (P1: n = 14, P2–4: n = 22, P5: n = 12). The P1 group achieved significantly better PFS than the P2-4 and P5 groups (2-year PFS rates: 0.83 vs. 0.32 vs. 0.10; log-rank P < 0.0001). Univariate analysis revealed a significant association of NETPET score with PFS (P2–4 vs. P1: HR = 7.07, P = 0.009; P5 vs. P1: HR = 17.0, P < 0.001). Multivariate analysis demonstrated the NETPET score to be independently associated with PFS (P2–4 vs. P1: P = 0.003; P5 vs. P1: P < 0.001). Its predictive value for overall survival was limited (P > 0.05). The NETPET score was independently associated with progression-free survival and may serve as a potential imaging biomarker for pretreatment risk stratification in NET patients receiving [225Ac]Ac-DOTATATE therapy.

To develop a FAP-FDG integrated score (FFIS) based on [68Ga]Ga-FAP-2286 and [18F]F-FDG PET/CT, and evaluate its prognostic value for risk stratification compared to conventional single-parameter imaging. This retrospective study included 193 patients with solid tumors who underwent both [18F]F-FDG and [68Ga]Ga-FAP-2286 PET/CT scans. Overall survival (OS) was the primary endpoint. The FFIS score was constructed by analyzing the uptake intensity and patterns of both radiotracers. Survival analysis employed the Kaplan-Meier method. The prognostic predictive value of FFIS, FDG-SUVmax, and FAP-SUVmax was evaluated using univariate and multivariate Cox proportional hazards models and compared with other clinical variables. Finally, subgroup analysis and interaction tests explored the prognostic consistency of FFIS, FDG-SUVmax, and FAP-SUVmax across different subgroups. FFIS emerged as an independent predictor of OS in both univariate (HR = 1.79, P < 0.001) and multivariate (HR = 1.75, P < 0.001) analyses. A higher FFIS reliably predicted worse survival: no deaths occurred among patients of score 1, whereas the median OS was 36, 13, and 8 months for scores 2, 3, and 4, respectively (Log-Rank P < 0.0001). This prognostic stratification remained consistent nearly all clinical subgroups (P-interaction > 0.05). In contrast, FDG-SUVmax showed no independent prognostic value, and FAP-SUVmax was predictive only in univariate analysis (HR = 1.04, P = 0.03). By integrating metabolic and stromal information, the FFIS may offer preliminary prognostic value across solid tumors.

Programmed death-ligand 1 (PD-L1) is highly expressed in tumour cells and the tumour microenvironment, mediates tumour immune evasion, and is a key target for cancer immunotherapy. Immunohistochemistry (IHC), as a conventional method for PD-L1 detection, has limitations such as invasiveness, temporal and spatial heterogeneity, and an inability to provide dynamic monitoring. In contrast, PD-L1-targeted molecular imaging enables non-invasive, quantitative, and whole-body visual assessment of PD-L1 expression, offering a precise tool for patient selection, treatment response prediction and dynamic monitoring in immunotherapy, and has thus become a focal point in precision oncology research. This paper systematically reviews the development trajectory of PD-L1-targeting radiotracers, including monoclonal antibodies, peptides, nanobodies, aptamers and small molecules. It summarises the targeting performance, pharmacokinetics, imaging efficacy and safety in preclinical and clinical studies; compares the advantages and suitable applications of different types of tracers; analyses the challenges currently facing the field, such as the lack of evaluation standards, tumour heterogeneity, insufficient clinical translation and a scarcity of multicentre data; and offers a prospect on the standardisation of PD-L1-targeted molecular imaging, the integration of diagnosis and treatment, multimodal imaging and its promotion and application in primary care settings. To date, more than 40 PD-L1-targeting tracers have undergone preclinical or clinical validation, with non-invasive imaging demonstrated to be feasible in over 100 cancer patients; early data support further in-depth research and clinical translation in this field.

OBJECTIVES:This study was developed with the primary goal of assessing any potential correlations between [68Ga]Ga -FAPI-04 PET/CT-derived parameters and the overall and progression-free survival (OS and PFS) of patients with soft tissue sarcoma (STS). The association between sarcomatous lesional uptake and FAP immunohistochemistry (IHC) results was also examined. METHODS:Patients with a primary STS diagnosis who underwent [68Ga]Ga-FAPI-04 PET/CT were retrospectively evaluated. Basic information included age, gender, tumor size location, necrosis volume, and [68Ga]Ga-FAPI-04 PET/CT-based parameters included maximum tumor standardized uptake value (SUVmax), FAPI-avid tumor volume (FTV), and total lesion FAP expression (TLF). Prognostic outcomes were analyzed using Kaplan-Meier curves and Cox regression. Spearman's correlation was used to examine the association between [68Ga]Ga-FAPI-04 uptake and FAP expression. RESULTS:Survival analyses included 22 patients, of whom 10 underwent FAP IHC staining. A significant association was observed between FAP levels and SUVmax for these STS patients (r = 0.88, P < 0.001). In univariate analyses, FTV and TLF were both significantly correlated with OS and PFS (P < 0.05). SUVmax, in contrast, was only correlated with patient OS. FTV and TLF values were established as significant independent predictors of PFS (HR = 4.15, P = 0.01) and OS (HR = 4.12, P = 0.02). In addition, a roughly 3-fold greater risk of progression was also noted for patients with a tumor necrosis volume exceeding 50% relative to patients below this threshold. CONCLUSION:FAP expression is significantly correlated with [68Ga]Ga-FAPI-04 uptake and pre-treatment [68Ga]Ga-FAPI-04 PET/CT parameters can predict survival outcomes for STS patients. ADVANCES IN KNOWLEDGE:Clinical utility of [68Ga]Ga-FAPI-04 in STS remains unclear, and there aren't many similar studies in the literature. We evaluated the role of [68Ga]Ga-FAPI-04 in the prognosis of STS.

To evaluate the efficacy and safety of [225Ac]Ac-DOTATATE therapy in neuroendocrine neoplasms (NENs) with high somatostatin receptor (SSTR) expression. Retrospective analysis was conducted in NENs who demonstrated high SSTR expression on [68Ga]Ga-DOTATATE PET/CT and received [225Ac]Ac-DOTATATE therapy. Response was assessed by RECIST 1.1 and PERCIST 1.0 criteria. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method. Toxicities were graded according to CTCAE v5.0. Thirty-one patients were included. Partial response (PR) and partial molecular response (PMR) were observed in 19.4

To improve the theranostic efficacy of PSMA-targeted radiopharmaceuticals on patients with medium-to-low PSMA expression, we radiolabeled a series of novel designed PSMA-targeting dimer agents to improve tumor imaging and treatment outcomes under challenging conditions. All agents were successfully radiolabeled with 68Ga in moderate decay-corrected labeling yield and high radiochemical purity. Among them, [68Ga]Ga-TVS-PSMA-1 exhibited high tumor uptake in both LNCaP and 22RV1 models. [177Lu]Lu-TVS-PSMA-1 demonstrated significantly improved treatment efficacy with a lower dose and good safety profile compared with [177Lu]Lu-PSMA-617. A first-in-human [68Ga]Ga-TVS-PSMA-1 PET/CT scan was performed in a 66-year-old male prostate cancer patient. Two metastatic lesions in the lumbar vertebrae were clearly visualized, and the primary tumor exhibited an SUVmax of 30.3. The [68Ga]Ga-TVS-PSMA-1 showed lower salivary gland uptake compared with previously reported values for [68Ga]Ga-PSMA-11; however, confirmation in larger patient cohorts is required. This study demonstrates that the dimer agent TVS-PSMA-1 holds great potential as a next-generation theranostic agent for prostate cancer.

A 54-year-old man with progressive small cell lung cancer underwent ¹⁸F-FDG and ⁶⁸Ga-DOTATATE PET/CT before radionuclide therapy. ¹⁸F-FDG PET/CT evaluated disease extent and identified metabolically active lesions. ⁶⁸Ga-DOTATATE PET/CT showed high SSTR expression in bone lesions and the pancreatic tail. Discordant hepatic uptake suggested tumor heterogeneity. The two scans provided complementary information on disease activity and therapeutic target expression, supporting patient selection and individualized planning for an SSTR-targeted radionuclide therapy-based comprehensive treatment strategy.

Standardized lesion segmentation on 68Ga-Pentixafor PET-CT is lacking in multiple myeloma (MM), and it is unclear how different segmentation methods affect semi-quantitative PET features. This study aimed to evaluate semi-automatic segmentation strategies and their impact on total lesion expression of C-X-C chemokine receptor type 4 (TLECXCR4) quantification and prognostic value. We retrospectively analyzed 68Ga-Pentixafor PET-CT scans from 49 newly diagnosed MM patients. Skeletal volume of interest was automatically delineated using an AI-based tool, and six semi-automatic segmentation approaches were applied using SUV thresholds based on liver, spleen, and bone uptake. Quality scores for lesion coverage, non-target inclusion, and contour fit were assessed. TLECXCR4 and other parameters were compared, and their associations with bone marrow plasma cell infiltration and 3-year disease progression were analyzed. Segmentation performance varied widely. The liver2× approach achieved the best balance between lesion coverage and non-target marking. TLECXCR4 from all approaches correlated moderately with bone marrow infiltration (ρ = 0.31–0.54), and strongly with visual staging (ρ = 0.77–0.88, except for bone40

Background Pheochromocytomas and paragangliomas (PPGLs) frequently overexpress somatostatin receptor subtype 2 (SSTR2), making [ 68 Ga]Ga-DOTATATE PET/CT a promising functional imaging modality. However, the optimal interpretation criteria for distinguishing PPGL from non‑PPGL lesions in clinically suspected adrenal or retroperitoneal masses remain undefined. This retrospective study evaluated the diagnostic performance of [ 68 Ga]Ga-DOTATATE PET/CT using three interpretation criteria: Integrated Interpretation (combining PET/CT metabolic patterns, CT morphology, and clinical information), Liver Threshold Interpretation (lesion SUV max ≥ liver SUV mean ), and Blood‑Pool Threshold Interpretation (lesion SUV max ≥ 5 × blood‑pool SUV mean ). Thirty‑six patients with suspected adrenal or retroperitoneal PPGL underwent [ 68 Ga]Ga-DOTATATE PET/CT; all target lesions were histopathologically confirmed. Sensitivity, specificity, accuracy, and ROC analyses were performed. Results Histopathology confirmed PPGL in 22 patients (18 adrenal, 4 extra‑adrenal) and non‑PPGL in 14 patients. The Liver Threshold Interpretation achieved 100% sensitivity (22/22), 78.6% specificity (11/14), and 91.7% accuracy (33/36), significantly outperforming the Integrated Interpretation in sensitivity (100% vs. 77.3%, P = 0.018), negative predictive value (100% vs. 70.6%, P = 0.047), and accuracy (91.7% vs. 80.6%, P < 0.001). The AUC of Liver Threshold (0.893) was significantly larger than those of Integrated (0.815, P = 0.042) and Blood‑Pool (0.714, P = 0.014). Optimal cutoffs were SUV max ≥ 6.95 (AUC 0.893) and lesion‑to‑liver ratio ≥ 0.95 (AUC 0.893). PPGL lesions showed higher SUV max (24.4 ± 19.1 vs. 5.3 ± 3.5, P = 0.001) and smaller volumes. The ‘target sign’ (ring‑like peripheral uptake) was more frequent in PPGLs (45.5% vs. 7.1%, P = 0.025). Conclusion [ 68 Ga]Ga-DOTATATE PET/CT demonstrates high diagnostic accuracy in distinguishing PPGL from non‑PPGL lesions in clinically suspected adrenal or retroperitoneal masses. The Liver Threshold Interpretation is a practical screening tool with 100% sensitivity and 91.7% accuracy. Optimal semiquantitative cutoffs (lesion SUV max ≥ 6.95 or lesion‑to‑liver ratio ≥ 0.95) provide reliable discrimination.

Pheochromocytomas and paragangliomas (PPGLs) frequently overexpress somatostatin receptor subtype 2 (SSTR2), making [68Ga]Ga-DOTATATE PET/CT a promising functional imaging modality. However, the optimal interpretation criteria for distinguishing PPGL from non-PPGL lesions in clinically suspected adrenal or retroperitoneal masses remain undefined. This retrospective study evaluated the diagnostic performance of [⁶⁸Ga]Ga-DOTATATE PET/CT by systematically comparing three interpretation criteria: Integrated Interpretation (combining PET/CT metabolic patterns, CT morphology, and clinical information), Liver Threshold Interpretation (lesion SUVmax ≥ liver SUVmean), and Blood-Pool Threshold Interpretation (lesion SUVmax ≥ 5 × blood-pool SUVmean). Thirty-six patients with suspected adrenal or retroperitoneal PPGL underwent [68Ga]Ga-DOTATATE PET/CT; all target lesions were histopathologically confirmed. Sensitivity, specificity, accuracy, and ROC analyses were performed. Histopathology confirmed PPGL in 22 patients (18 adrenal, 4 extra-adrenal) and non-PPGL in 14 patients. The Liver Threshold Interpretation achieved 100

The efficacy of the combination of hyperbaric oxygen therapy and the radionuclide treatment in targeting and treating metastatic bone pain due to tumors was analyzed in this study. Thirty-nine patients with metastatic bone tumors were divided into 2 groups. Group A consisted of patients receiving hyperbaric oxygen therapy combined with radionuclide therapy, and group B had patients receiving radionuclide therapy alone. Pain scores, sleep scores before and after treatment and the proportion of patients whose analgesic dosage was reduced within 24 h in both groups were analyzed at different time points before and after drug administration, and the scores between the groups were compared. All patients received 1 session of radionuclide therapy, with patients in group A receiving in combination with 1 course of hyperbaric oxygen therapy. On the seventh day after treatment, patients in Group A exhibited significantly lower pain scores than those in Group B, particularly during the initial 48 h. On day 30 post-treatment, sleep scores decreased in both patient groups. After 7 days of treatment, the proportion of patients in Group A and Group B experiencing painkiller reduction at different time points 24 h was 72.2% and 42.9%, respectively. There were no significant differences in bone marrow suppression status and renal function measurements between the two groups of patients before and after treatment. Hyperbaric oxygen combined with radionuclide therapy is safe and provides faster relief of bone pain in patients with bone metastases. Hyperbaric oxygen therapy can enhance the therapeutic effect of radionuclide therapy, and this combination warrants further evaluation for potential use in a clinical setting.

Building upon our previous work on [68Ga]Ga/[177Lu]Lu-DOTA-Ibandronate and its demonstrated clinical applicability, this study investigates the biological behavior and translational potential of the novel therapeutic radiopharmaceutical terbium-161 (161Tb)-labeled DOTA-IBA. The radiolabeling parameters of [161Tb]Tb-DOTA-IBA were first optimized, followed by a systematic assessment of its physicochemical characteristics. Biodistribution, micro-SPECT/CT imaging, and therapeutic efficacy were evaluated in a 4T1 mouse model of bone metastasis to determine pharmacokinetics and bone-targeting capacity. Safety was verified through dose-escalation experiments. Furthermore, a preliminary clinical evaluation was performed in one volunteer with bone metastases to validate safety and initial therapeutic efficacy. [161Tb]Tb-DOTA-IBA was obtained with radiochemical purity exceeding 98%, demonstrating excellent bone-targeting selectivity and retention, with a 24 h bone uptake of 30.61 ± 4.61% ID/g, which is substantially higher than in soft tissues. In a patient receiving 370 MBq, marked pain relief was achieved, reflected by decreased VAS scores, with therapeutic benefit lasting 8-12 weeks and no observed toxic reactions. The compound exhibited favorable pharmacokinetics and safety, with no ≥ grade 3 adverse events. Overall, [161Tb]Tb-DOTA-IBA displayed high tumor-to-background ratios and excellent pharmacokinetic behavior. Early human data confirmed its safety and therapeutic potential. The complementary use of [68Ga]Ga/[161Tb]Tb-DOTA-IBA enables a unified diagnostic-therapeutic platform for the management of bone metastases, providing an innovative, targeted treatment option capable of improving both quality of life and survival in patients with advanced skeletal disease.

Pheochromocytomas and paragangliomas (PPGLs) frequently overexpress somatostatin receptor subtype 2 (SSTR2), making [68Ga]Ga-DOTATATE PET/CT a promising functional imaging modality. However, the optimal interpretation criteria for distinguishing PPGL from non-PPGL lesions in clinically suspected adrenal or retroperitoneal masses remain undefined. This retrospective study evaluated the diagnostic performance of [⁶⁸Ga]Ga-DOTATATE PET/CT by systematically comparing three interpretation criteria: Integrated Interpretation (combining PET/CT metabolic patterns, CT morphology, and clinical information), Liver Threshold Interpretation (lesion SUVmax ≥ liver SUVmean), and Blood-Pool Threshold Interpretation (lesion SUVmax ≥ 5 × blood-pool SUVmean). Thirty-six patients with suspected adrenal or retroperitoneal PPGL underwent [68Ga]Ga-DOTATATE PET/CT; all target lesions were histopathologically confirmed. Sensitivity, specificity, accuracy, and ROC analyses were performed. Histopathology confirmed PPGL in 22 patients (18 adrenal, 4 extra-adrenal) and non-PPGL in 14 patients. The Liver Threshold Interpretation achieved 100

Chordoma is a rare malignant bone tumor derived from notochordal remnants, typically occurring in the axial skeleton. Herein, we report a case of an 81-year-old woman with a cervical chordoma involving the C1-C5 vertebrae. The lesion demonstrated intense 18 F-FDG uptake but minimal 68 Ga-DOTA-FAPI-04 accumulation. This discordant imaging pattern highlights that while FAPI-targeted PET/CT is a promising pan-cancer imaging modality, its uptake in chordoma may be heterogeneous, potentially influenced by the tumor microenvironment or specific histologic subtypes.

Sclerosing epithelioid fibrosarcoma is extremely rare and aggressive soft-tissue sarcoma. Here, we report the 68Ga-DOTA-IBA PET/CT findings in a case with sclerosing epithelioid fibrosarcoma with bone metastases. 68Ga-DOTA-IBA PET/CT revealed increased uptake of DOTA-IBA in bone metastases. Unexpectedly, 68Ga-DOTA-IBA uptake was also observed in the primary sclerosing epithelioid fibrosarcoma in the abdomen.

Background Current bone metastasis evaluation relies on fragmented anatomic or metabolic criteria, often yielding discordant classifications. Purpose To develop Response Evaluation Criteria in Bone Metastases (termed RECIBM) and evaluate its performance against the University of Texas MD Anderson Cancer Center, PET Response Criteria in Solid Tumors (PERCIST), and European Organisation for Research and Treatment of Cancer (EORTC) criteria. Materials and Methods This retrospective study was conducted between October 2017 and September 2023. RECIBM was established based on multidisciplinary consensus and assessed on real-world patient data, with treatment responses evaluated using RECIBM, MD Anderson, PERCIST, and EORTC criteria. The paired subgroup comprised patients evaluable by all four criteria; the remaining patients underwent technetium 99m methylene diphosphonate bone scintigraphy only and were evaluable using the MD Anderson criteria and RECIBM. Agreement was quantified using the Cohen κ value, and prognostic performance for overall survival and bone progression-free survival was assessed using the Harrell C-index and multivariable Cox regression. Results Eighty-four patients (median age, 59.0 years [IQR, 52.0-68.3 years]; 59 male) were included. RECIBM-defined response classifications demonstrated high agreement with those of existing criteria (κ = 0.80-0.98; all P < .001) and reclassified 19% of patients (16 of 84). In the paired subgroup, RECIBM showed the highest C-index for overall survival (0.807 vs 0.771-0.782; P = .10-.14) and bone progression-free survival (0.849 vs 0.799-0.833; raw P = .03-.26; adjusted P = .088-.256), with no evidence of differences after adjustment. Subgroup analyses showed consistent performance across different imaging modalities and tumor types (P for interaction = .39 and .051, respectively). In multivariable analysis, RECIBM-defined response was associated with overall survival (hazard ratio, 0.07 [95% CI: 0.03, 0.19]; P < .001) and bone progression-free survival (hazard ratio, 0.03 [95% CI: 0.01, 0.08]; P < .001). Conclusion RECIBM-defined response classifications showed high agreement with established criteria, reclassified 19% of patients, and were associated with overall survival and bone progression-free survival. © RSNA, 2026 Supplemental material is available for this article. See also the editorial by Mohammadi and Guermazi in this issue.

NUT carcinoma is a rare and highly aggressive tumor with nuclear protein in the testis gene rearrangement. Herein, we describe the different findings of 68 Ga-FAPI-04 and 18 F-FDG PET/CT in a 31-year-old man with mediastinal NUT carcinoma with lymph node and pleura metastasis. In our case, 68 Ga-FAPI-04 PET/CT was not superior to FDG in detecting primary lesions and lymph node metastases of mediastinal NUT, but it is possible to produce beneficial value in the evaluation of pleura metastasis.