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Abstract: Neuroblastoma is the most common malignancy in infants and the most common extracranial solid tumor accounting for approximately 6% of pediatric cancer. Although surgical intervention serves as the primary treatment for early-stage disease, advanced-stage cases necessitate a variety of oncologic therapeutic approaches, including 131I-MIBG and peptide receptor radionuclide therapy. Herein we report incidental pineal gland activity, represented in 68Ga-DOTATATE PET/CT (SSTR-PET) in 3 pediatric patients diagnosed with stage 4 neuroblastoma, related to the physiological distribution of radiopharmaceuticals., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We present a case with systemic amyloidosis secondary to immunoglobulin light-chain amyloidosis (AL amyloidosis), which 18F-FDG PET/CT and 99mTc-PYP scintigraphy revealed amyloid deposition in the peritoneum, omentum, and mesentery. AL amyloidosis is characterized by the proliferation of clonal plasma cells and increased production and extracellular accumulation of immunoglobulin light chains, leading to organ malfunction. Even though AL amyloidosis can affect the gastrointestinal system, peritoneal involvement is rarely observed. PET/CT and SPECT/CT images showed moderate to slightly increased tracer uptake in affected organs., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: We aimed to compare the diagnostic performance of 68Ga-FAPI-04 (FAPI) in comparison to 68Ga-DOTATATE (SSTR) PET/CT for patients presenting with recurrent medullary thyroid carcinoma (MTC)., Patients and Methods: Sixteen MTC patients with elevated calcitonin levels (>150 pg/mL) underwent FAPI and SSTR PET/CT. Two nuclear medicine physicians evaluated all images, categorizing lesions into locoregional metastases, mediastinal lymph nodes (LNs), liver, and bone metastases. SUVmax and tumor-to-background ratio were recorded. PET modalities were compared using the McNemar test. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FAPI and SSTR PET were calculated., Results: The cohort comprised 16 patients (50% female; mean age 50 ± 17 years). Median calcitonin and CEA levels were 6234 pg/mL and 17.3 ng/mL, respectively. In patient-based analysis, SSTR exhibited higher diagnostic sensitivity compared with FAPI (88% vs 81%), resulting a statistically significant difference (P = 0.004). Mean SUVmax and tumor-to-background ratio values were 10.3 and 5.35 for FAPI, and 9.7 and 11.9 for SSTR PET, respectively. In lesion-based analyses, FAPI demonstrated higher accuracy than SSTR for cervical LNs (91.9% vs 50%), mediastinal LNs (94.9% vs 54.4%), and liver metastases (57.4% vs 7.3%), respectively. Notably, 31% of patients (n = 5) with FAP-expressing liver lesions showed no uptake on SSTR imaging. MRI confirmed liver metastases in 3 of these patients; however, 2 FAP-expressing lesions were confirmed as hemangiomas. False-positive findings of DOTA primarily included reactive LNs and bone hemangiomas., Conclusions: FAPI PET presents promising outcomes in detecting metastases in recurrent MTC patients. Although its diagnostic performance matches SSTR on a per-patient basis, FAPI PET exhibits superior sensitivity and accuracy in lesion-based analyses, notably for liver and bone metastases., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Amyloidosis is a misfolded protein deposition disorder within the extracellular matrix, leading to dysfunction in the affected organ. Primary amyloidosis manifests as AL and ATTR subtypes, wherein AL is associated with plasma cell dyscrasias. Herein we present a case of a patient who underwent investigation due to the presence of bilateral reticulonodular lung infiltrates, suggestive of miliary tuberculosis. 99m Tc-PYP scan revealed widespread radiotracer uptake in the lungs leading to diagnosis of AL amyloidosis., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 69-year-old woman with breast cancer underwent 18 F-FDG PET/CT because of the increased CA-15-3 level. 18 F-FDG PET/CT showed multiple hypermetabolic lymph nodes (LNs) in the neck and mediastinum. The patient was also referred for 68 Ga-fibroblast activation protein inhibitor (FAPI) 04 PET/CT for further evaluation. However, 18 F-FDG-avid LNs were FAPI-negative on 68 Ga-FAPI-04 PET/CT. Supraclavicular LN biopsy confirmed the metastasis of breast cancer. Recent reports have focused on the potential of FAPI PET imaging in breast cancer; however, this case highlights that false-negative 68 Ga-FAPI-04-PET/CT findings should also be considered while evaluating metastatic spread., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: 68 Ga-fibroblast activation protein inhibitor (FAPI) PET/CT is an emerging imaging modality with high sensitivity and high tumor-to-background ratio in various cancers including in the head and neck regions. The authors present 2 cases of adenoid cystic carcinoma who underwent 68 Ga-FAPI-04 and 18 F-FDG PET/CT. Locoregional recurrence has been detected more precisely in the first case with 68 Ga-FAPI-04. In the second case, 68 Ga-FAPI-04 outperformed 18 F-FDG in the number of lesions and demonstrated intense FAP uptake on widespread metastases, which could provide a treatment option as a theranostic concept. These cases highlight that 68 Ga-FAPI-04 PET/CT may be useful for detecting local recurrence and metastases and help select patients for radionuclide treatments targeting cancer-associated fibroblasts., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We present the 68 Ga-DOTATATE and 68 Ga-FAPI (fibroblast activation protein inhibitor) PET/CT findings of a 61-year-old man diagnosed with atypical World Health Organization grade II multiple meningiomas. The patient has been stable for 2 years following multiple surgeries and external radiotherapy because of recurring disease until he recently described frequent headaches, and a follow-up examination confirmed new meningioma lesions on MRI. However, the patient was inoperable and was referred for 68 Ga-DOTATATE PET/CT to determine eligibility for salvage peptide receptor radionuclide therapy. He also underwent fibroblast activation protein-targeted imaging using 68 Ga-FAPI04 PET/CT, which revealed heterogeneous, low to mild fibroblast activation protein expression across multiple meningioma lesions., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Papillary renal cell cancer is a rare malignancy with limited treatment options in the advanced stage of the disease. We present the case of a 62-year-old man with progressive left-sided papillary renal cell carcinoma who underwent 68 Ga-FAPI (fibroblast activated protein inhibitor)-04 and 18 F-FDG PET/CT imaging. 68 Ga-FAPI-04 PET/CT demonstrated variable FAP expression in all metastatic lesions detected by 18 F-FDG PET/CT, including multiple lymph nodes, bone, and thyroid. This case highlights that FAP-targeted imaging can be a promising modality for diagnostic and theranostic use in papillary renal cell carcinoma., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: We assessed the feasibility of SPECT/CT lymphoscintigraphy ( 99m Tc-nanocolloid) method to simplify and improve targeted axillary dissection of clipped axillary lymph node (axLN) after neoadjuvant chemotherapy (NAC) in initially node-positive breast cancer., Patients and Methods: Fifteen patients who had clip placement to biopsy-confirmed axLN metastasis due to clinically node-positive breast cancer before NAC and underwent SPECT/CT lymphoscintigraphy for surgery after NAC were included into the study. SPECT/CT lymphoscintigraphy was performed to localize the clipped node and to assess if the clipped lymph node (LN) had 99m Tc-nanocolloid uptake or not. In case the clipped node had no uptake on SPECT/CT, the patient was referred to wire-guided localization procedure. Blue dye was also injected for dual mapping of sentinel LN biopsy., Results: All patients had only ipsilateral axLN metastasis. SPECT/CT lymphoscintigraphy showed that clipped LNs were radioavid in 12 of 15 patients (80%). Clipped LNs were not blue-stained in 5 patients (33.3%), and in 2 of them, clipped LNs were radioavid in SPECT/CT. Wire-guided localization was required in only 3 patients (20%) for nonradioavid/blue-stained clipped LNs. Removal of the clipped nodes was confirmed in all cases with a success rate of 100% by specimen graphy., Conclusion: SPECT/CT lymphoscintigraphy seems feasible to determine the clipped LNs intraoperatively without requiring additional invasive methods in most of the patients. This technique simplifies and improves targeted axillary dissection of the clipped axLNs after NAC in initially node-positive breast cancer and can be adapted to clinical practice with further investigations., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: This study was set out to analyze the efficacy and safety of 177 Lu-PSMA-617 (LuPSMA) treatment in metastatic castration-resistant prostate cancer (mCRPC) patients., Patients and Methods: Progressive mCRPC patients who received at least 1 cycle of LuPSMA therapy were evaluated retrospectively. Demographic, clinic, and histopathological data were documented. Treatment efficacy was determined based on biochemical response criteria (Prostate Cancer Clinical Trial Working Group 3), and toxicity rates were defined based on CTCAE v4.03. The prognostic significance of laboratory/clinical data and 68 Ga-PSMA PET/CT quantitative results were analyzed using SPSS Version 24.0., Results: One hundred patients (median prostate-specific antigen [PSA] level, 75.7 ng/mL) who met the eligibility criteria were identified. The median number of cycles received per patient was 3 (range, 1-9). After the first cycles of LuPSMA, biochemical partial response, biochemical stable disease, and biochemical progressive disease were observed in 31%, 36%, and 33% of patients, respectively. Any PSA decline was determined in 60% of patients. After the fourth cycle of treatment, biochemical partial response, biochemical stable disease, and biochemical progressive disease were defined in 48%, 26%, and 26% of patients, respectively. The median overall survival (OS) from the first cycle of LuPSMA was 14 months. Patients who had any PSA response after the first cycle had significantly longer OS than nonresponders (median OS: 17 vs 9 months; P ≤ 0.001). Total PSMA-derived tumor volume ( P = 0.004), total PSMA activity per lesion ( P = 0.01), PSA ( P = 0.007), alkaline phosphatase ( P = 0.002), lactate dehydrogenase ( P < 0.001), and hemoglobin ( P < 0.001) were significant prognostic factors for OS in univariate Cox regression analysis., Conclusions: LuPSMA therapy is a favorable treatment for mCRPC with remarkable therapeutic efficacy and low toxicity rates, even in progressive disease under standard therapies. Baseline PSMA-based tumor burden, PSA, alkaline phosphatase, lactate dehydrogenase, and hemoglobin were significant predictors of OS and can be useful for selection of the best candidate for LuPSMA therapy., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Herein we present 2 mCRPC (metastatic castration-resistant prostate cancer) patients who underwent 68Ga-PSMA PET/CT for PSMA-targeted radioligand therapy eligibility. Prior studies have noted aggressive clinical behavior and poor prognosis associated with discordant FDG positivity and low PSMA expression. Accordingly, the patients also underwent 18F-FDG PET/CT, which revealed intratumoral heterogeneity. Therefore, an additional PET/CT targeting fibroblast activation proteins (FAPs) using 68Ga-FAPI-04 was performed to assess the potential for an FAP-targeted therapy. This report highlights the theranostic potential of FAP imaging in mCRPC, particularly in patients with heterogeneous tumor phenotypes., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Herein, we present a 72-year-old woman with metastatic thymic carcinoma, referred for salvage peptide receptor radionuclide therapy with 177Lu-DOTATATE after completing all treatment options according to current clinical practice and guidelines. However, the patient was not eligible for 177Lu-DOTATATE peptide receptor radionuclide therapy and underwent 68Ga-FAPI04 PET/CT to assess the potential for a FAP-targeted therapy., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Prostate-specific membrane antigen (PSMA)-targeted therapies are among the current promising treatments. We present our preliminary results on the use of 225Ac-PSMA therapy in patients with metastatic castration-resistant prostate cancer as a single center., Methods: Twelve advanced stage metastatic castration-resistant prostate cancer patients who received 225Ac-PSMA therapy were recruited in this retrospective study. Patients were treated with 225Ac-PSMA therapy every 8 weeks, and prostate-specific antigen (PSA) response was analyzed. Meanwhile, overall survival (OS) and progression-free survival (PFS) were estimated. Hematological and nonhematological adverse effects were recorded before and at 8 weeks after the last treatment cycle., Results: In total, 25 cycles of 225Ac-PSMA were administered to 12 patients. The pretreatment median PSA level was 129 ng/mL. After the first cycle of therapy, any PSA response was observed in 9 of 12 patients, whereas 6 of them had biochemical response of >50%. Four of 12 patients reached the best PSA response after the first treatment cycle, whereas 3 patients after the second and 2 patients after the third cycle. The median PFS and OS were 4 and 10 months, respectively. For patients with any PSA response after the first cycle, OS was found to be higher despite without any statistical significance (10 vs 4 months; P = 0.301) when compared with the nonresponsive group. No significant difference was encountered in terms of adverse effect in the pretreatment and posttreatment era., Conclusions: Our preliminary results are encouraging, especially patients who had PSA response after the first cycle of 225Ac-PSMA therapy., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: This study is set out to estimate the radiation-absorbed doses to normal organs and tumor tissue using low-dose 177Lu-FAPI04 dosimetry to determine the safety and theranostic potential of fibroblast activation protein-targeted radionuclide therapy., Patients and Methods: Four patients with metastatic advanced-stage cancer were administered low-dose 177Lu-FAPI04 for dosimetry measurements. Data acquisition for dosimetry of normal organs and tumors was performed by whole-body and 3D SPECT/CT imaging at 4, 24, 48, and 96 hours after administering 177Lu-FAPI04. Blood samples were drawn at 5, 15, 30, 60, 60, 120, and 180 minutes, and at 24, 48, and 96 hours for bone marrow dosimetry calculations., Results: Mean absorbed doses per megabecquerel were 0.25 ± 0.16 mGy (range, 0.11-0.47 mGy), 0.11 ± 0.08 mGy (range, 0.06-0.22 mGy), and 0.04 ± 0.002 mGy (range, 0.04-0.046 mGy) for kidneys, liver, and bone marrow, respectively. The respective maximum estimated amount of radioactivity to reach radiation-absorbed dose limits were 120.9 ± 68.6 GBq, 47.5 ± 2.8 GBq, 397.8 ± 217.1 GBq, and 52.4 ± 15.3 GBq for kidneys, bone marrow, liver, and total body. The mean absorbed dose per megabecquerel was 0.62 ± 0.55 mGy for bone metastases, 0.38 ± 0.22 mGy for metastatic lymph nodes, 0.33 ± 0.21 mGy for liver metastases, and 0.37 ± 0.29 for metastatic soft tissue. The maximum absorbed dose in a tumor lesion was 1.67 mGy/MBq for bone, 0.6 mGy/MBq for lymph node, 0.62 mGy/MBq for liver, and 1 mGy/MBq for soft tissue., Conclusions: The mean absorbed dose to organs at risk with 177Lu-FAPI04 is reasonably low, allowing for low tumor-absorbed dose rates by administering a higher dose. Further research on optimizing therapeutic efficacy and using alternative radioisotopes is necessary, along with an individualized dosimetric approach., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Somatostatin receptor (SSTR) imaging with 68Ga-labeled somatostatin analogs has been used for many tumors with high SSTR expression. Increased uptake mostly depends on the SSTR status of tumors; however, false-positive uptake can be demonstrated in benign diseases or other malignancies because of the increased SSTR expression. We present a case of a 50-year-old man with increased SSTR activity on cervical lesion located in internal jugular chain in 68Ga-DOTATATE PET/CT, which was performed for suspicion of paraganglioma. Biopsy revealed lymph node metastasis of squamous cell carcinoma other than paraganglioma. 18F-FDG PET/CT showed primary malignancy on larynx and lymph node metastasis, which were correlated surgically., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We present a case of a 55-year-old man with a history of poorly differentiated metastatic thyroid cancer, which is rare and shows aggressive behavior. The patient had radioactive iodine-negative multiple metastasis on 18F-FDG PET/CT, therefore 68Ga-DOTATATE and 68Ga-PSMA PET/CT were performed whether an opportunity exist for DOTATATE or PSMA-directed radionuclide therapy. Different patterns of tumoral uptakes were detected on 18F-FDG, 68Ga-DOTATATE, and 68Ga-PSMA PET/CT, as a demonstration of tumor heterogeneity., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)