Objective: To evaluate the feasibility of streamlined radioembolization using yttrium-90 resin microspheres without lung shunt fraction (LSF) assessment in patients with intrahepatic cholangiocarcinoma (ICC). Materials and Methods: This single-center retrospective study included 23 patients with ICC who underwent radioembolization using resin microspheres (SIR-Spheres; SIRTEX, Woburn, MA, USA) without LSF measurement between April 2022 and April 2025.Eligibility criteria, based on prior institutional data, included a target tumor size less than 10 cm, absence of hepatic vein invasion and intratumoral dysmorphic vessels, and an institutional waiting time exceeding one week for macroaggregated albumin scintigraphy. All patients had at least one follow-up imaging study. Radiation activity was prescribed according to tumor location, liver function, and clinical setting, using both single-compartment and multi-compartment dosimetry under the assumptions of a 5% LSF and a tumor-to-normal (TN) ratio of 3. Post-treatment yttrium-90 PET/CT dosimetry was performed in 12 patients. Treatment-related toxicity, tumor response, and local tumor progression-free survival were analyzed. Results: The median administered activity was 1.43 GBq (interquartile range, 0.89–2.15). The median mean absorbed dose to the perfused tissue was 147 Gy, and the median tumor absorbed dose (TAD) was 339 Gy, assuming a TN ratio of 3. Posttreatment PET/CT analysis demonstrated a median TAD of 371 Gy and a median TN ratio of 4.7. No patient developed symptomatic radiation pneumonitis. Best tumor response was partial response in 52% of patients and stable disease in 48%. Local tumor progression-free survival rates at six months, one year, and two years were 95.2%, 81.1%, and 81.1%, respectively. Conclusion Streamlined radioembolization without LSF assessment appears feasible and may represent a practical alternative to conventional multi-step workflows in patients with ICC measuring less than 10 cm.

Purpose: Radiotherapy is used to reduce the risk of breast cancer recurrence after surgery, but it is a potential cause of secondary cancer. We validated the risk of secondary cancer in primary breast cancer who received radiotherapy compared with those who did not from a matched cohort using a large-scale observational study of the Observational Health Data Sciences and Informatics (OHDSI) data network. Materials and Methods: A retrospective comparative cohort study using propensity score-matched cohorts was performed using two Observational Medical Outcome Partnership common data model databases, from tertiary general hospitals in South Korea. Among female patients who underwent surgery after the diagnosis of breast cancer, the risk of secondary primary malignant occurrence after 1:1 matching was analyzed. Results: Among 27,078 patients with breast cancer, there was no significant difference in the risk of secondary cancer following radiotherapy in 4,426 patients after 1:1 propensity-score matching. Further, there were no significant differences in the sensitivity analysis according to age, latency period, and number of radiation treatments. Conclusion There was no difference in the risk of secondary cancer in the patients diagnosed with breast cancer depending on whether or not radiotherapy was performed after surgery. In the future, it is necessary to analyze including data generated during cancer treatment.

Objective: This study compared clinical and cosmetic outcomes of cranioplasty using customized three-dimensional (3-D) printed implants versus autologous bone in patients with aneurysmal subarachnoid hemorrhage (aSAH) after decompressive craniectomy (DC). Methods: We retrospectively reviewed 50 patients who underwent cranioplasty after DC for aSAH between July 2018 and December 2023. Patients were divided into the three-dimensional cranioplasty(3-DC, n=26) and autologous bone cranioplasty (AC, n=24) groups. Demographics, aneurysm characteristics, surgical parameters, morphometric analysis of defect coverage, complications, and functional outcomes assessed by the modified Rankin Scale (mRS) were compared. Results: A total of 54 hemispheres underwent cranioplasty. Compared with AC, the 3-DC group had larger defects but achieved higher coverage (96.7% vs. 93.4%, p=0.044) and smaller residual defects (338.7±274.2 mm² vs. 528.5±331.3 mm², p=0.049). Complication rates were lower in 3-DC (9 cases) than AC (15 cases, p=0.0994). Wound dehiscence and fluid collection were more frequent with 3-DC, while bone flap resorption and epidural abscess occurred only with AC. Revision surgery was required in six patients, five initially treated with autologous bone. Neurological outcomes (mRS) were maintained or improved in both groups. Conclusions In aSAH patients undergoing cranioplasty after DC, customized 3-D printed implants achieved significantly better anatomical restoration and showed a numerical trend toward fewer complications compared with autologous bone. While AC remains feasible, its risks of resorption and infection often necessitate revision. 3-D printed implants may be considered a reasonable alternative, particularly in aSAH patients at higher risk of complications.

Solid pseudopapillary tumor (SPT) of the pancreas is a neoplasm with low malignant potential. It is often challenging to diagnose SPT due to its nonspecific clinical and radiological features, and ­[18F]FDOPA is effective in diagnosing SPT, particularly in differentiating SPT from benign conditions such as splenosis. A 55-year-old woman underwent distal pancreatectomy and splenectomy for histologically confirmed SPT. She was also initially diagnosed with splenosis. During follow-up, sizes of multiple nodular lesions were increased, raising the possibility of peritoneal seeding of SPT. For diagnosis, a spleen scan and SPECT/CT were performed using 99mTc-labeled damaged red blood cells, which showed no uptake in the peritoneal nodules. Subsequent ­[18F]FDOPA PET/CT revealed ­[18F]FDOPA-avidity of the nodules. The patient underwent tumor resection surgery, and the nodules were pathologically confirmed as SPT.

Background and Objectives: Recent guidelines from the Korean Thyroid Association have proposed a threshold of 6.8 mIU/L for diagnosing subclinical hypothyroidism based on local research findings. However, due to the lack of standardization/harmonization, thyroid-stimulating hormone (TSH) testing yields varying results across different reagent manufacturers. Hence, the use of uniform reference intervals is challenging. We aimed to establish assay-specific Korean reference interval for TSH. Materials and Methods: We performed duplicate measurements on 100 serum samples with varying TSH concentrations (0-23 mIU/L) using eight different TSH reagents including Alinity I TSH (Abbott), Access TSH (Beckman Coulter), Elecsys TSH (Roche), TSH3UL (Siemens),TSH IRMA (Beckman Coulter), TSH1 RIA (Brahms), TSH IRMA TUBE II (Riakey), Turbo TSH IRMA (Izotop).Correlation and simple linear regression analyses were conducted among 8 reagents with Roche as the reference. Results The correlation coefficient for each reagent was notably high at 0.99. Through regression analysis, TSH values equivalent to the 6.8 mIU/L (Roche) were determined for each reagent as follows: Abbott 5.2 mIU/L, Beckman 6.5 mIU/L, Siemens 6.9 mIU/L, Beckman-Radioimmunoassay 7.4 mIU/L, Brahms 5.7 mIU/L, Riakey 5.3 mIU/L, Izotop 6.0 mIU/L. Conclusion: Given the observed differences in TSH values associated with different reagents, it is imperative to consider these differences when interpreting results within various clinical contexts and adapting them to clinical practice.

Pheochromocytoma and paraganglioma (PPGLs) are rare catecholamine-secreting neuroendocrine tumors but can be life-threatening. Although most PPGLs are benign, approximately 10% have metastatic potential. Approximately 40% cases are reported as harboring germline mutations. Therefore, timely and accurate diagnosis of PPGLs is crucial. For more than 130 years, clinical, molecular, biochemical, radiological, and pathological investigations have been rapidly advanced in the field of PPGLs. However, performing diagnostic studies to localize lesions and detect metastatic potential can be still challenging and complicated. Furthermore, great progress on genetics has shifted the paradigm of genetic testing of PPGLs. The Korean PPGL task force team consisting of the Korean Endocrine Society, the Korean Surgical Society, the Korean Society of Nuclear Medicine, the Korean Society of Pathologists, and the Korean Society of Laboratory Medicine has developed this position statement focusing on the comprehensive and updated diagnosis for PPGLs.

Background and Objectives: Quantitative flow ratio (QFR) is an angiography-based technique for functional assessment of coronary artery stenosis. This study investigated the response of QFR to different degree of stenosis severity and its ability to predict the positron emission tomography (PET)-defined myocardial ischemia. Methods: From 109 patients with 185 vessels who underwent both 13 N-ammonia PET and invasive physiological measurement, we compared QFR, fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) for the responses to the different degree of anatomical (percent diameter stenosis [%DS]) and hemodynamic (relative flow reserve [RFR], coronary flow reserve, hyperemic stenosis resistance, and stress myocardial flow) stenosis severity and diagnostic performance against PET-derived parameters. Results: QFR, FFR, and iFR showed similar responses to both anatomic and hemodynamic stenosis severity. Regarding RFR, the diagnostic accuracy of QFR was lower than FFR (76.2% vs. 83.2%, p=0.021) and iFR (76.2% vs. 84.3%, p=0.031). For coronary flow capacity (CFC), QFR showed a lower accuracy than iFR (74.1% vs. 82%, p=0.031) and lower discriminant function than FFR (area under curve: 0.74 vs. 0.79, p=0.044). Discordance between QFR and FFR or iFR was shown in 14.6% of cases and was driven by the difference in %DS and heterogeneous distribution of PET-derived RFR and stress myocardial blood flow. Conclusions QFR demonstrated a similar response to different anatomic and hemodynamic stenosis severity as FFR or iFR. However, its diagnostic performance was inferior to FFR and iFR when PET-derived RFR and CFC were used as a reference.