Hydraulic recharge and element dynamics during salinization in an overexploited coastal aquifer of the world's driest zone: Atacama Desert.

The management of water resources in hyper-arid coastal regions is a challenging task because proper information regarding groundwater recharge and water budget is needed for maintaining the hydraulic balance in optimal conditions, avoiding salinization and seawater intrusion. Thus, this article deals with the estimation of the hydraulic recharge and the study of the effects of salinization on the dynamics of major and trace elements in an alluvial aquifer located in the world's driest zone, the northern Atacama Desert. The result of stable water isotopes (δD and δ18O) and tritium (3H) indicated that groundwater in the area is not recent, whereas 14C results estimated a groundwater residence time ranging between 11,628 and 16,067 yBP. The estimation of the artificial recharge coming from the urban water-supply-system leaks and wastewater/river-water/groundwater infiltration during irrigation was about 19.84 hm3/year, which represents an annual negative water balance of 177 hm3/year for the aquifer. The groundwater salinization triggered by seawater intrusion (up to 32.6 %) has caused the enrichment of Li, Rb, Ca, Ba, and Sr in groundwater by cationic exchange, where the excess of aqueous Na is exchanged by these elements in the aquifer sediments. Other elements such as B, Se, Si, and Sb are enriched in groundwater by ionic strength and/or anionic exchange during salinization. The heightened B concentrations derived from the B-rich alluvial sediments were higher than the limit suggested by international guidelines, representing a risk to consumers. Vanadium seems to be unaffected by salinization, whereas Pb, Mo, As, U, and Zr did not show a clear behavior during saline intrusion. Finally, this article highlights the consequences of conducting improper water management in coastal hyper-arid regions with exacerbated agriculture.

Predictive factors for treatment response in active thyroid eye disease.

INTRODUCTION/OBJECTIVE: Active moderate-to-severe thyroid eye disease (TED) is a major therapeutic challenge. Pulse therapy with intravenous glucocorticoids is the standard treatment, with variable response. Radioactive iodine therapy (RAI) was reported as a risk factor for onset or worsening of TED. We evaluated putative predictive factors for response to intravenous methylprednisolone in patients with active TED. METHODS: Data were collected for 64 consecutive patients (45 women) with active moderate-to-severe TED treated with a minimum cumulative dose of 4.5g methylprednisolone. Patients were classified as responders (R) or non-responders (NR) on Clinical Activity Score (CAS), and clinical features were compared between groups. RESULTS: Sixty-two patients had Graves' disease (GD), and 2 had Hashimoto's thyroiditis (HT). Median age at thyroid dysfunction diagnosis, TED manifestation and pulse therapy was 46, 48 and 51 years, respectively; 56.2% were euthyroid when TED manifested. Among them, 73.4% were responders. R and NR were comparable for gender, age, thyroid function, serum antibodies, disease duration, pre-treatment CAS, smoking, lipid profile, and adverse events. Forty-nine patients were treated with RAI for GD: 15 before the active phase of TED (before pulse therapy), 16 during, 17 after, and 1 both before and after pulse therapy. Response rate was higher in patients who received RAI during than after pulse therapy (P=0.032) and similar to those not treated with RAI at all (P=0,599). CONCLUSION: Pulse therapy was effective in the majority of patients. The only factor associated with response to pulse therapy was the timing of RAI, suggesting that it seems to be safe when used concomitantly with pulse therapy.

Multimodal image-guided surgical robot versus 3D-printed template for brachytherapy of malignant tumours in the skull base and deep facial region: a clinical comparative study.

This study compared a multimodal image-guided robot and three-dimensionally (3D) printed templates for implanting iodine-125 (I125) radioactive seeds in patients with malignant tumours in the skull base and deep facial region. Seventeen patients who underwent I125 radioactive seed implantation between December 2018 and December 2019 were included. The operation time, intraoperative blood loss, and accuracy of seed implantation were compared between the multimodal image-guided robot-assisted implantation (experimental) group (n = 7) and 3D-printed template-assisted implantation (control) group (n = 10). In total, 291 seeds were implanted in the experimental group and 436 in the control group; the mean error of seed implantation accuracy was 1.95 ± 0.13 mm and 1.90 ± 0.08 mm, respectively (P = 0.309). The preparation time was 26.13 ± 5.28 min in the experimental group and 0 min in the control group, while the average operation time was 34.44 ± 6.39 min versus 43.70 ± 6.06 min, respectively. The intraoperative blood loss was 4.96 ± 1.76 ml (experimental) versus 8.97 ± 2.99 ml (control) (P = 0.123). Multimodal image-guided robot-assisted I125 radioactive seed implantation met the clinical requirements for treating malignant tumours in the skull base and deep facial regions.

Nanoscale dosimetry for a radioisotope-labeled metal nanoparticle using MCNP6.2 and Geant4.

BACKGROUND: Metal nanoparticles (MNPs) labeled with radioisotopes (RIs) are utilized as radio-enhancers due to their ability to amplify the radiation dose in their immediate vicinity. A thorough understanding of nanoscale dosimetry around MNPs enables their effective application in radiotherapy. However, nanoscale dosimetry around MNPs still requires further investigation. PURPOSE: This study aims to provide insight into the radio-enhancement effects of MNPs by elucidating nanoscale dosimetry surrounding MNPs labeled with Auger-emitting RIs. We particularly focus on distinguishing the respective dose contributions of photons and electrons emitted by Auger-emitting RIs in the context of dose enhancement. METHODS: A 50 nm diameter NP of silver (Ag) core and gold (Au) shell (Ag@Au NP) was assumed to emit mono-energetic electrons and photons (3, 5, 10, 20, and 30 keV), or the energy spectrum corresponding to one of three Auger-emitting RIs (103Pd, 125I, and 131Cs) from the Ag core. Nanoscale radial dose distributions around a single radioactive Ag@Au NP were evaluated in spherical shells of water. Monte Carlo simulations were conducted using single-event and track structure transport methods implemented in MCNP6.2 and Geant4-DNA-Au physics, respectively. To evaluate the extent of radio-enhancement by the Ag@Au NP, two scenarios were considered: Ag@Au NPs (Au shell included) and Ag@water NPs (Au shell replaced by water). RESULTS: The radial doses of 10, 20, and 30 keV electrons estimated by both codes were comparable. However, the radial doses of 3 and 5 keV electrons by MCNP6.2 were much larger near the NP surface than those by Geant4. There was a dose enhancement of a few % to tens % by the Au shell in the region of the NP surface to 10 µm, depending on the electron energy. The radial doses of photons with the Au shell were higher up to their secondary electron ranges than those without the Au shell. The maximum dose enhancement factor of photons occurred at 20 keV and was 63.4 by MCNP6.2 and 50.5 by Geant4. The overall radial doses of electrons were 1-2 orders of magnitude larger than those of photons. As a result, in cases of RIs emitting both electrons and photons, the radial doses up to electron ranges were dominantly governed by electrons. The dose enhancement estimated by both codes for the RIs ranged from a few % except in the immediate vicinity of the NP surface. CONCLUSION: Given the dominant contribution of electrons to radial doses of MNP labeled with Auger-emitting RIs, physical dose enhancement expected by interactions with photons was hindered. Since there are no available RIs emitting exclusively photons, achieving enhanced physical doses within a cell through a combination of MNPs and RIs appears currently unattainable. The radial doses of photons near the NP surface exhibited considerable discrepancies between the codes, primarily attributed to low-energy electrons. The difference may arise from higher cross-sections of Au inelastic scattering in Geant4-DNA-Au compared to MCNP6.2.

Serum Potassium in Thyroid Cancer Patients With Hypothyroidism During Thyroid Hormone Withdrawal: A Retrospective Study.

Background: Several case reports and a few studies have reported that hypothyroid patients have elevated serum potassium levels. However, hypothyroidism has not been widely accepted as a cause of hyperkalemia. Objectives: This study aims to evaluate the incidence of hyperkalemia and factors influencing serum potassium levels in thyroid cancer patients with hypothyroidism during thyroid hormone withdrawal before radioactive iodine (RAI) treatment. Methods: We conducted a retrospective review of electronic medical records from January 2017 to June 2021, involving 956 thyroid cancer patients post-thyroidectomy and undergoing RAI. Laboratory parameters, including serum potassium levels, were collected in both euthyroid (<1 year prior to RAI) and hypothyroid states. Results: Among 508 patients (mean age 52 years, 79.3% female), hyperkalemia (potassium ⩾ 5.0 mEq/L) occurred in 2.8%, without severe hyperkalemia (potassium ⩾ 6.5 mEq/L). The hypothyroid state exhibited significantly higher serum potassium than the euthyroid state [4.16 (IQR, 3.94-4.41) vs 4.10 (IQR, 3.90-4.35) mEq/L, P < .01]. The mean change in potassium levels between the euthyroid and hypothyroid state was 0.05 ± 0.17 mEq/L. Pre-thyroid hormone withdrawal (euthyroid state) factors associated with serum potassium levels in the hypothyroid state included age, use of angiotensin-converting enzyme inhibitors, diabetes mellitus, serum BUN/creatinine, serum potassium levels, hemoglobin A1c (positive correlation); and thiazide use and eGFR (negative correlation). In the hypothyroid state, hyperkalemia was more likely in patients with serum potassium ⩾4.2 mEq/L (OR 9.36, P < .01) or free T4 ⩾1.38 ng/dL (OR 7.05, P < .01) during the euthyroid state. Conclusions: The incidence of hyperkalemia was low in our hypothyroid cohorts. However, physicians should remain vigilant for cases with risk factors for developing hyperkalemia.

Serum Potassium in Hypothyroid Patients A retrospective cohort study of thyroid cancer patients undergoing radioactive iodine therapy found a low incidence of hyperkalemia (2.8%) during hypothyroidism. Patients exhibited higher serum potassium levels, influenced by factors included age, medication use (ACEI), diabetes mellitus, and initial potassium levels. Elevated initial potassium and thyroid hormone levels were associated with higher risk of hypothyroid-related hyperkalemia. Physicians should remain vigilant for hyperkalemia in these patients, particularly those with predisposing factors, warranting further mechanistic studies and broader validations.

Design and thermal-hydraulic analysis of multi-target system with 100 MeV proton linear accelerator for the production of 67Cu and 68Ge radioisotopes.

Radioisotopes are widely used in the fields of medicine, science, and industry. The growing demand for medical radioisotopes has driven research on alternative production methods. In particular, both isotopes of 67Cu and 68Ge play vital roles in the medical environment in many countries to be used in the radio-immunotherapy and the positron emission tomography imaging, respectively. This study designed a multi-target system consisting of two Zn and one Ga2O3 plates to enable simultaneous production of the medical radioisotopes 67Cu and 68Ge using 100 MeV proton beams. To understand the thermal effect on the multi-targets, we examined the distribution of energy absorbed in each solid plate target when exposed to an accelerated proton beam through the thermal-fluid analysis based on ANSYS simulation. For confirming thermal stability for two Zn targets and one Ga2O3 target, the modified water flow path inside the multi-target system was designed effectively with the controlled distribution of multiple sub-holes between main inlet and the following four channels. It was confirmed that the newly designed multi-target system of Zn and Ga2O3 solid plates shows higher thermal stability than the case of uniform distribution of water inlet, which means it could be exposed to a higher current beam of 7.57% to decrease the processing time.

A retrospective study of 68Ga-FAPI PET/CT in differentiating the nature of pulmonary lesions.

Purpose: This study aimed to investigate the characteristics of various pulmonary lesions as revealed by 68Ga-FAPI PET/CT and to determine the utility of 68Ga-FAPI PET/CT in distinguishing the nature of these pulmonary lesions. Methods: A retrospective analysis was conducted on 99 patients with pulmonary lesions, who were categorized into three distinct groups: primary lung tumors (G1), metastatic lung tumors (G2), and benign lesions (G3). Each participant underwent a 68Ga-FAPI PET/CT scan. Among these groups, variables such as the Tumor/Background Ratio (TBR), Maximum Standardized Uptake Value (SUVmax), and the true positive rate of the lesions were compared. Furthermore, the FAPI uptake in nodular-like pulmonary lesions (d<3cm) and those with irregular borders was evaluated across the groups. A correlation analysis sought to understand the relationship between FAPI uptake in primary and pulmonary metastatic lesions. Results: The study's participants were composed of 52 males and 47 females, with an average age of 56.8 ± 13.2 years. A higher uptake and detection rate for pulmonary lesions were exhibited by Group G1 compared to the other groups (SUVmax [G1 vs. G2 vs. G3: 9.1 ± 4.1 vs. 6.1 ± 4.1 vs. 5.3 ± 5.8], P<0.05; TBR [G1 vs. G2 vs. G3: 6.2 ± 2.4 vs. 4.1 ± 2.2 vs. 3.2 ± 2.7], P<0.01; true positive rate 95.1% vs. 88% vs. 75.6%]. In nodular-like lung lesions smaller than 3 cm, G1 showed a significantly higher FAPI uptake compared to G2 and G3 (SUVmax [G1 vs. G2 vs. G3: 8.8 ± 4.3 vs. 5.2 ± 3.2 vs. 4.9 ± 6.1], P<0.01; TBR [G1 vs. G2 vs. G3: 5.7 ± 2.7 vs. 3.7 ± 2.1 vs. 3.3 ± 4.4], P<0.05). Both G1 and G2 demonstrated significantly elevated FAPI agent activity in irregular-bordered pulmonary lesions when compared to G3 (SUVmax [G1 vs. G2 vs. G3: 10.9 ± 3.3 vs. 8.5 ± 2.7 vs. 4.6 ± 2.7], P<0.01; TBR [G1 vs. G2 vs. G3: 7.2 ± 2.1 vs. 6.4 ± 1.3 vs. 3.2 ± 2.4], P<0.01). A positive correlation was identified between the level of 68Ga-FAPI uptake in primary lesions and the uptake in pulmonary metastatic lesions within G2 (r=0.856, P<0.05). Conclusion: 68Ga-FAPI PET/CT imaging proves to be of significant value in the evaluation of pulmonary lesions, offering distinctive insights into their nature.

Salivary, lacrimal and nasal (SALANS) measure to assess side effects following radioactive iodine treatment: development, psychometric properties, and factor structure.

PURPOSE: This study aimed to develop and psychometrically evaluate a patient-reported outcome measure (PROM), SAlivary, LAcrimal, NaSal (SALANS), to document patients' symptoms after radioactive iodine (RAI) treatment for differentiated thyroid cancer (DTC). METHODS: We generated and iteratively revised SALANS items based on expert input, focus group discussions and feedback from cognitive testing (n = 17). We administered an initial SALANS measure with 39 items to patients diagnosed with DTC in the past two years (n = 105). Exploratory factor analysis (EFA) examined the factor structure of the SALANS items. We assessed the consistency reliability and related the total and subscale scores of the final SALANS to existing PROMs to assess validity. RESULTS: The final SALANS consisted of 33 items and six subscales (sialadenitis, taste, xerostomia, dry eyes, epiphora, and nasal) with six factors extracted by EFA. The six subscales demonstrated good internal reliability (α range = 0.87-0.92). The SALANS total score showed good convergent validity with the Xerostomia Inventory (r = 0.86) and good discriminant validity with a measure of spirituality (r = - 0.05). The mean SALANS total score was significantly higher (d = 0.5, p < 0.04) among patients who had RAI compared to those who did not have RAI. CONCLUSION: Preliminary evidence suggests that SALANS is a novel and reliable PROM to assess the type and frequency all symptoms experienced after RAI treatment for DTC. Future work is needed to further validate and develop the scale.

The clinical value of iodine-125 seed implantation in the treatment of iodine-refractory differentiated thyroid carcinoma.

Objective: To explore the clinical benefits of 125I seed implantation for iodine-refractory differentiated thyroid cancer (RAIR-DTC). Methods: A retrospective analysis was conducted on 36 patients with RAIR-DTC who underwent radioactive 125I seed implantation from January 2015 to February 2022, involving 73 lesions. Prescription dose: 80~120 Gy. All cases were followed up at 1, 3, and 5 months postoperatively to monitor changes in tumor size, serum thyroglobulin (Tg), and serum anti-thyroglobulin antibody levels in thyrotropin-inhibited states, pain scores, and postoperative adverse reactions. The data were processed and analyzed using IBM SPSS 26.0. LER (Local Effective Rate) and LCR (Local Control Rate) were expressed as n (%), tumor diameter, Tg, and pain scores were represented as Median (Q1, Q3). Pairwise comparisons were conducted using the Wilcoxon signed-rank test, and a p-value of less than 0.05 indicated statistical significance. Results: Tumor size was significantly reduced after treatment (all P < 0.001): tumor length diameters were 32.67 (17.70, 45.72) mm, 27.45 (12.30, 39.98) mm, 20.70 (11.98, 37.58) mm, and 20.39 (10.56, 33.20) mm in the preoperative, 1-, 3-, and 5-months postoperative periods, respectively. Additionally, two consecutive post-treatment results were more minor and statistically significant than the previous results (P < 0.001). The LER at 1-, 3-, and 5-months post-surgery was 23.73%, 38.98%, and 52.54%, respectively, while the LCR at the same time points was 98.31%, 96.61%, and 94.92%, respectively. Patients' serum Tg levels decreased significantly after surgery. (P < 0.001). Serum Tg levels were measured before surgery and 1-, 3-, and 5-months post-surgery. The results showed that serum Tg levels were 249.45 (79.39, 4718.75) ng/ml, 193.40 (44.53, 2829.00) ng/ml, 192.10 (25.58, 1758.00) ng/ml, and 136.25 (16.57, 1553.25) ng/ml, respectively. Two consecutive post-treatment results were more minor and statistically significant than the previous results (P < 0.001). The patients' pain symptoms were significantly relieved after 125I brachytherapy (P < 0.001). The pain scores before 125I seed implantation and at 1, 3, and 5 months after the operation were 5.00 (4.00, 6.00), 3.00 (2.25, 4.00), 2.00 (2.00, 3.00), and 2.00 (1.00, 3.00), respectively. Conclusion: Most lesions treated with 125I seed implantation in RAIR-DTC patients showed shrinkage and improved pain symptoms. Clinical trial registration: https://www.clinicaltrials.gov, identifier NCT06362772.

Do You Know What You Drink? Comparative Research on the Contents of Radioisotopes and Heavy Metals in Different Types of Tea from Various Parts of the World.

The aim of this study was to assess the potential health risks of radioactive elements and heavy metals ingested through the consumption of various types of tea imported to the Polish market (black, green, red, oolong and white). The concentrations [Bq/kg] of radionuclides (40K, 137Cs, 226Ra, 210Pb and 228Th) in tea leaves before and after brewing were measured using γ-ray spectrometry with high-purity germanium (HPGe). The concentrations [mg/kg] of the studied elements (Fe, Cr, Cu, Mo, Al, Mn, Ni, P, V, Cd and Pb) were determined using a microwave-induced plasma optical emission spectrometer (MIP-OES). The results presented here will help to expand the database of heavy metals and radioactivity in teas. With regard to the potential health risk, the percentage of leaching of individual elements in different types of tea infusions was determined, and the assessment of the consumption risk was estimated. Since the calculated exposure factors, namely the HQ (Hazard Quotient) and THQ (Target Hazard Quotient), do not exceed critical levels, teas can still be considered health-beneficial products (most of the radionuclides as well as elements remain in the leaves (65-80%) after brewing).

155Tb production by cyclotrons: what level of 155Gd enrichment allows clinical applications?

BACKGROUND: 155Tb represents a potentially useful radionuclide for diagnostic medical applications, but its production remains a challenging problem, in spite of the fact that many production routes have been already investigated and tested. A recent experimental campaign, conducted with low-energy proton beams impinging on a 155Gd target with 91.9% enrichment, demonstrated a significant co-production of 156gTb, a contaminant of great concern since its half-life is comparable to that of 155Tb and its high-energy γ emissions severely impact on the dose released and on the quality of the SPECT images. In the present investigation, the isotopic purity of the enriched 155Gd target necessary to minimize the co-production of contaminant radioisotopes, in particular 156gTb, was explored using various computational simulations. RESULTS: Starting from the recent experimental data obtained with a 91.9% 155Gd-enriched target, the co-production of other Tb radioisotopes besides 155Tb has been theoretically evaluated using the Talys code. It was found that 156Gd, with an isotopic content of 5.87%, was the principal contributor to the co-production of 156gTb. The analysis also demonstrated that the maximum amount of 156Gd admissible for 155Tb production with a radionuclidic purity higher than 99% was 1%. A less stringent condition was obtained through computational dosimetry analysis, suggesting that a 2% content of 156Gd in the target can be tolerated to limit the dose increase to the patient below the 10% limit. Moreover, it has been demonstrated that the imaging properties of the produced 155Tb are not severely affected by this level of impurity in the target. CONCLUSIONS: 155Tb can be produced with a quality suitable for medical applications using low-energy proton beams and 155Gd-enriched targets, if the 156Gd impurity content does not exceed 2%. Under these conditions, the dose increase due to the presence of contaminant radioisotopes remains below the 10% limit and good quality images, comparable to those of 111In, are guaranteed.

Radionuclide Reporter Imaging to Visualize Tumor Hypoxia Ex Vivo and In Vivo.

In vitro studies using cell culture, including three-dimensional cultures without the involvement of tumor vessels, have limitations in simulating complex intratumoral hypoxic conditions in live subjects. To generate experimental hypoxic conditions closer to those observed in humans in clinical settings, in vivo studies are necessary. In addition, visible light generated via bioluminescence and fluorescence is generally unsuitable for in vivo experiments because of low tissue penetration. Furthermore, near-infrared light (NIR), which has the highest tissue penetration among lights of different wavelengths, cannot be assessed precisely in vivo because of the difficulty in correcting tissue absorption and scatter. For in vivo quantitative analyses, imaging modalities that use high tissue-penetrating signals, such as computed tomography (CT) using X-rays, radionuclide imaging using γ-rays, and magnetic resonance imaging (MRI) using electromagnetic waves, are ideal.Therefore, as an advanced protocol for this research purpose, we provide ex vivo and in vivo methods to investigate the genetic response of multiple copies of hypoxia response elements (HREs) to tumor hypoxia in terms of intensity and intratumoral distribution using a human sodium/iodide symporter (hNIS) reporter gene and radionuclide reporter probes (radioiodine and its chemical analog Tc-99m) based on our previous research. This protocol includes cloning an hNIS reporter construct with multiple copies of HREs, establishing stable cell lines of the reporter construct, preparing a mouse subcutaneous xenograft model, and evaluating the genetic response of multiple HREs to tumor hypoxia using digital autoradiography (ARG) ex vivo and using single-photon emission computed tomography (SPECT) or positron emission tomography (PET) in vivo.

Production of 129mXe and 131mXe via neutron activation of 128Xe and 130Xe at ILL-RHF and NCBJ-MARIA high-flux reactors.

The long-lived xenon isomers 129mXe and 131mXe are of interest for the GAMMA-MRI project, which aims at developing a novel imaging modality based on magnetic resonance of polarized unstable tracers. Here, we present the steps leading to and following the production of these two isomers via neutron irradiation of highly-enriched 128Xe and 130Xe gas samples at two high-flux reactors, the High-Flux Reactor (Réacteur à haut flux, RHF) at the Institut Laue-Langevin (ILL) and the MARIA reactor at the National Centre for Nuclear Research (NCBJ). We describe the experimental setups and procedures used to prepare the stable xenon samples, to open the irradiated samples, and to transfer xenon isomers into reusable transport vials. The activity of 129mXe and 131mXe was measured to be in the range of tens of MBq per sample of 0.8(1)mg, and was proportional to thermal neutron flux density. A small activity of unstable contaminants was also visible in the samples, but their level is not limiting for the GAMMA-MRI project's objectives. In addition, the minimum thermal neutron flux density required to produce 129mXe and 131mXe sufficient for the project could be also determined.

Potential production of Ac-225 at Egyptian second research reactor (ETRR-2) through neutron induced transmutation of Ra-226.

A considerable focus has been paid to the production of 225Ac due to its effective therapeutic action in alpha-targeted radiotherapy. Considering the future global clinical demand, it is necessary to increase the production capacity of 225Ac. A feasibility study was conducted to investigate the production of 225Ac through neutron induced transmutation of 226Ra at the Egyptian Second Research Reactor (ETRR-2) using the MCNPX code. The calculations were carried out for 1 g of 226Ra target exposed to the highest neutron flux in the irradiation grid surrounding the reactor core. The 227Ra, 225Ra, 227Ac, and 225Ac generated activities as a function of irradiation and decay times were estimated. Our study revealed that in this non-linear production process, 39.22 MBq of pure 225Ac could be obtained after three days of irradiation, while 148.74 MBq could be obtained after fifteen days of continuous irradiation.

Early post-treatment MRI predicts long-term hepatocellular carcinoma response to radiation segmentectomy.

OBJECTIVES: Radiation segmentectomy using yttrium-90 plays an emerging role in the management of early-stage HCC. However, the value of early post-treatment MRI for response assessment is uncertain. We assessed the value of response criteria obtained early after radiation segmentectomy in predicting long-term response in patients with HCC. MATERIALS AND METHODS: Patients with HCC who underwent contrast-enhanced MRI before, early, and 12 months after radiation segmentectomy were included in this retrospective single-center study. Three independent radiologists reviewed images at baseline and 1st follow-up after radiation segmentectomy and assessed lesion-based response according to mRECIST, LI-RADS treatment response algorithm (TRA), and image subtraction. The endpoint was response at 12 months based on consensus readout of two separate radiologists. Diagnostic accuracy for predicting complete response (CR) at 12 months based on the 1st post-treatment MRI was calculated. RESULTS: Eighty patients (M/F 60/20, mean age 67.7 years) with 80 HCCs were assessed (median size baseline, 1.8 cm [IQR, 1.4-2.9 cm]). At 12 months, 74 patients were classified as CR (92.5%), 5 as partial response (6.3%), and 1 as progressive disease (1.2%). Diagnostic accuracy for predicting CR was fair to good for all readers with excellent positive predictive value (PPV): mRECIST (range between 3 readers, accuracy: 0.763-0.825, PPV: 0.966-1), LI-RADS TRA (accuracy: 0.700-0.825, PPV: 0.983-1), and subtraction (accuracy: 0.775-0.825, PPV: 0.967-1), with no difference in accuracy between criteria (p range 0.053 to > 0.9). CONCLUSION: mRECIST, LI-RADS TRA, and subtraction obtained on early post-treatment MRI show similar performance for predicting long-term response in patients with HCC treated with radiation segmentectomy. CLINICAL RELEVANCE STATEMENT: Response assessment extracted from early post-treatment MRI after radiation segmentectomy predicts complete response in patients with HCC with high PPV (≥ 0.96). KEY POINTS: • Early post-treatment response assessment on MRI predicts response in patients with HCC treated with radiation segmentectomy with fair to good accuracy and excellent positive predictive value. • There was no difference in diagnostic accuracy between mRECIST, LI-RADS, and subtraction for predicting HCC response to radiation segmentectomy.

Clinical Value of 68Ga-Pentixafor PET/CT in Subtype Diagnosis of Primary Aldosteronism Patients with Adrenal Micronodules.

Our objective was to investigate the clinical value of 68Ga-pentixafor PET/CT in subtype diagnosis of primary aldosteronism (PA) patients with adrenal micronodules less than 1 cm in diameter and compare it with the routine clinical methods. Methods: We used prospective enrollment of PA patients with adrenal micronodules identified by adrenal CT scans to undergo 68Ga-pentixafor PET/CT. Patients were divided into surgically eligible and ineligible groups based on surgical pathology and postoperative follow-up or adrenal venous sampling (AVS) results. Patient management was discussed by a multidisciplinary team. The semiquantitative parameters of PET/CT included SUVmax for adrenal lesion and SUV ratios for lesion to liver and lesion to normal adrenal gland. Results: In total, 123 PA patients with adrenal micronodules were examined using 68Ga-pentixafor PET/CT, and 104 patients who underwent surgery or successful AVS were included in the analysis (48 ± 10 y old). The sensitivity, specificity, and accuracy of visual analysis using 68Ga-pentixafor PET/CT to identify surgically eligible patients were 90.2%, 72.7%, and 86.5%, respectively, which were significantly higher than those of adrenal CT (73.1%, 53.8%, and 68.3%, respectively) and yielded consistent results in different CT morphologic or age subgroups. In 36 patients who had both AVS and 68Ga-pentixafor PET/CT, the tests showed a 66.7% concordance rate. However, PET/CT was significantly more concordant with surgical outcomes than was AVS in 17 patients who underwent adrenalectomy (82.4% vs. 68.86%). Among the 183 adrenal micronodules included in the study, the semiquantitative diagnostic thresholds for 92 lesions eligible for surgical treatment were an SUVmax of at least 4.55, an SUV ratio of at least 2.17 for lesion to liver, and an SUV ratio of at least 1.90 for lesion to normal adrenal gland. All patients benefited from surgical removal of 68Ga-pentixafor-avid microlesions. Conclusion: In PA patients with adrenal micronodules, 68Ga-pentixafor PET/CT demonstrated promising diagnostic accuracy in classification and appeared to perform better than adrenal CT. Furthermore, there was also a suggestion of some potential in predicting postoperative efficacy compared with AVS, although these observations require further investigation and verification in larger cohorts.

Current practice in intermediate risk differentiated thyroid cancer - a review.

Although the overall prognosis for differentiated thyroid cancer (DTC) is excellent, a subset of patients will experience disease recurrence or may not respond to standard treatments. In recent years, DTC management has become more personalized in order to enhance treatment efficacy and avoid unnecessary interventions.In this context, major guidelines recommend post-surgery staging to assess the risk of disease persistence, recurrence, and mortality. Consequently, risk stratification becomes pivotal in determining the necessity of postoperative adjuvant therapy, which may include radioiodine therapy (RIT), the degree of TSH suppression, additional imaging studies, and the frequency of follow-up.However, the intermediate risk of recurrence is a highly heterogeneous category that encompasses various risk criteria, often combined, resulting in varying degrees of aggressiveness and a recurrence risk ranging from 5 to 20%. Furthermore, there is not enough long-term prognosis data for these patients. Unlike low- and high-risk DTC, the available literature is contradictory, and there is no consensus regarding adjuvant therapy.We aim to provide an overview of intermediate-risk differentiated thyroid cancer, focusing on criteria to consider when deciding on adjuvant therapy in the current context of personalized approach, including molecular analysis to enhance the accuracy of patient management.

Efficacy analysis of 125I seeds implantation combined with transcatheter arterial chemoembolization therapy for primary liver cancer / 中华核医学与分子影像杂志

Objective:To explore the clinical efficacy of 125I seeds implantation combined with transcatheter arterial chemoembolization (TACE) in the treatment of primary liver cancer. Methods:A retrospective analysis of data from 40 patients with primary liver cancer at the Northern Theater General Hospital from January 2018 to December 2020 (26 males, 14 females, age 41 to 82 years) was performed. Among them, 21 patients were in treatment group and underwent 125I seeds implantation combined with TACE treatment, while 19 patients were in control group and received TACE treatment. Alpha-fetoprotein (AFP) levels between the two groups were compared, effective rate and disease control rate (DCR) of the two groups were analyzed, and overall survival (OS) and progression-free survival (PFS) were observed. Data were analyzed by using Mann-Whitney U test, χ2 test, Kaplan-Meier method and log-rank test. Results:Two months after 125I seeds implantation, the effective rates of treatment group and control group were 76.19%(16/21) and 8/19, respectively ( χ2=4.83, P=0.028); the DCRs were 90.48%(19/21) and 11/19, respectively ( χ2=4.21, P=0.040). AFP levels in both groups decreased significantly, with treatment group showing a greater decrease rate (0.87(0.84, 0.90) and 0.66(0.65, 0.67); z=5.42, P<0.001). No serious adverse reaction was observed in either group. The median OS of treatment group and control group were 18.2 and 10.6 months, respectively ( χ2=10.98, P=0.037); the median PFS of the two groups were 8.4 and 6.1 months, respectively ( χ2=7.54, P=0.041). Conclusion:125I seeds implantation combined with TACE treatment can exert a synergistic and enhancing effect in the treatment of primary liver cancer.

Multi-parametric MRI combined with 68Ga-PSMA PET/CT for the diagnosis of clinically significant prostate cancer / 中华核医学与分子影像杂志

Objective:To explore whether multi-parametric MRI (mpMRI) combined with 68Ga-prostate specific membrane antigen (PSMA) PET/CT can improve the detection efficiency of clinically significant prostate cancer (csPCa). Methods:Clinical and imaging data of 152 patients (age (68.5±8.5) years) who underwent mpMRI and 68Ga-PSMA PET/CT examination for suspected prostate cancer in the First Affiliated Hospital of the Air Force Medical University from January 2021 to November 2022 were retrospectively analyzed, with the histopathological results from transrectal ultrasound guided biopsy as reference. Lesions with Gleason scores (GS) ≥3+ 4 from the biopsy were diagnosed with csPCa, and lesions with negative biopsy or GS 6 were diagnosed with non-csPCa. MpMRI was evaluated independently by two radiologists according to the Prostate Imaging Reporting and Data System (PI-RADS) version 2.1. The radioactive uptake of 68Ga-PSMA PET/CT in prostate lesions was evaluated by SUV max. The independent-sample t test, Mann-Whitney U test and χ2 test were used to compare differences between the two groups, and then multivariate logistic regression analysis was performed. ROC curves analysis was used to analyze the diagnostic efficacies of individual and combined factors and Delong test was used. Results:There were 85 csPCa and 67 non-csPCa confirmed. Prostate specific antigen (PSA), PI-RADS score and SUV max were significantly different between the csPCa group and the non-csPCa group ( χ2=68.06, U values: -7.66, -8.98, all P<0.001). Multivariate logistic regression analysis indicated that PI-RADS score (odds ratio ( OR)=3.424, 95% CI: 1.651-7.100) and SUV max ( OR=1.931, 95% CI: 1.403-2.658) were independent predictors of csPCa (both P<0.001). ROC curves analysis revealed that the cut-off value for diagnosing csPCa was 4 for PI-RADS score and 5.6 for SUV max. The accuracy of mpMRI and PET/CT alone in csPCa diagnosis was 80%(122/152) (AUC of 0.789(95% CI: 0.711-0.866) with the sensitivity and specificity of 91%(77/85) and 67%(45/67)), and 87%(132/152) (AUC of 0.876(95% CI: 0.817-0.936) with the sensitivity and specificity of 81%(69/85) and 94%(63/67)), respectively. Several joint models incorporating 68Ga-PSMA PET/CT with mpMRI data were investigated, the model of PI-RADS 5 or PI-RADS 3-4 and SUV max>5.6 showed better performance than mpMRI and PET/CT alone and other joint models ( z values: 2.01-3.64, all P<0.05), with the accuracy of 91%(138/152) (AUC of 0.910(95% CI: 0.857-0.962) with the sensitivity and specificity of 89%(76/85) and 93%(62/67)). Conclusion:MpMRI combined with 68Ga-PSMA PET/CT can significantly improve the detection efficiency of csPCa, with the principal effect being improved in risk stratification of PI-RADS 3-4 lesions in mpMRI.