Liver Volume Research Articles

Radiotherapy as a metastasis directed therapy for liver oligometastases - comparative analysis between CT-guided interstitial HDR brachytherapy and two SBRT modalities performed on double-layer and single layer LINACs

IntroductionSurgical resection is gold standard for treatment of liver metastasis, locally ablative techniques including computer tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy (CT-BRT) and stereotactic body radiotherapy (SBRT) have gained prominence as alternatives, offering comparable outcomes in selected patients. We aim to compare CT-BRT and SBRT - based on dosimetric analysis.Material and methodsPatients who underwent CT-BRT for oligometastatic, ≤4cm liver metastases between 2018 and 2024 were eligible. SBRT plans for Halcyon (SBRTh) and TrueBeam (SBRTtb) were prepared virtually. In the CT-BRT group CTV was equal to PTV, for SBRTh and SBRTtb planning, a 5 mm margin was applied to CTV to create PTV. Dose calculation was carried out with the TG-43 algorithm for CT-BRT and Anisotropic Analytical Algorithm for SBRTh and SBRTtb group. Descriptive statistics were used to compare the data. The Wilcoxon pairwise order test was utilized to compare dependent groups.ResultsCT-BRT resulted in a more favorable dose distribution within PTVs for Dmean, D50, and D90, while SBRT showed better results for D98 and V27.5Gy. No significant differences were observed for V25Gy between CT-BRT and SBRTtb, but SBRTh favored over CT-BRT. For OARs, CT-BRT plans showed better values for V5, V10, and V11.6Gy in the uninvolved liver volume. There were no significant differences in dose distribution for the duodenum, bowel, and heart. SBRT modalities performed better in the kidney. CT-BRT had improved dose distribution in the esophagus, great vessels, ribs, skin, spinal cord, and stomach compared to SBRT.ConclusionsCT-BRT could be a viable alternative to SBRT for certain patients with liver malignancies.

New criteria for preoperative liver function assessment with safety margins to avoid postoperative mortality during liver resection for hilar cholangiocarcinoma.

BackgroundDespite recent medical advancements, surgery for hilar cholangiocarcinoma is associated with high complication and mortality rates. This may be partly attributed to the absence of established preoperative liver evaluation criteria for safe surgery. This study aimed to propose a reliable indicator for safe and well-planned management of major hepatectomy with extrahepatic bile duct resection. MethodsWe included 150 patients who underwent major hepatectomy with extrahepatic bile duct resection between 2013 and 2021 in Japan. The risk factors for post-hepatectomy liver failure (PHLF) were retrospectively analyzed. ResultsPHLF was observed in 24 (16.0%) patients who underwent major hepatectomy with extrahepatic bile duct resection. In the multivariate analysis, the identified risk factors for PHLF were the ratio of future remnant liver volume to total liver volume (FRLV/TLV) ≤ 42% and indocyanine green clearance fraction of the future remnant liver (ICGK-F) ≤ 0.07. Patients with these two factors were significantly associated with PHLF compared with those with either one or none of the risk factors (60.0% vs 15.1% and 8.1%, respectively). ConclusionsThe combinational use of ICGK-F and FRLV/TLV is useful for preoperative liver function assessment with a safety margin to avoid PHLF and postoperative mortality in hepatectomy for hilar cholangiocarcinoma.

Transileocolic Portal Vein Embolization Increases Remnant Liver Volume After Major Hepatectomy.

Transileocolic portal vein embolization (TIPE) may reduce the risk of liver failure after massive hepatectomy. However, convincing evidence of its usefulness in this regard is yet to be reported. Therefore, this study aimed to investigate the use of TIPE after massive hepatectomy. Twelve patients who underwent TIPE were included. Pre- and postoperative liver volumetry was determined using a 3D simulator with computed tomography. After TIPE, the percent change in total liver volume was 104.0%±13.1% (p=0.08). Conversely, the percent increase in remnant liver volume (ml)/total liver volume (ml) and remnant liver volume (ml)/standard liver volume (ml) was 122.9%±18.6% (p<0.001) and 132.2%±19.6% (p<0.001), respectively. TIPE operation time was 125±84.6 min, with minimal blood loss in all cases. Postoperative hospitalization duration during TIPE was 4.5±2.6 days. No TIPE-related complications occurred in any patient. TIPE is beneficial and safe when preoperative volumetry indicates that the remaining liver volume is inadequate and inoperable.

Holmium-166 radioembolisation dosimetry in HCC.

To evaluate dosimetry, dose-response and dose-toxicity relationships for holmium-166 (166Ho) radioembolisation in patients with hepatocellular carcinoma (HCC). Thirty-one patients with hepatocellular carcinoma were included in the HEPAR Primary study (NCT03379844, registered on December 20th, 2017) and underwent 166Ho-microspheres radioembolisation. Linear mixed models assessed the association between tumour absorbed doses and response based on mRECIST both on tumour and patient level. Preliminary tumour absorbed dose thresholds were estimated based on predictive value. Linear regression models assessed the association between non-tumour absorbed dose and Common Terminology Criteria for Adverse Events version 4.03. Median tumour absorbed dose (tumour level) was 95.5 Gy (range 44-332 Gy). Median non-tumour absorbed dose based on whole liver volume was 19 Gy (range 3 - 48 Gy) and based on target liver volume was 30 Gy (range 13 - 54 Gy). There was a significant association between non-tumour absorbed dose and toxicity. Tumours with partial response/complete response (PR/CR, responders) received a 41% higher absorbed dose than tumours with progressive disease/stable disease (PD/SD, non-responders) (95%CI: 2%-93%, p = 0.04). A predictive value of 90% for tumour response was observed at a tumour absorbed dose threshold of 155 Gy, 100% predictive value was achieved at 184.5 Gy. This study confirms a positive relationship between tumour absorbed dose and response and between non-tumour absorbed dose and toxicity. Dose thresholds found in this study can serve as a basis for personalized dosimetry in HCC patients treated with 166Ho-microspheres.

Treatment Planning Comparison of Gantry-based and Fixed Beams for the Treatment of Liver Tumors With Carbon Ion Therapy.

This study aimed to compare the use of a rotating gantry in liver tumor carbon-ion radiotherapy using of a fixed-port for treatment planning. Thirty patients with liver tumors were analyzed. Three treatment plans were developed for each case: one with a rotating gantry with a 360° angle, one with fixed ports of 0° and 90° with a ±20° couch rolling setting, and one with fixed ports of 45° and 90° with a ±20° couch rolling setting. The dose-volume histogram parameters of the clinical target volume (CTV) and organs at risk (OARs) for each treatment plan were compared. Significant differences in the volume of the liver-gross tumor volume (GTV) of normal liver irradiated with 5 Gy to 15 Gy were found between the gantry treatment plans and fixed-port treatment plans. There were no significant differences in the OARs, except for the CTV and liver GTV, between the gantry and fixed-port treatment plans. The study results support the potential of using a rotating gantry to reduce liver doses, especially in the low-to-medium dose range, while maintaining target and OAR doses except for the liver. A rotating gantry could be especially useful in cases in which the relationship between the tumor and OAR is complicated by location.

Combined preoperative albumin bilirubin score and hepatectomy percentage for evaluate the liver regeneration after partial hepatectomy

Surgical resection is a pivotal therapeutic approach for addressing hepatic space-occupying lesions, with liver volume restoration and hepatic functional recovery being crucial for assessing surgical prognosis. The preoperative albumin-bilirubin (ALBI) score, encompassing serum albumin and bilirubin levels, can be determined via blood analysis, effectively mitigating human error and providing an accurate depiction of liver function. The hepatectomy ratio, which is the proportion of the liver volume removed to the total liver volume, is critical in preserving an adequate liver tissue volume to ensure postoperative hepatic functional compensation, minimize surgical complications, and reduce mortality rates. Incorporating the preoperative ALBI score and hepatectomy ratio aids surgeons in assessing the optimal timing and extent of partial hepatectomy. The introduction of preoperative albumin bilirubin score and hepatectomy percentage is beneficial for the surgeons to evaluate the timing and magnitude of partial liver resection.

Influence of major hepatectomy on gemcitabine-based chemotherapy for recurrent biliary tract cancer after surgery: a subgroup analysis of JCOG1113.

Major hepatectomy (MH) can increase the risk of adverse events (AEs) owing to impaired drug metabolism due to decreased liver volume and surgical injury. Thus, we performed this subgroup analysis using data from JCOG1113, a phase III trial comparing gemcitabine plus S-1 (GS) and gemcitabine plus cisplatin (GC) in patients with advanced and recurrent biliary tract cancer (BTC), to evaluate the effect of MH on the safety and efficacy of GC and GS regimens in patients with recurrent BTC. Of the 354 patients with advanced BTC enrolled in JCOG1113, 76 patients with postoperative recurrence (30 in the MH group and 46 in the non-MH group) were analyzed. Grade ≥ 3 platelet count decreased in both arms was more frequent in the MH group than in non-MH group (GC, 0.0 vs. 17.6%; GS, 3.9 vs. 15.4%). However, in the MH group, the white blood cell decreased (GC, 55.0 vs. 38.5%; GS, 23.1 vs. 7.7%) and anemia (GC, 15.0 vs. 11.8%; GS, 23.1 vs. 7.7%) were less common than in the non-MH group. The MH and non-MH groups showed no significant difference in overall survival (OS) in both GC [median OS, 23.0 in MH vs. 16.9months in non-MH (hazard ratio, 0.857; 95% CI 0.387-1.899)], and GS [median OS, 21.5 vs. 14.9months (hazard ratio, 0.670; 95% CI 0.310-1.447)] arms. The safety and efficacy of gemcitabine-based chemotherapy were comparable between patients who underwent MH and those who underwent other surgeries.

Lung volumes are increased in fetuses with transposition of the great arteries on intrauterine MRI.

Fetal brain size is decreased in some children with complex CHDs, and the distribution of blood and accompanying oxygen and nutrients is regionally skewed from early fetal life dependent on the CHD. In transposition of the great arteries, deoxygenated blood preferentially runs to the brain, whereas the more oxygenated blood is directed towards the lungs and the abdomen. Knowledge of whether this impactsintrauterine organ development is limited. We investigated lung, liver, and total intracranial volume in fetuses with transposition of the great arteries using MRI.Eight fetuses with dextro-transposition and without concomitant disease or chromosomal abnormalities and 42 fetuses without CHD or other known diseases were scanned once or twice at gestational age 30 through 39 weeks. The MRI scans were conducted on a 1.5T system, using a 2D balanced steady-state free precession sequence. Slices acquired covered the entire fetus, slice thickness was 10 mm, pixel size 1.5 × 1.5 mm, and scan duration was 30 sec.The mean lung z score was significantly larger in fetuses with transposition compared with those without a CHD; mean difference is 1.24, 95% CI:(0.59;1.89), p < 0.001. The lung size, corrected for estimated fetal weight, was larger than in the fetuses without transposition; mean difference is 8.1 cm3/kg, 95% CI:(2.5;13.7 cm3/kg), p = 0.004.In summary, fetuses with dextro-transposition of the great arteries had both absolute and relatively larger lung volumes than those without CHD. No differences were seen in liver and total intracranial volume. Despite the small number of cases, the results are interesting and warrant further investigation.

Incremental impact of organ allocation changes and machine perfusion technology on liver transplant waitlist and volumes

Incremental impact of organ allocation changes and machine perfusion technology on liver transplant waitlist and volumes

Mesenteric Vein to Gonadal Vein Shunt Embolization in Patients with Portal Hypertension: Technical Considerations and Clinical Outcomes.

To assess the technical and clinical outcomes of percutaneous embolization for high-flow mesenteric vein to gonadal vein (MGV) portosystemic shunts. In this HIPPA-compliant, review board-approved study, patients who underwent embolization of MGV shunts between 2011 and 2023 were included. Patient demographic data, embolization technique, clinical outcomes, and complications were retrieved from the electronic health records. Technical success was defined as complete occlusion of the shunt on follow-up imaging. Clinical outcomes assessed were resolution/improvement of hepatic encephalopathy, improvement in liver function, changes to liver volumes, and occurrence of adverse events. Eight patients (mean age 59.5, 75% female) with nine MGV shunts were included. The indications for shunt embolization included medically refractory hepatic encephalopathy, bleeding duodenal varices, and transplant liver dysfunction. The mean maximum shunt diameter was 23.3mm. Embolization was most commonly performed with a combination of coils and N-butyl cyanoacrylate or vascular plugs. Complete MGV shunt thrombosis was achieved in 7/9 shunts post-embolization, and symptom improvement was noted in 7/8 patients. Child-Pugh scores improved post-embolization in 6/9 patients by a median of 3 points. Liver volumes also increased by a mean of 20.8 ± 17.7% post-embolization. Minor adverse events included new onset ascites, partial mesenteric/portal vein thrombosis, and new gastroesophageal varices without bleeding in four patients. Embolization of MGV shunts is technically feasible and effective for treatment of hepatic encephalopathy and increasing hepatopetal portal perfusion. There was an improvement in Child-Pugh scores and an increase in liver volumes in the majority of patients post-embolization.

Uninvolved liver dose prediction in stereotactic body radiation therapy for liver cancer based on the neural network method.

The quality of a radiotherapy plan often depends on the knowledge and expertise of the plan designers. To predict the uninvolved liver dose in stereotactic body radiotherapy (SBRT) for liver cancer using a neural network-based method. A total of 114 SBRT plans for liver cancer were used to test the neural network method. Sub-organs of the uninvolved liver were automatically generated. Correlations between the volume of each sub-organ, uninvolved liver dose, and neural network prediction model were established using MATLAB. Of the cases, 70% were selected as the training set, 15% as the validation set, and 15% as the test set. The regression R-value and mean square error (MSE) were used to evaluate the model. The volume of the uninvolved liver was related to the volume of the corresponding sub-organs. For all sets of R-values of the prediction model, except for Dn0 which was 0.7513, all R-values of Dn10-Dn100 and Dnmean were > 0.8. The MSE of the prediction model was also low. We developed a neural network-based method to predict the uninvolved liver dose in SBRT for liver cancer. It is simple and easy to use and warrants further promotion and application.

Organ-Specific Iron Overload in Non-Transfusion-Dependent Thalassemia Patients: Insights from Quantitative MRI Evaluation

ObjectiveTo elucidate the iron load in different organs of non-transfusion-dependent thalassemia (NTDT) patients using magnetic resonance imaging (MRI) T2* scan. MethodsThirty-four NTDT patients, including 28 NTDT iron chelation without and 6 NTDT with iron chelation, together with 15 normal controls, underwent MRI examination between December 2022 and July 2024 were enrolled in the study. Measured T2* of the pituitary gland, kidney cortex, heart, liver, pancreas, spleen. Liver and spleen volumes were evaluated. ResultsOf the 28 patients in NTDT without iron chelation group, 19 patients with iron overload in the liver, 9 patients with iron overload in the kidneys, and 4 patients with iron overload in the spleen. Most patients with abnormal kidney and spleen iron (76.9 %) had liver iron overload. Compared with the control group, NTDT without iron chelation patients had lower T2* in the liver, kidney, and spleen (p < 0.05). And heart T2* was correlated with kidney T2* (r = 0.480, p = 0.010) and pancreas (r = 0.411, p = 0.037). Liver T2* was correlated with spleen T2* (r = 0.479, p = 0.011). Pancreas T2* was correlated with pituitary T2* (r = -0.433, p = 0.031). ConclusionsNTDT patients exhibit significant organ-specific iron overload, particularly in the liver, kidneys, and spleen. The correlations between iron levels in different organs suggest interconnected mechanisms of iron accumulation. These findings highlight the importance of regular MRI screening to monitor and manage iron overload in NTDT patients.

Evaluation of the prognostic effectiveness of liver metastasis volume by volumetric measurement in colorectal cancer.

Aim: To evaluate the relationship between liver metastasis volume and survival in colorectal cancer patients using the volumetric measurement method.Methods: 114 colorectal cancer patients with isolated liver metastases were included in the study. Liver tumor volume, total liver volume were calculated from the patients images at the time of diagnosis. Vitrea 7.14 imaging software was used for liver volume analysis and volume analysis of each metastasis.Results: Median overall survival(OS) in the group with tumor volume <42ml3 was 30.98months In the group with tumor volume ≥42ml3, median OS was 16.36months (p: 0.001). In patients who underwent metastasectomy, the median OS in the group with a tumor volume <42ml3 was 52.3months, the median OS in the group with a tumor volume ≥42ml3 was 22.2months. In patients who did not undergo metastasectomy, the median OS in the <42ml3 group was 20.23months, the median OS in the ≥42ml3 group was 15.63months.Conclusion: In our study, we found that liver metastasis volume was prognostic for OS. It is argued that tumor volume measurement by volumetric measurement is a widely used method in the decision for metastasectomy in liver metastatic colorectal cancer patients.

An anatomical analysis of liver volume and quality by ethnicity in a New Zealand population.

Post-hepatectomy liver failure is a major cause of mortality, where future liver remnant (FLR) is the key controllable factor. Recommended minimum FLR is influenced by quality of liver parenchyma. Historical research has often failed to include Māori and Pacific Island (PI) populations despite worse health outcomes. Liver analysis by ethnicity is one such example of this. The aims were to determine digital FLR for various anatomical hepatectomies, investigate any correlations between computed tomography (CT) hepatic textural analysis and body mass index (BMI); and assess the variance of these relationships for different ethnicities. One hundred and fifty-one patients who underwent abdominal CT scans at Burwood Hospital, Christchurch were retrospectively analysed. Māori and PI patients were selectively recruited to represent New Zealand's diversity. Liver volumetry, segmental ratio, and intra-hepatic fat deposits (IHFD) per ethnicity were examined. Median age of the cohort was 66 (19-95) and 75 (50%) were males. 68%, 23% and 9% patients identified as being European, Māori/PI and Asian, respectively. No statistically significant difference in volume or segment/total volume ratio were noted across different ethnicities. Obese patients had higher IHFD compared with overweight and normal BMI groups. When stratified across ethnic groups, higher IHFD were observed in Asian compared with Māori/PI populations, despite lower BMI. No significant variances in liver volumetry were found across different ethnic groups in New Zealand. However association between BMI and IHFD varied across different ethnic cohorts. Consequently, knowledge of liver volumetry is not enough; patient liver quality and ethnicity should considered for hepatic-surgery planning.

Comparison of T1 Mapping on Gadoxetic Acid-Enhanced Magnetic Resonance Imaging With Conventional Functional Liver Reserve Indices and Technetium-99m Galactosyl Serum Albumin Scintigraphy.

Background Gadoxetic acid (EOB)-enhanced magnetic resonance imaging (MRI) (EOB-MRI) can be used as a one-stop examination for detecting liver tumors and evaluating liver function. Purpose The study aimed to assess the functional liver reserve (FLR) using the T1 map from the hepatobiliary phase of EOB-MRI by conducting a comparison with the results of conventional FLR tests and the technetium-99m (99mTc)-galactosyl serum albumin (GSA) scintigraphy. Materials and methods The retrospective data from 43 patients were included in the study. The regions of interest covered the entire liver. The data acquired from each EOB-MRI slice were summed to derive voxel-by-voxel values. The average sum of the T1 values (pre- and post-enhancement), ∆T1, and ∆T1 ratios were calculated. The HH15, LHL15, and LU15 values were calculated from the GSA scintigraphy. The results of conventional FLR tests, such as the indocyanine green retention rate at 15 min (ICGR15), the Child-Pugh classification (CPC), and the albumin-bilirubin (ALBI) and albumin-indocyanine green evaluation (ALICE) scores, were obtained. Results The T1 pre- and post-sum values showed a weak correlation with the LHL15 (r=0.36 and 0.38, respectively). A strong correlation was observed between the liver volume and the T1 pre- and post-sum values (r=0.86 and 0.76, respectively). A moderate correlation was observed between the T1 mean and the ALBI and ALICE values (r=0.58 and 0.49, respectively) and between the ∆T1 ratio and the CPC, ALBI, and ALICE values (r=-0.40, 0.58, and -0.55, respectively). The T1 post-sum values showed a moderate correlation with the ALBI scores (r=0.47) and a weak correlation with the ALICE scores (r=0.38). Furthermore, the LU15 values showed a weak correlation with the ICGR15 and model for end-stage liver disease (MELD) scores (r=-0.32 and -0.34, respectively). Conclusions Representative indices, such as the T1 mean and ∆T1 ratio, demonstrated a better relationship with conventional FLR indices compared with volumetric radiological indices. Therefore, we propose that the T1 post-sum can be used as an FLR index.

Clinical evidence of low-calorie and ketogenic nutrological therapy before, during and after bariatric surgery: a systematic review

Introduction: Obesity is a multifactorial disease that causes serious comorbidities. There are more than 2.2 billion overweight and obese people in the world. Obese patients tend to be predisposed to micronutrient deficiency even before bariatric surgery, therefore, it is imperative to supplement nutrients orally, enterally, or parenterally, according to the indications of each patient. Objective: It was highlighted the importance of low-calorie and ketogenic nutritional therapy before, during, and after bariatric surgery through the systematic analysis of clinical studies. Methods: The systematic review rules of the PRISMA Platform were followed. The search was conducted from June to July 2024 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: 119 articles were found. A total of 40 articles were fully evaluated and 34 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 23 studies with a high risk of bias and 27 that did not meet GRADE and AMSTAR-2. Most studies presented homogeneity in their results, with X2=76.5%&gt;50%. It was concluded that nutrological therapy strategies could represent a possible alternative to other methodologies, especially when it is recommended to improve patient adherence to following the prescribed diet before bariatric surgery. Weight loss induced by the ketogenic diet before bariatric surgery has beneficial effects on reducing liver volume, metabolic profile, and intra- and postoperative complications. Knowledge of the type of bariatric surgery performed and an understanding of its anatomy and physiology are useful to provide optimal care to patients, especially in nutritional complications. Nutritional deficiencies and metabolic disorders result from “malabsorption” procedures such as RYGB. Immediate administration of thiamine is essential. Dextrose should be avoided in intravenous hydration until thiamine is adequately replaced. For all bariatric patients, a protein intake of 60-70 g/d and a multivitamin with iron and vitamin B12 supplementation is recommended. Daily calcium and vitamin D supplementation is also encouraged. In addition, serum micronutrient levels should be monitored regularly and additional supplementation should be prescribed as indicated.

The Relationship of the Lower Ribcage with Liver and Gut Size: Implications for Paleoanthropology

Organ–skeleton relationships are understudied in biological anthropology. The torso skeleton is often used to infer the organ size and evolution in hominins; ribcage “types”, in particular, are used to infer the abdominal organ size in hominins. This study is a quantitative examination of the relationship between the lower ribcage and two organs: the liver and the intestines (“gut”) in humans. Specifically, we test whether the ribcage breadth, shape, and “flare”, at the level of rib 10, covaries with the liver volume and gut volume in Homo sapiens. Liver size, gut size, and ribcage measurements are taken from CT scans (N = 61). The results show sex differences in the gut–ribcage relationship. The gut volume is associated with ribcage breadth and flare in both sexes. The liver volume is not associated with any ribcage measurements. We conclude that sex differences in the organ–skeleton relationship complicate the previous simplistic view that the size of the liver or the gut could be inferred through a fossil’s ribcage type. Biological anthropologists should continue to explore sex differences in organ–skeleton relationships, when attempting to understand the evolution of visceral organs and the torso.

Long-Term Changes in Liver and Kidney Cyst Volumes following Foam Sclerotherapy

Long-Term Changes in Liver and Kidney Cyst Volumes following Foam Sclerotherapy

Correlation of Total Kidney Volume (TKV), Total Liver Volume (TLV), and Combined TKV and TLV with Abdominal Symptoms in Autosomal Dominant Polycystic Kidney Disease (ADPKD)

Correlation of Total Kidney Volume (TKV), Total Liver Volume (TLV), and Combined TKV and TLV with Abdominal Symptoms in Autosomal Dominant Polycystic Kidney Disease (ADPKD)

Species specific kinetics of imidacloprid and carbendazim in mouse and rat and consequences for biomonitoring

This study aimed to develop physiologically based kinetic (PBK) models to predict the blood concentrations of imidacloprid and carbendazim and their primary metabolites 5-hydroxy-imidacloprid and 2-aminobenzimidazole after single or repeated oral exposure in mouse (Mus musculus), and compare this to corresponding kinetic data in rat (Rattus norvegicus). PBK model constants for conversion of imidacloprid and carbendazim and formation and clearance of their selected primary metabolites were quantified by in vitro mouse liver microsomal and S9 incubations. The performance of the newly developed PBK models was evaluated, based on a comparison to available literature data, showing that the models performed well. Predictions made were also compared to results from PBK model simulations for rats reported previously to obtain insight in species dependent differences in kinetics of these pesticides. The results thus obtained revealed substantial species differences in kinetics for these two pesticides between mouse and rat, especially for imidacloprid and to a lesser extent for carbendazim. Repeated dose PBK model simulations revealed that the models can facilitate estimation of external exposure levels under wildlife conditions based on internal blood concentrations of the parent compound. The rate of conversion and liver volume fraction were shown to influence the accuracy of these predictions with lower values providing less variable outcomes. It is concluded that PBK modeling provides a new approach methodology of use for wildlife biomonitoring studies and that results of the present study facilitate benchmarking of the species and compounds for which kinetics enable this with sufficient accuracy.