Hypofractionated radiation therapy combined with androgen deprivation therapy for high-risk localized prostate cancer

INTRODUCTION

This study aimed to analyse the treatment outcomes of moderately hypofractionated radiation therapy (RT) combined with androgen deprivation therapy (ADT) and the prognostic implications of prostate-specific antigen (PSA) kinetics in high-risk localized prostate cancer.

METHODS

The medical records of 140 patients who underwent definitive RT (70 Gy in 28 fractions) combined with ADT were retrospectively reviewed. ADT consists of a gonadotropin-releasing hormone agonist and an anti-androgen. Clinical outcomes included the biochemical failure rate (BFR), clinical failure rate (CFR), overall survival (OS) and prostate cancer-specific survival (PCSS). The BFR and CFR were stratified by the PSA nadir and the time to the PSA nadir, respectively. Acute and late genitourinary and gastrointestinal adverse events were also recorded.

RESULTS

The 5-year BFR, CFR, OS and PCSS rates were 9.8%, 4.5%, 90.2% and 98.7%, respectively. Ninety-five (67.9%) patients achieved a PSA nadir of 0.01 ng/mL. Patients with a PSA nadir >0.01 ng/mL had a significantly higher BFR and CFR (BFR, P = 0.001; CFR, P = 0.027), even after adjusting for other prognostic factors [per 0.1 ng/mL; BFR, hazard ratio (HR) 4.440, P < 0.001; CFR, HR 4.338, P = 0.001]. However, the time to the PSA nadir and pre-RT PSA were not significantly associated with the BFR and CFR. Six patients (4.3%) reported grade 3 late adverse events, mostly haematuria and haematochezia.

CONCLUSION

Definitive RT with moderate hypofractionation combined with long-term ADT showed good efficacy for high-risk localized prostate cancer. The lowest PSA nadir was significantly associated with a low recurrence rate, indicating the importance of PSA follow-up.

Risk Factors Affecting Clinical Outcomes of Low-risk Early-stage Human Papillomavirus-Associated Endocervical Adenocarcinoma Treated by Surgery Alone: Application of Silva Pattern

This study aimed to report the clinical outcomes and risk factors for survival of patients with low-risk early-stage human papillomavirus-associated (HPVA) endocervical adenocarcinoma (EAC) treated with surgery alone. This retrospective study obtained the clinicopathological data of patients with early-stage HPVA EAC who underwent surgery between 2012 and 2018. The Silva pattern of invasion was determined by reviewing pathology slides. Locoregional recurrence-free survival (RFS), RFS, and overall survival were calculated, and the risk factors for survival were analyzed. One hundred seventeen patients with a median follow-up of 5.2 years (0.5-9.7 yr) were included. The most common histologic type was usual (94/117, 80.3%). The Silva pattern was A in 79 patients (67.5%), B in 30 (25.6%), and C in 8 (6.8%). The 5-year locoregional RFS, RFS, and overall survival rates were 92.4%, 87.8%, and 97.2%, respectively. The presence of intermediate-risk factors and Silva pattern C were significantly associated with worse survival. Based on these findings, patients were categorized into 2 groups: Group 1 (Silva pattern A or Silva pattern B without intermediate-risk factors) and Group 2 (Silva pattern B with intermediate-risk factors or Silva pattern C). Group 2 showed significantly worse outcomes than Group 1, including the 5-year locoregional RFS (98.6% vs 68.0%), RFS (96.4% vs 54.6%), and overall survival (100.0% vs 86.5%). In conclusion, surgery alone for early-stage HPVA EAC resulted in favorable outcomes. Consideration of the Silva pattern, in addition to well-known risk factors, could help in precise risk group stratification of low-risk, early-stage HPVA EAC.

Long-term findings of rectal endoscopy and rectal bleeding after moderately hypofractionated, intensity-modulated radiotherapy for prostate cancer

To present rectal endoscopic findings and toxicity after definitive moderately hypofractionated, intensity-modulated radiotherapy (IMRT) for prostate cancer. We retrospectively reviewed patients who underwent IMRT for prostate cancer and underwent post-radiotherapy endoscopies between 2008 and 2018. Endoscopic findings were reviewed and graded using Vienna Rectoscopy Score (VRS). We have analyzed the association between endoscopic findings and rectal bleeding, and investigated risk factors for rectal bleeding. Total 162 patients met the inclusion criteria of this study. There was a trend of VRS worsening during the initial 3 years after radiotherapy followed by recovery. Rectal bleeding was highest at 1 year after radiotherapy and improved thereafter. The 5-year cumulative incidence of grade ≥ 2 rectal bleeding was 14.8%. In the multivariable Cox regression analysis, cardiovascular disease (hazard ratio [HR] 2.732, P = 0.037), rectal wall V65 (HR 1.158, P = 0.027), and VRS ≥ 3 in first post-radiotherapy endoscopy (HR 2.573, P = 0.031) were significant risk factors for rectal bleeding. After IMRT for prostate cancer, VRS and rectal bleeding worsened over 1-3 years after radiotherapy and recovered. Cardiovascular disease, rectal wall V65, and VRS ≥ 3 in first post-radiotherapy endoscopy were significant risk factors for rectal bleeding.

Prostate-specific antigen kinetics in hypofractionated radiation therapy alone for intermediate- and high-risk localized prostate cancer

Background

This study aimed to evaluate the treatment outcomes and define the prostate-specific antigen (PSA) kinetics as potential prognostic factors in patients with intermediate- or high-risk localized prostate cancer (PCa) who underwent moderately hypofractionated radiation therapy.

Methods

The study retrospectively reviewed the medical records of 149 patients with intermediate- or high-risk localized PCa who underwent definitive radiation therapy (70 Gy in 28 fractions) without androgen deprivation therapy. Clinical outcomes were analyzed based on risk stratification (favorable-intermediate, unfavorable-intermediate, and high-risk). The biochemical failure rate (BFR) and clinical failure rate (CFR) were stratified based on the PSA nadir and the time to the PSA nadir to identify the prognostic effect of PSA kinetics. Acute and late genitourinary and gastrointestinal adverse events were analyzed.

Results

Significant differences were observed in the BFR and CFR according to risk stratification. No recurrence was observed in the favorable intermediate-risk group. The 7-year BFR and CFR for the unfavorable intermediate-risk and high-risk groups were 19.2% and 9.8%, and 31.1% and 25.3%, respectively. Patients with a PSA nadir >0.33 ng/mL or a time to the PSA nadir <36 months had a significantly greater BFR and CFR. The crude rate of grade 3 late adverse events was 3.4% (genitourinary: 0.7%; gastrointestinal: 2.7%). No grade 4-5 adverse event was reported.

Conclusion

A significant difference in clinical outcomes was observed according to risk stratification. The PSA nadir and time to the PSA nadir were strongly associated with the BFR and CFR. Therefore, PSA kinetics during follow-up are important for predicting prognosis.

Radiotherapy trend in elderly hepatocellular carcinoma: retrospective analysis of patients diagnosed between 2005 and 2017

PURPOSE

To report the trends of radiotherapy in the management of elderly patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

We retrospectively reviewed patients who entered HCC registry of Samsung Medical Center between 2005 and 2017. Patients who were 75 years or older at the time of registration were defined as elderly. They were categorized into three groups based on the year of registration. Radiotherapy characteristics were compared between the groups to observe differences by age groups and period of registration.

RESULTS

Out of 9,132 HCC registry patients, elderly comprised 6.2% (566 patients) of the registry, and the proportion increased throughout the study period (from 3.1% to 11.4%). Radiotherapy was administered to 107 patients (18.9%) in elderly group. Radiotherapy utilization in the early treatment process (within 1 year after registration) has rapidly increased from 6.1% to 15.3%. All treatments before 2008 were delivered with two-dimensional or three-dimensional conformal radiotherapy, while more than two-thirds of treatments after 2017 were delivered with advanced techniques such as intensity-modulated radiotherapy, stereotactic body radiotherapy, or proton beam therapy. Overall survival (OS) of elderly was significantly worse than younger patients. However, for patients who received radiotherapy during the initial management (within one month after registration), there was no statistically significant difference in OS between age groups.

CONCLUSION

The proportion of elderly HCC is increasing. Radiotherapy utilization and adoption of advanced radiotherapy technique showed a consistently increasing trend for the group of patients, indicating that the role of radiotherapy in the management of elderly HCC is expanding.

Role of salvage radiotherapy for recurrent ovarian cancer

OBJECTIVE

This study aimed to report clinical outcomes of salvage radiotherapy for recurrent ovarian cancer and identify predictors of clinical outcomes.

METHODS

We retrospectively reviewed data of patients who received salvage radiotherapy for recurrent ovarian cancer between January 2011 and June 2021. Stereotactic body radiotherapy, involved-field radiotherapy with conventional fractionation, and non-involved-field radiotherapy with conventional fractionation were included in this study. Local failure-free survival, progression-free survival, chemotherapy-free survival, and overall survival were assessed. Additionally, potential prognostic factors for survival were analyzed.

RESULTS

A total of 79 patients were included with 114 recurrent lesions. The median follow-up was 18.3 months (range 1.7-83). The 2-year local failure-free survival, progression-free survival, chemotherapy-free survival, and overall survival rates were 80.7%, 10.6%, 21.2%, and 74.7%, respectively. Pre-radiotherapy platinum resistance (hazard ratio (HR) 3.326, p<0.001) and short pre-radiotherapy CA-125 doubling time (HR 3.664, p<0.001) were associated with poor chemotherapy-free survival. The 1-year chemotherapy-free survival rates of patients with both risk factors, a single risk factor, and no risk factor were 0%, 20.4%, and 53.5%, respectively. The difference between risk groups was statistically significant: low risk versus intermediate risk (p<0.001) and intermediate risk versus high risk (p<0.001).

CONCLUSIONS

Salvage radiotherapy for recurrent ovarian cancer resulted in local control with improved chemotherapy-free survival in carefully selected patients. Our results suggest that the consideration of pre-radiotherapy platinum resistance and pre-radiotherapy CA-125 doubling time could help with patient selection.

Patterns and risk factors of recurrence in low-risk early-stage cervical adenocarcinoma treated with surgery alone: implications on risk group stratification

OBJECTIVE

Cervical adenocarcinoma has poorer outcomes compared with squamous cell carcinoma; however, treatment is identical irrespective of histologic sub-types. This study aimed to investigate the patterns and risk factors of recurrence following surgery alone for low-risk early-stage cervical adenocarcinoma.

METHODS

We retrospectively reviewed patients who underwent surgery alone for low-risk early-stage cervical adenocarcinoma between January 2001 and December 2018 in a single institution. Baseline clinicopathological characteristics were collected to identify the factors associated with recurrence-free survival.

RESULTS

A total of 252 patients met the inclusion criteria. Most patients underwent radical hysterectomy (218 patients, 86.5%) and had usual type endocervical adenocarcinoma (190 patients, 75.4%). The International Federation of Gynecology and Obstetrics 2018 stage was IA1 in 72 patients (27.4%), IA2 in 58 (22.1%), IB1 in 51 (19.4%), and IB2 in 71 patients (27.0%). With a median follow-up of 70.4 months (range 6.2-252.5 months), 5-year survival rates were as follows: locoregional recurrence-free survival, 93.0%; recurrence-free survival, 89.6%; overall survival, 94.7%. The recurrence patterns were local in nine patients (32.1%), regional in five patients (17.8%), distant in 10 patients (35.7%), local and distant in one patient (3.6%), regional and distant in two patients (7.2%), and locoregional and distant in one patient (3.6%). In multivariable analysis, negative human papillomavirus (HPV) status (HR 7.314; p<0.001) and deep cervical stromal invasion (HR 5.110; p=0.003) were associated with poor locoregional recurrence-free survival. Patients were stratified based on the number of risk factors and a statistically significant difference in locoregional recurrence-free survival was observed: 5-year survival rates of 99.0%, 84.2%, and 50.0% for patients with 0, 1, and 2 risk factors (0 vs 1, p=0.001; 1 vs 2, p=0.011).

CONCLUSION

Surgery alone for low-risk early-stage cervical adenocarcinoma was associated with favorable outcomes over a long follow-up period. Patients with the highest risk of recurrence were those with a negative HPV status and deep cervical stromal invasion. Additional management following surgery may be considered in patients with these risk factors.

Trends in radiotherapy administration in the management of hepatocellular carcinoma: Analysis of a Korean tertiary hospital registry of hepatocellular carcinoma patients diagnosed between 2005 and 2017

Purpose

To present the trends in radiotherapy for the management of hepatocellular carcinoma (HCC) at a single tertiary referral hospital in South Korea.

Materials and Methods

We retrospectively reviewed prospectively collected registry data of patients newly diagnosed with HCC between January 2005 and December 2017 at the Samsung Medical Center. Trends in radiotherapy, delivery techniques, tumor stage, and age were evaluated.

Results

During the study period, 9,132 patients were newly diagnosed with HCC at our institution. Of these, 2,445 patients (26.8%) received radiotherapy for all lesions, including extrahepatic metastases; 1,865 patients (20.4%) received radiotherapy for intrahepatic lesions alone, and 469 patients (5.1%) received radiotherapy as initial management. Although the proportion of patients receiving radiotherapy increased slightly over the study period (24.2% vs. 26.6%), the proportions of patients receiving radiotherapy for intrahepatic lesions (16.8% vs. 21.9%) and as initial management (0.1% vs. 12.5%) increased dramatically. The majority of patients treated between 2005 and 2008 received three-dimensional conformal radiotherapy (56.3%), whereas the majority of patients treated between 2018 and 2021 received proton beam therapy (43.6%). With the technical developments, the overall survival (OS) of patients who received radiotherapy as initial management increased significantly (5-year OS: from 5.4% to 30.1%), and the OS difference between patients who did and did not receive radiotherapy as initial management significantly decreased (ratio of restricted mean survival time: from 0.383 to 0.544).

Conclusion

This registry-based, retrospective study indicated an increasing trend in the utilization of radiotherapy, adoption of advanced radiotherapy techniques, and OS improvements in patients with HCC.

The Significance of Systemic Inflammation Markers in Intrahepatic Recurrence of Early-Stage Hepatocellular Carcinoma after Curative Treatment

Simple Summary

This retrospective study using the prospectively collected registry data of newly diagnosed, previously untreated hepatocellular carcinoma (HCC) evaluates the significance of systemic inflammatory markers (SIMs) to intrahepatic recurrence (IHR) after curative treatment. Out of 4076 patients who met the inclusion criteria, 52.6% experienced IHR. SIMs, including pre-treatment platelet-to-lymphocyte ratio (PLR), post-treatment changes of neutrophil-to-lymphocyte ratio PLR, and lymphocyte-to-monocyte ratio were significantly associated with the prognosis of early-stage HCC patients who received initial curative treatment. The prognostic significances of SIMs were consistent for IHR-free survival, early and late IHR, and overall survival.

Abstract

Systemic inflammatory markers (SIMs) are known to be associated with carcinogenesis and prognosis of hepatocellular carcinoma (HCC). We evaluated the significance of SIMs in intrahepatic recurrence (IHR) of early-stage HCC after curative treatment. This study was performed using prospectively collected registry data of newly diagnosed, previously untreated HCC between 2005 and 2017 at a single institution. Inclusion criteria were patients with Barcelona Clinic Liver Cancer stage 0 or A, who underwent curative treatment. Pre-treatment and post-treatment values of platelet, neutrophil, lymphocyte, monocyte, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and lymphocyte/monocyte ratio (LMR) were analyzed with previously well-known risk factors of HCC to identify factors associated with IHR-free survival (IHRFS), early IHR, and late IHR. Of 4076 patients, 2142 patients (52.6%) experienced IHR, with early IHR in 1018 patients (25.0%) and late IHR in 1124 patients (27.6%). Pre-treatment platelet count and PLR and post-treatment worsening of NLR, PLR, and LMR were independently associated with IHRFS. Pre-treatment platelet count and post-treatment worsening of NLR, PLR, and LMR were significantly related to both early and late IHR. Pre-treatment values and post-treatment changes in SIMs were significant factors of IHR in early-stage HCC, independent of previously well-known risk factors of HCC.

Predicting Tumor Budding Status in Cervical Cancer Using MRI Radiomics: Linking Imaging Biomarkers to Histologic Characteristics

BACKGROUND

Our previous study demonstrated that tumor budding (TB) status was associated with inferior overall survival in cervical cancer. The purpose of this study is to evaluate whether radiomic features can predict TB status in cervical cancer patients.

METHODS

Seventy-four patients with cervical cancer who underwent preoperative MRI and radical hysterectomy from 2011 to 2015 at our institution were enrolled. The patients were randomly allocated to the training dataset (n = 48) and test dataset (n = 26). Tumors were segmented on axial gadolinium-enhanced T1- and T2-weighted images. A total of 2074 radiomic features were extracted. Four machine learning classifiers, including logistic regression (LR), random forest (RF), support vector machine (SVM), and neural network (NN), were used. The trained models were validated on the test dataset.

RESULTS

Twenty radiomic features were selected; all were features from filtered-images and 85% were texture-related features. The area under the curve values and accuracy of the models by LR, RF, SVM and NN were 0.742 and 0.769, 0.782 and 0.731, 0.849 and 0.885, and 0.891 and 0.731, respectively, in the test dataset.

CONCLUSION

MRI-based radiomic features could predict TB status in patients with cervical cancer.

Robustness of magnetic resonance radiomic features to pixel size resampling and interpolation in patients with cervical cancer

Background

Radiomics is a promising field in oncology imaging. However, the implementation of radiomics clinically has been limited because its robustness remains unclear. Previous CT and PET studies suggested that radiomic features were sensitive to variations in pixel size and slice thickness of the images. The purpose of this study was to assess robustness of magnetic resonance (MR) radiomic features to pixel size resampling and interpolation in patients with cervical cancer.

Methods

This retrospective study included 254 patients with a pathological diagnosis of cervical cancer stages IB to IVA who received definitive chemoradiation at our institution between January 2006 and June 2020. Pretreatment MR scans were analyzed. Each region of cervical cancer was segmented on the axial gadolinium-enhanced T1- and T2-weighted images; 107 radiomic features were extracted. MR scans were interpolated and resampled using various slice thicknesses and pixel spaces. Intraclass correlation coefficients (ICCs) were calculated between the original images and images that underwent pixel size resampling (OP), interpolation (OI), or pixel size resampling and interpolation (OP+I) as well as among processed image sets with various pixel spaces (P), various slice thicknesses (I), and both (P + I).

Results

After feature standardization, ≥86.0% of features showed good robustness when compared between the original and processed images (OP, OI, and OP+I) and ≥ 88.8% of features showed good robustness when processed images were compared (P, I, and P + I). Although most first-order, shape, and texture features showed good robustness, GLSZM small-area emphasis-related features and NGTDM strength were sensitive to variations in pixel size and slice thickness.

Conclusion

Most MR radiomic features in patients with cervical cancer were robust after pixel size resampling and interpolation following the feature standardization process. The understanding regarding the robustness of individual features after pixel size resampling and interpolation could help future radiomics research.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-021-00388-5.

Magnetic resonance imaging features of tumor and lymph node to predict clinical outcome in node-positive cervical cancer: a retrospective analysis

Background

Current chemoradiation regimens for locally advanced cervical cancer are fairly uniform despite a profound diversity of treatment response and recurrence patterns. The wide range of treatment responses and prognoses to standardized concurrent chemoradiation highlights the need for a reliable tool to predict treatment outcomes. We investigated pretreatment magnetic resonance (MR) imaging features of primary tumor and involved lymph node for predicting clinical outcome in cervical cancer patients.

Methods

We included 93 node-positive cervical cancer patients treated with definitive chemoradiotherapy at our institution between 2006 and 2017. The median follow-up period was 38 months (range, 5–128). Primary tumor and involved lymph node were manually segmented on axial gadolinium-enhanced T1-weighted images as well as T2-weighted images and saved as 3-dimensional regions of interest (ROI). After the segmentation, imaging features related to histogram, shape, and texture were extracted from each ROI. Using these features, random survival forest (RSF) models were built to predict local control (LC), regional control (RC), distant metastasis-free survival (DMFS), and overall survival (OS) in the training dataset (n = 62). The generated models were then tested in the validation dataset (n = 31).

Results

For predicting LC, models generated from primary tumor imaging features showed better predictive performance (C-index, 0.72) than those from lymph node features (C-index, 0.62). In contrast, models from lymph nodes showed superior performance for predicting RC, DMFS, and OS compared to models of the primary tumor. According to the 3-year time-dependent receiver operating characteristic analysis of LC, RC, DMFS, and OS prediction, the respective area under the curve values for the predicted risk of the models generated from the training dataset were 0.634, 0.796, 0.733, and 0.749 in the validation dataset.

Conclusions

Our results suggest that tumor and lymph node imaging features may play complementary roles for predicting clinical outcomes in node-positive cervical cancer.

Simultaneous integrated boost intensity-modulated radiotherapy versus 3-dimensional conformal radiotherapy in preoperative concurrent chemoradiotherapy for locally advanced rectal cancer

Purpose

To evaluate the feasibility of simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) for preoperative concurrent chemoradiotherapy (PCRT) in locally advanced rectal cancer (LARC), by comparing with 3-dimensional conformal radiotherapy (3D-CRT).

Materials and Methods

Patients who were treated with PCRT for LARC from 2015 January to 2016 December were retrospectively enrolled. Total doses of 45 Gy to 50.4 Gy with 3D-CRT or SIB-IMRT were administered concomitantly with 5-fluorouracil plus leucovorin or capecitabine. Surgery was performed 8 weeks after PCRT. Between PCRT and surgery, one cycle of additional chemotherapy was administered. Pathologic tumor responses were compared between SIB-IMRT and 3D-CRT groups. Acute gastrointestinal, genitourinary, hematologic, and skin toxicities were compared between the two groups based on the RTOG toxicity criteria.

Results

SIB-IMRT was used in 53 patients, and 3D-CRT in 41 patients. After PCRT, no significant differences were noted in tumor responses, pathologic complete response (9% vs. 7%; p = 1.000), pathologic tumor regression Grade 3 or higher (85% vs. 71%; p = 0.096), and R0 resection (87% vs. 85%; p = 0.843). Grade 2 genitourinary toxicities were significantly lesser in the SIB-IMRT group (8% vs. 24%; p = 0.023), but gastrointestinal toxicities were not different across the two groups.

Conclusion

SIB-IMRT showed lower GU toxicity and similar tumor responses when compared with 3D-CRT in PCRT for LARC.

The response of thrombosis in the portal vein or hepatic vein in hepatocellular carcinoma to radiation therapy

Purpose

The purpose of current study is to evaluate the response of the patients with portal vein thrombosis (PVT) or hepatic vein thrombosis (HVT) in hepatocellular carcinoma (HCC) treated with three-dimensional conformal radiation therapy (3D-CRT). In addition, survival of patients and potential prognostic factors of the survival was evaluated.

Materials and Methods

Forty-seven patients with PVT or HVT in HCC, referred to our department for radiotherapy, were retrospectively reviewed. For 3D-CRT plans, a gross tumor volume (GTV) was defined as a hypodense filling defect area in the portal vein (PV) or hepatic vein (HV). Survival of patients, and response to radiation therapy (RT) were analyzed. Potential prognostic factors for survival and response to RT were evaluated.

Results

The median survival time of 47 patients was 8 months, with 1-year survival rate of 15% and response rate of 40%. Changes in Child-Pugh score, response to RT, Eastern cooperative oncology group performance status (ECOG PS), hepatitis C antibody (HCVAb) positivity, and additional post RT treatment were statistically significant prognostic factors for survival in univariate analysis (p = 0.000, p = 0.018, p = 0.000, p = 0.013, and p = 0.047, respectively). Of these factors, changes in Child-Pugh score, and response to RT were significant for patients’ prognosis in multivariate analysis (p = 0.001 and p = 0.035, respectively).

Conclusion

RT could constitute a reasonable treatment option for patients with PVT or HVT in HCC with acceptable toxicity. Changes in Child-Pugh score, and response to RT were statistically significant factors of survival of patients.

Establishing the Origin of Elevated Uranium Concentrations in Groundwater near the Central Ogcheon Metamorphic Belt, Korea

We examined the origin of the U-enriched groundwater in Daejeon, near the Ogcheon U zone in Korea. For this study, groundwater ionic species and C, S, and Sr isotopic compositions were analyzed. The U-enriched groundwater occurred only in the Daejeon granite region, while all the groundwater in the Ogcheon Supergroup showed very low U concentrations. In the granite region, the pedospheric or atmospheric origin of dissolved C and S means that the aquifer has been well connected to the oxidized surface environment. The Sr/Sr ratios indicated a lithospheric origin of Sr. Groundwater isotopic compositions in the Ogcheon belt varied greatly, indicating their complex sources. In this region, dissolved C originated from graphite-rich slate and limestone. The broad range of δS suggested that the composite sources included atmospheric SO for most groundwater, lithogenic SO for mine drainage and quarry water, and anthropogenic SO for polluted groundwater. This study indicates that the U-enriched groundwater is not related to the present U ores in the Ogcheon belt but is genetically associated with the granite body itself. The varying but considerable U contents within the granite body can be present as isolated groups. We infer that locally high U contents in the Daejeon granite might inherently be due to assimilation of the Ogcheon U-mineralized zone into granitic melt during the Mesozoic; however, the pH and Eh conditions except aquifer geology were very important factors in developing highly enriched U groundwater in the Daejeon granite region. Thermodynamic modeling highlights the importance of dissolved Ca and (bi-)carbonate in U geochemistry.

Duct-to-duct biliary reconstructions and complications in 100 living donor liver transplantations

OBJECTIVE

We evaluated the risk factors for biliary complications and surgical procedures for duct-to-duct reconstructions in adult living donor liver transplantation (LDLT).

PATIENTS AND METHODS

From February 2005 to March 2008, we performed 100 cases of adult LDLT with duct-to-duct biliary reconstruction, using 64 right lobe grafts, 33 left lobe grafts, and 3 right lateral grafts. We employed 4 types of duct-to-duct procedures: all interrupted 6-0 Prolene suture (group 1, n = 9); continuous posterior and interrupted anterior wall 6-0 Prolene suture (group 2, n = 49); all continuous 7-0 Prolene suture (group 3, n = 26); and all continuous 7-0 Prolene suture with external stent (group 4, n = 16). Biliary complications were defined as an anastomosis stricture or a leakage.

RESULTS

Thirty-four patients experienced biliary complications during the follow-up period (median, 27 months). The incidence of stricture was 27% and that of leakage, 8%. There were no perioperative, intraoperative, or anatomic risk factors for biliary complications, except the type of duct-to-duct procedure. Group 1 and 2 patients showed higher incidences of biliary strictures than groups 3 and 4 (43.1% vs 4.7%; P = .00). Group 3 patients experienced a higher incidence of bile leakage than the other groups (23.1% vs 2.7%; P = .004).

CONCLUSIONS

The type of biliary reconstruction is a factor affecting biliary complications following duct-to-duct anastomosis in LDLT. Duct-to-duct biliary anastomosis with 7-0 monofilament suture and a small external stent is a feasible procedure in LDLT that significantly reduces the incidence of biliary complications.