Efficacy of Bowel Regimen in Decreasing Postoperative Constipation in Bariatric Surgery Patients.

PURPOSE: Postoperative constipation after bariatric surgery is a common complaint, decreasing patient quality of life. No literature exists examining the efficacy of a preoperative bowel regimen in reducing postoperative constipation in this cohort. This study aims explore the efficacy of a well-established bowel regimen, polyethylene glycol (PEG), in reducing constipation frequency and severity after bariatric surgery. METHODS: This was a retrospective study of adult patients undergoing primary and revisional bariatric procedures. The use of PEG bowel prep for bariatric patients was introduced as an institutional quality improvement measure. Patients during the first 3 months after PEG implementation were surveyed for postoperative constipation. For the year after implementation, patients were followed for 30-day emergency room visits or hospitalization secondary to constipation. This cohort was compared to historical controls from the previous year. Student t-tests were used for statistical analysis. RESULTS: During the 3-month exploratory phase, 28/49 (57.14%) patients fully completed the bowel regimen. In total, 0/56 (0%) patients reported preoperative constipation, and 5/28 (17.9%) patients reported constipation at the 3-week follow-up. In the 1 year post-implementation cohort, 2/234 (0.85%) patients had constipation-related occurrences at 30-day follow-up, compared to 8/219 patients (3.65%) in the historical cohort (p = 0.04). CONCLUSIONS: The implementation of a PEG-based bowel regimen did not eliminate self-reported constipation. However, there were significant differences in rates of constipation-related ED visits and hospital readmissions, suggesting that the bowel regimen decreases rates of severe constipation. Finally, patient compliance was limited. Future work should aim towards increasing compliance.

Incidental Bleeding Gastrointestinal Stromal Tumor Identified on 99m Tc-RBC Scintigraphy.

ABSTRACT: Various pathologies could lead to occult gastrointestinal (GI) bleeding. Here we report the case of a 73-year-old woman who presented with hematochezia and syncope, and was found to have a large bleeding GI stromal tumor incidentally from 99m Tc-RBC scintigraphy. This study was done after negative workup with CT angiography, colonoscopy, and capsule endoscopy for the source of GI bleeding. Final pathology confirmed the mass being a low-grade GI stromal tumor after exploratory laparotomy.

Effect of gender discordance on surgical outcomes in predominantly female patient surgeries in NYS.

BACKGROUND: Preliminary evidence demonstrates female surgeons have improved post-operative outcomes compared to male colleagues despite underrepresentation in surgery. This study explores the effect of patient-surgeon gender discordance on outcomes in three specialties with high female patient populations: bariatric, foregut, colorectal. METHODS: This is a retrospective study using the New York State (NYS) SPARCS database and first study evaluating outcomes based on surgeon/patient concordance in NYS. Bariatric, foregut, and colorectal surgery cases from 2013 to 2017 were identified. RESULTS: Bariatric: female patients (FP) with CC had lower 30-day readmissions but higher complications compared with DC. Male patients (MP) with CC trended towards higher 30-day readmissions but lower complications compared with DC. FP received significantly better influence from CC in 30-day readmission, but disadvantages in complications. There was no significant difference in LOS or ED visits between CC and DC groups for either FP or MP. Foregut: FP with CC had lower LOS, 30-day readmissions, and 30-day ED visits compared with DC. MP showed opposite trends between CC and DC, although non-significant. The benefit from concordance was pronounced in FP compared to MP in LOS, 30-day readmissions, and 30-day ED visit. Concordance vs discordance did not significantly affect complications within either FP or MP group. Colorectal: the difference between CC and DC was not significant within FP or MP groups in any outcomes. When comparing the difference of 30-day readmissions in CC vs DC between FP and MP, there is a significant difference. CONCLUSION(S): Overall, our results show DC between patient and surgeon has significant effect on patient outcomes. A negative effect is seen for female patients in certain specialties, most pronounced in foregut surgery. This emphasizes need for surgeons to be conscious of care provided to opposite gender patients and underscores increasing female surgeons in high FP fields.

The impact of interval cholecystectomy timing after percutaneous transhepatic cholecystostomy on post-operative adverse outcomes.

OBJECTIVE: This study aims to explore how timing of interval of cholecystectomy (IC) after percutaneous transhepatic cholecystostomy tube (PTC) placement impacts post-operative outcomes. METHODS: A retrospective database analysis of New York State SPARCs database of IC between 2005 and 2015. The timing for IC ranged between > 1 week and < 2 years. Patients undergoing this procedure were further divided into quartiles using 4-time intervals; 1-5 weeks (Q1), 5-8 weeks (Q2), 8-12 weeks(Q3), and > 12 weeks(Q4). The study's primary outcome was hospital length of stay (LOS). Secondary outcomes included discharge status, 30-day readmission, 30-day ED visit, and 90-day reoperation, surgery type, complication, and bile duct injury. Multivariable regression models were used to compare patients across the four-time intervals after adjusting for confounding factors. RESULTS: A total of 1038 patients with a history of PTC followed by IC between > 1 week and < 2 years were included in the final analysis. The median time to IC was 7.7 weeks. Q2 and Q3 both had a significantly higher median LOS of 3 days versus Q1 and Q4 at median of 5 days (p < 0.0001). Patients from racial and ethnic minorities (e.g., African Americans and Hispanics) were more likely to get their IC after 12 weeks (p < 0.05). Further, Black patients had a significantly higher median LOS than White, non-Hispanic patients (8 days vs 4 days, p < 0.0001) and were more likely to have open procedure. Multivariable regression analysis identified shorter LOS during Q2 (Ratio, 0.76, 95%, 0.67-0.87, p < 0.0001), and Q3 (Ratio 0.75, 95% CI, 065-0.86, p < 0.0001) compared to those who got their IC in Q4. Similar findings exist when comparing Q2 and Q3 to those receiving treatment during Q1. CONCLUSION: A time interval of 5-12 weeks between PTC and IC was associated with a decreased LOS. This study also suggests the persistence of racial disparities among these patients.

Postoperative outcomes for sleeve gastrectomy patients with positive pH-defined GERD.

BACKGROUND: Gastroesophageal reflux disease (GERD) is a possible side effect of sleeve gastrectomy (SG). However, procedure selection for patients with GERD and risk factors for morbidity after bypass surgeries is complex. For patients with a preoperative GERD diagnosis, literature related to worsening postoperative symptoms is discordant. OBJECTIVE: This study evaluated the effects of SG on patients with pre-operative GERD confirmed through pH testing. SETTING: University Hospital, United States. METHODS: This was a single-center case-series. SG patients with preoperative pH testing were compared based on DeMeester scoring. Preoperative demographics, endoscopy results, need for conversion surgery, and changes in gastrointestinal quality of life (GIQLI) scores were compared. Two-sample independent t-tests assuming unequal variances were used for statistical analysis. RESULTS: Twenty SG patients had preoperative pH testing. Nine patients were GERD positive; median DeMeester score 26.7 (22.1-31.15). Eleven patients were GERD negative, with a median DeMeester score of 9.0 (4.5-13.1). The two groups had similar median BMI, preoperative endoscopic findings and use of GERD medications. Concurrent hiatal hernia repair was performed in 22% of GERD positive vs. 36% of GERD negative patients, (p = 0.512). Two patients in the GERD positive cohort required conversion to gastric bypass (22%), while none in the GERD negative cohort did. No significant postoperative differences were noted in GIQLI, heartburn, or regurgitation symptoms. CONCLUSION: Objective pH testing may allow the differentiation of patients who would be higher risk for need for conversion to gastric bypass. For patients with mild symptoms, but negative pH testing, SG may represent a durable option.

Voxel-based dosimetry predicting treatment response and related toxicity in HCC patients treated with resin-based Y90 radioembolization: a prospective, single-arm study.

BACKGROUND: There is an increasing body of evidence indicating Y90 dose thresholds for tumor response and treatment-related toxicity. These thresholds are poorly studied in resin Y90, particularly in hepatocellular carcinoma (HCC). PURPOSE: To evaluate the efficacy of prospective voxel-based dosimetry for predicting treatment response and adverse events (AEs) in patients with HCC undergoing resin-based Y90 radioembolization. MATERIALS AND METHODS: This correlative study was based on a prospective single-arm clinical trial (NCT04172714), which evaluated the efficacy of low/scout (555 MBq) activity of resin-based Y90 for treatment planning. Partition model was used with goal of tumor dose (TD) > 200 Gy and non-tumoral liver dose (NTLD) < 70 Gy for non-segmental therapies. Single compartment dose of 200 Gy was used for segmentectomies. Prescribed Y90 activity minus scout activity was administered for therapeutic Y90 followed by Y90-PET/CT. Sureplan® (MIM Software, Cleveland, OH) was used for dosimetry analysis. Treatment response was evaluated at 3 and 6 months. Receiver operating characteristic curve determined TD response threshold for objective response (OR) and complete response (CR) as well as non-tumor liver dose (NTLD) threshold that predicted AEs. RESULTS: N = 30 patients were treated with 33 tumors (19 segmental and 14 non-segmental). One patient died before the first imaging, and clinical follow-up was excluded from this analysis. Overall, 26 (81%) of the tumors had an OR and 23 (72%) had a CR. A mean TD of 253 Gy predicted an OR with 92% sensitivity and 83% specificity (area under the curve (AUC = 0.929, p < 0.001). A mean TD of 337 Gy predicted a CR with 83% sensitivity and 89% specificity (AUC = 0.845, p < 0.001). A mean NTLD of 81 and 87 Gy predicted grade 3 AEs with 100% sensitivity and 100% specificity in the non-segmental cohort at 3- and 6-month post Y90, respectively. CONCLUSION: In patients with HCC undergoing resin-based Y90, there are dose response and dose toxicity thresholds directly affecting outcomes. CLINICAL TRIAL NUMBER: NCT04172714.

Accuracy and Safety of Scout Dose Resin Yttrium-90 Microspheres for Radioembolization Therapy Treatment Planning: A Prospective Single-Arm Clinical Trial.

PURPOSE: To compare the accuracy and safety of 0.56 GBq resin yttrium-90 (90Y) (scout90Y) microspheres with those of technetium-99m macroaggregated albumin (MAA) in predicting the therapeutic 90Y (Rx90Y) dose for patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This prospective single-arm clinical trial (Clinicaltrials.gov: NCT04172714) recruited patients with HCC. Patients underwent same-day mapping with MAA and scout90Y. Rx90Y activity was administered 3 days after mapping. Using paired t test and Pearson correlation, the tumor-to-normal ratio (TNR), lung shunt fraction (LSF), predicted mean tumor dose (TD), and nontumoral liver dose (NTLD) by MAA and scout90Y were compared with those by Rx90Y. Bland-Altman plots compared the level of agreement between the TNR and LSF of scout90Y and MAA with that of Rx90Y. The safety of scout90Y was evaluated by examining the discrepancy in extrahepatic activity between MAA and scout90Y. RESULTS: Thirty patients were treated using 19 segmental and 14 nonsegmental (ie, 2 contiguous segments or nonsegmental) therapies. MAA had weak LSF, moderate TNR, and moderate TD linear correlation with Rx90Y. Scout90Y had a moderate LSF, strong TNR, strong TD, and very strong NTLD in correlation with those of Rx90Y. Furthermore, the TNR and LSF of scout90Y had a stronger agreement with those of Rx90Y than with those of MAA. In the nonsegmental subgroup, MAA had no significant correlation with the TD and NTLD of Rx90Y, whereas scout90Y had a very strong correlation with both of these factors. In the segmental subgroup, both MAA and scout90Y had a strong linear correlation with the TD and NTLD of Rx90Y. CONCLUSIONS: Compared with MAA, scout90Y is a more accurate surrogate for Rx90Y biodistribution for nonsegmental therapies.

Study Protocol: Efficacy and Safety of Radioembolization (REM) as an Early Modality (EM) Therapy for Metastatic Breast Cancer (BR) to the Liver with Y90 (REMEMBR Y90).

PURPOSE: The primary objective of the REMEMBR Y90 study is to evaluate the efficacy of Yttrium-90 (Y90) radioembolization in patients with breast cancer metastases to the liver as a 2nd or 3rd line treatment option with systemic therapy by assessing liver-specific and overall progression-free survival. Secondary objectives include quality of life, overall survival benefit, and toxicity in relation to patients' tumor biology. MATERIALS AND METHODS: This trial is a multi-center, prospective, Phase 2, open-label, IRB-approved, randomized control trial in the final phases of activation. Eligible patients include those over 18 years of age with metastatic breast cancer to the liver with liver-only or liver-dominant disease, and history of tumor progression on 1-2 lines of chemotherapy. 60 patients will be randomized to radioembolization with chemotherapy versus chemotherapy alone. Permissible regimens include capecitabine, eribulin, vinorelbine, and gemcitabine within 2 weeks of enrollment for every patient. Patients receiving radioembolization will receive lobar or segmental treatment within 1-6 weeks of enrollment depending on their lesion. After final radioembolization, patients will receive clinical and imaging follow-up every 12-16 weeks for two years, including contrast-enhanced computed tomography or magnetic resonance imaging of the abdomen and whole-body positron emission tomography/computed tomography. DISCUSSION: This study seeks to elucidate the clinical benefit and toxicity of Y90 in patients with metastatic breast cancer to the liver who are receiving minimal chemotherapy. Given previous data, it is anticipated that the use of Y90 and chemotherapy earlier in the metastatic disease course would improve survival outcomes and reduce toxicity. LEVEL OF EVIDENCE: Level 1b, Randomized Controlled Trial. TRIAL REGISTRATION NUMBER: NCT05315687 on clinicaltrials.gov.

ACR-ACNM-ASTRO-SNMMI Practice Parameter for Lutetium-177 (Lu-177) DOTATATE Therapy.

OBJECTIVES: This practice parameter (PP) for Lutetium-177 (Lu-177) DOTATATE peptide receptor radionuclide therapy (PRRT) aims to guide authorized users in selection of appropriate adult candidates with gastroeneropancreatic neuroendocrine tumors (GEP-NETs) from foregut, midgut, and hindgut. The essential selection criteria include somatostatin receptor-positive GEP-NETs, which are usually inoperable and progressed despite standard therapy. Lu-177 DOTATATE is a radiopharmaceutical with high avidity for somatostatin receptors that are overexpressed by these tumors. This document ensures safe handling of Lu-177 DOTATATE by the authorized users and safe management of affected patients. METHODS: The document was developed according to the systematic process developed by the American College of Radiology (ACR) and described on the ACR Web site (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards). The PP development was led by 2 ACR Committees on Practice Parameters (Nuclear Medicine and Molecular Imaging and Radiation Oncology) collaboratively with the American College of Nuclear Medicine, American Society of Radiation Oncology, and Society of Nuclear Medicine and Molecular Imaging. RESULTS: The Lu-177 DOTATATE PP reviewed pharmacology, indications, adverse effects, personnel qualifications, and required clinical evaluation before starting the treatment, as well as the recommended posttherapy monitoring, quality assurance, documentation, and appropriate radiation safety instructions provided in written form and explained to the patients. CONCLUSIONS: Lu-177 DOTATATE is available for therapy of inoperable and/or advanced GEP-NETs when conventional therapy had failed. It can reduce tumor size, improve symptoms, and increase the progression free survival. The PP document provides clinical guidance for authorized users to assure an appropriate, consistent, and safe practice of Lu-177 DOTATATE.

ACR-ACNM-ASTRO-SNMMI Practice Parameter for Lutetium-177 (Lu-177) DOTATATE Therapy.

OBJECTIVES: This practice parameter (PP) for Lutetium-177 (Lu-177) DOTATATE peptide receptor radionuclide therapy (PRRT) aims to guide authorized users in selection of appropriate adult candidates with gastroeneropancreatic neuroendocrine tumors (GEP-NETs) from foregut, midgut, and hindgut. The essential selection criteria include somatostatin receptor-positive GEP-NETs, which are usually inoperable and progressed despite standard therapy. Lu-177 DOTATATE is a radiopharmaceutical with high avidity for somatostatin receptors that are overexpressed by these tumors. This document ensures safe handling of Lu-177 DOTATATE by the authorized users and safe management of affected patients. METHODS: The document was developed according to the systematic process developed by the American College of Radiology (ACR) and described on the ACR Web site (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards). The PP development was led by 2 ACR Committees on Practice Parameters (Nuclear Medicine and Molecular Imaging and Radiation Oncology) collaboratively with the American College of Nuclear Medicine, American Society of Radiation Oncology, and Society of Nuclear Medicine and Molecular Imaging. RESULTS: The Lu-177 DOTATATE PP reviewed pharmacology, indications, adverse effects, personnel qualifications, and required clinical evaluation before starting the treatment, as well as the recommended posttherapy monitoring, quality assurance, documentation, and appropriate radiation safety instructions provided in written form and explained to the patients. CONCLUSIONS: Lu-177 DOTATATE is available for therapy of inoperable and/or advanced GEP-NETs when conventional therapy had failed. It can reduce tumor size, improve symptoms, and increase the progression free survival. The PP document provides clinical guidance for authorized users to assure an appropriate, consistent, and safe practice of Lu-177 DOTATATE.

82Rubidium chloride positron emission tomography discrimination of recurrent intracranial malignancy from radiation necrosis.

BACKGROUND: Accurate identification and discrimination of post treatment changes from recurrent disease remains a challenge for patients with intracranial malignancies despite advances in molecular and magnetic resonance imaging. We have explored the ability of readily available Rubidium-82 chloride (82RbCl) positron emission tomography (PET) to identify and distinguish progressive intracranial disease from radiation necrosis in patients previously treated with radiation therapy. METHODS: Six patients with a total of 9 lesions of either primary (N.=3) or metastatic (N.=6) intracranial malignancies previously treated with stereotactic radiation surgery (SRS) and persistent contrast enhancement on MRI underwent brain 82RbCl PET imaging. Two patients with arteriovenous malformations previously treated with SRS, also had brain 82RbCl PET imaging for a total of 11 lesions studied. Histological confirmation via stereotactic biopsy/excisional resection was obtained for 9 lesions with the remaining 2 classified as either recurrent tumor or radiation necrosis based on subsequent MRI examinations. 82RbCl PET time activity curve analysis was performed which comprised lesion SUVmax, contralateral normal brain SUVmax, and tumor to background ratios (TBmax). RESULTS: 82RbCl demonstrates uptake greater than normal brain parenchyma in all lesions studied. Time activity curves demonstrated progressive uptake of 82RbCl in all lesions without evidence of washout. While recurrent disease demonstrated a greater mean SUVmax compared to radiation necrosis, no statistically significant difference between lesion SUVmax nor TBmax was found (P>0.05). CONCLUSIONS: 82RbCl PET produces high-contrast uptake of both recurrent disease and radiation necrosis compared to normal brain. However, no statistically significant difference was found between recurrent tumor and radiation necrosis.

Role of Resin Microsphere Y90 Dosimetry in Predicting Objective Tumor Response, Survival and Treatment Related Toxicity in Surgically Unresectable Colorectal Liver Metastasis: A Retrospective Single Institution Study.

PURPOSE: To Evaluate the correlation between tumor dosimetric parameters with objective tumor response (OR) and overall survival (OS) in patients with surgically unresectable colorectal liver metastasis (CRLM) undergoing resin-based Ytrrium-90 selective internal radiation therapy (Y90 SIRT). MATERIALS AND METHODS: 45 consecutive patients with CRLM underwent resin-based Y90 SIRT in one or both hepatic lobes (66 treated lobes total). Dose volume histograms were created with MIM Sureplan® v.6.9 using post-treatment SPECT/CT. Dosimetry analyses were based on the cumulative volume of the five largest tumors in each treatment session and non-tumoral liver (NTL) dose. Receiver operating characteristic (ROC) curve was used to evaluate tumor dosimetric factors in predicting OR by Response Evaluation Criteria for Solid Tumors at 3 months post-Y90. Additionally, ROC curve was used to evaluate non-tumoral liver dose as a predictor of grade ≥ 3 liver toxicity and radioembolization induced liver disease (REILD) 3 months post Y90. To minimize for potential confounding demographic and clinical factors, univariate and multivariate analysis of survival with mean tumor dose as one of the factors were also performed. Kaplan-Meier estimation was used for OS analysis from initial Y90 SIRT. RESULTS: 26 out of 45 patients had OR with a median OS of 17.2 months versus 6.8 months for patients without OR (p < 0.001). Mean tumor dose (TD) of the five largest tumors was the strongest predictor of OR with an area under the curve of 0.73 (p < 0.001). Minimum TD, and TD to 30%, 50%, and 70% of tumor volume also predicted OR (p's < 0.05). Mean TD ≥ 100 Gy predicted a significantly prolonged median OS of 19 vs. 11 months for those receiving TD < 100 Gy (p = 0.016). On univariate analysis, mean TD < 100 Gy, presence of any genomic mutation, presence of MAPK pathway mutation, bilobar hepatic metastases and diffuse metastatic disease (>10 lesions per liver lobe) were found to be predictors of shorter median OS. On multivariate analysis, mean TD < 100 Gy, presence of any genomic mutation, and diffuse hepatic metastatic disease were found to be independent predictors of shorter OS. Overall, six (13.3%) patients developed grade ≥ 3 liver toxicity post Y90 of whom two (4.4%) patients developed REILD. No dose threshold predicting grade ≥ 3 liver toxicity or REILD was identified. CONCLUSIONS: Mean TD ≥ 100 Gy in patients with unresectable CRLM undergoing resin-based Y90 SIRT predicts OR and prolonged OS.

Same day yttrium-90 radioembolization with single photon emission computed tomography/computed tomography: An opportunity to improve care during the COVID-19 pandemic and beyond.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has made it more challenging for patients to undergo yttrium-90 (Y-90) radioembolization (RE). Same day Y-90 RE provides an opportunity to minimize logistical challenges and infection risk associated with COVID-19, thus improving patient access. AIM: To describe the use of same day Y-90 RE with routine single photon emission computed tomography/computed tomography (SPECT/CT) in order to optimize therapy. METHODS: All patients were selected for Y-90 RE through a multidisciplinary tumor board, and were screened and tested for COVID-19 infection per institutional protocol. A same day procedure was developed, consisting of angiography, imaging, and Y-90 resin particle delivery. Routine SPECT/CT after technetium-99m macroaggregated albumin (Tc-99m MAA) administration was performed for assessment of arterial supply, personalized dosimetry, and extrahepatic activity. Post-treatment Y-90 bremsstrahlung SPECT/CT was performed for confirmation of particle delivery, by utilization of energy windowing to limit signal from previously administered Tc-99m MAA particles. RESULTS: A total of 14 patients underwent same day Y-90 RE between March and June 2020. Mean lung shunt fraction was 6.13% (range 3.5%-13.1%). Y-90 RE was performed for a single lesion in 7 patients, while the remaining 7 patients had treatment of multifocal lesions. The largest lesion measured 8.3 cm. All patients tolerated the procedure well and were discharged the same day. CONCLUSION: Same day Y-90 RE with resin-based microspheres is feasible, and provides an opportunity to mitigate infection risk and logistical challenges associated with the COVID-19 pandemic and beyond. We recommend consideration of SPECT/CT, especially among patients with complex malignancies, for the potential to improve outcomes and eligibility of patients to undergo same day Y-90 RE.

Constellation of Von Hippel-Lindau Disease-Related Findings on a 68Ga-DOTATATE PET/CT.

ABSTRACT: Von Hippel-Lindau (VHL) is a rare predominantly hereditary syndrome characterized by multiple benign and malignant tumors that can affect different organ systems. We present representative images of a 68Ga-DOTATATE PET/CT in a patient with confirmed VHL gene mutation, which demonstrates a constellation of findings commonly seen in these patients in one single imaging modality.

Determination of tumour dose response threshold and implication on survival in patients with HCC treated with Y90 radiation segmentectomy: a simple semi-quantitative analysis.

PURPOSE: To evaluate the relationship between Yttrium-90 (Y90) tumour dose and response rate in patients with hepatocellular carcinoma (HCC) who undergo Y90 radiation segmentectomy (Y90-RS) and to determine implication on overall survival (OS). MATERIALS AND METHODS: Post Y90-RS Bremsstrahlung single-photon emission computed tomography/CT of 105 HCC patients with 110 treatments performed with glass microspheres was retrospectively analysed. The dose-volume histogram of the targeted tumour was determined with commercially available dosimetry software. Tumour response at 3 months was evaluated using modified Response Evaluation Criteria in Solid Tumours. Tumour dose thresholds associated with the objective response with 80% specificity were then used to evaluate implication on OS using Kaplan-Meier estimation and log-rank analysis. RESULTS: Tumour dose thresholds to predict objective response with 80% specificity were the following: maximum tumour dose (748 Gy), mean tumour dose (568 Gy), minimum tumour dose of 30% tumour volume (608 Gy), minimum tumour dose of 50% tumour volume (565 Gy), minimum tumour dose of 70% tumour volume (464 Gy) and minimum tumour dose of 100% tumour volume (213 Gy). These parameters all significantly predicted tumour response with areas under the ROC curve of >0.6. Mean tumour dose of ≥250 Gy predicted median OS of 43.67 vs. 17.87 months for others (P = 0.026). Minimum dose ≥180 Gy to 100% of tumour volume predicted median OS of 44.93 vs. 35.87 months for others (P = 0.043). CONCLUSION: In patients with HCC undergoing Y90-RS, mean tumour dose ≥250 Gy and minimum tumour dose of ≥180 Gy to 100% of tumour volume are both significantly correlated with higher objective tumour response and prolonged survival.

Determination of Tumor Dose Response Thresholds in Patients with Chemorefractory Intrahepatic Cholangiocarcinoma Treated with Resin and Glass-based Y90 Radioembolization.

PURPOSE: To compare the efficacies of glass and resin-based Yttrium-90 microspheres by comparing absorbed tumor dose (TD) with both tumor response (TR) and overall survival (OS) in patients with chemorefractory intrahepatic cholangiocarcinoma (ICC). METHODS: Post-Y90 treatment bremsstrahlung SPECT/CT of 38 consecutive patients receiving 45 treatments (21 resin microspheres, 24 glass microspheres) were analyzed retrospectively. MIM software v6.9.4 (MIM Software Inc, Cleveland, OH) was used to calculate targeted tumors' dose volume histogram. Modified Response Evaluation Criteria in Solid Tumors was used to evaluate tumor response 3 months post-treatment. Kaplan Meier estimation was used for survival analysis. T-test was used to compare the devices on various dosimetric parameters. RESULTS: Thresholds for TD to predict TR with ≥ 80% specificity were as follows: mean TD (Resin: 78.9 Gy; Glass: 254.7 Gy), maximum TD (Resin: 162.9 Gy; Glass: 591 Gy), minimum TD (Resin: 53.7 Gy; Glass: 149.1 Gy). Microsphere type had no effect on survival from first Y90 (Resin: 11.2 mo; Glass 10.9 mo [p = 0.548]). In patients receiving resin microspheres, mean TD ≥ 75 Gy or maximum TD ≥ 150 Gy was associated with median OS of 20.2 mo compared to 6.5 mo for those receiving less (p = 0.001, 0.002, respectively). For patients treated with glass microspheres, those receiving a mean TD ≥ 150 Gy had a median OS of 14.6 mo vs. 2.6 mo for those receiving less (p = 0.031). CONCLUSION: TD thresholds predictive of TR and OS differ significantly between glass and resin microspheres. However, microsphere type has no impact on survival in patients with chemorefractory ICC. LEVEL OF EVIDENCE: Level 3, Retrospective Study.

Tumor-to-Normal Ratio Relationship between Planning Technetium-99 Macroaggregated Albumin and Posttherapy Yttrium-90 Bremsstrahlung SPECT/CT.

PURPOSE: To quantify the relationship of the tumor-to-normal ratio (TNR) attained from the technetium-99m macroaggregated albumin (MAA) and posttreatment yttrium-90 bremsstrahlung (Y90-Brem) single-photon emission computerized tomography (SPECT)/computer tomography (CT) studies in patients with hepatocellular carcinoma (HCC) treated with glass microspheres. MATERIALS AND METHODS: Retrospectively, a total of 190 consecutive patients with HCC who underwent 204 MAA and Y90-Brem SPECT/CT for glass microsphere Y90 radiation segmentectomy (Y90-RS) or lobar treatment (Y90-RLT) between 2013 and 2018 were included. Semi-automated regions-of-interests were drawn around the targeted tumor and nontumoral liver tissue on the SPECT/CT studies. TNR values from MAA and Y90-Brem SPECT/CT were compared using paired t-tests, Pearson correlation, and median with interquartile ranges (IQR). RESULTS: The mean TNR for MAA and Y90-Brem SPECT/CT was 2.96 ± 1.86 (median, 2.64; IQR, 2.50) and 2.29 ± 1.10 (median, 2.06; IQR, 1.05), respectively (P < .0001). The mean Y90-RLT TNR was 2.88 ± 1.67 (median, 2.59; IQR, 0.83) and 2.17 ± 0.89 (median, 1.98; IQR, 0.81) for MAA and Y90-Brem SPECT/CT, respectively (P < .0001). The mean Y90-RS TNR was 3.02 ± 2.01 (median, 2.87; IQR, 3.01) and 2.39 ± 1.25 (median, 2.11; IQR, 1.28) for MAA and Y90-Brem SPECT/CT, respectively (P = .0003). TNR attained from MAA and Y90 SPECT/CT studies showed a moderate correlation in a positive linear fashion for the overall (r = 0.54; P < .001), Y90-RLT (r = 0.66, P < .001), and Y90-RS cohorts (r = 0.48, P < .001). CONCLUSIONS: The TNR attained from Y90-Brem SPECT/CT is often underestimated, positively correlated, and less variable than that attained from MAA SPECT/CT.

Optimal Management of the Hyperkinetic Gallbladder: A Comparison of Outcomes Between Operative and Nonoperative Approaches.

BACKGROUND: A hyperkinetic gallbladder is defined as a hepatobiliary iminodiacetic acid (HIDA) scan ejection fraction (EF) of >80%. This condition is poorly described, and there is no current consensus on optimal management. The intent of this study was to determine if cholecystectomy improves symptoms in patients with a hyperkinetic gallbladder when compared to those managed nonoperatively and if there were variables predictive of symptom improvement with or without cholecystectomy. MATERIALS AND METHODS: This retrospective study included patients from 3 academic hospitals in the Atlanta metro area between the years 2006 and 2018. All patients with an EF >80% were included. Following voluntary exclusion patients were contacted by phone. Each patient was administered a questionnaire regarding their surgical history, medical management, and current symptom profile via Otago score. Institutional Institutional Review Board approval was obtained. RESULTS: 4785 HIDA scans were performed, and 194 reported an EF >80% (incidence 15.7%). 96% of these scans were reported as normal by the radiologist. 68 patients were able to be contacted by phone and completed the questionnaire. 18 patients underwent cholecystectomy, and 89% reported that their symptoms attributed to gallbladder disease were no longer present. 50 patients did not undergo cholecystectomy, and alternate diagnoses, medication prescriptions, diet modification, emergency department visits, and Otago score were higher in this cohort. DISCUSSION: Patients who undergo cholecystectomy for a diagnosis of hyperkinetic gallbladder, on average, report improvement in symptoms when compared to patients managed nonoperatively. This study supports the practice of reporting and managing hyperkinetic gallbladders as a pathologic entity.

Yttrium-90 dosimetry and implications on tumour response and survival after radioembolisation of chemo-refractory hepatic metastases from breast cancer.

PURPOSE: The aim of the study was to evaluate the effects of tumour dose on tumour response and overall survival (OS) in patients with chemo-refractory metastatic breast cancer (MBC) to the liver undergoing yttrium-90 radioembolisation (Y90 RE). MATERIALS AND METHODS: In 20 consecutive patients with chemo-refractory MBC to the liver undergoing 33 total Y90 RE resin treatments, volumes of interest were drawn around the five largest tumours of the targeted liver lobe on post-Y90 RE Bremsstrahlung single-photon emission computed tomography/computed tomography using MIM software v.6.9 (MIM Software, Cleveland, Ohio, USA) and dose-volume histograms were calculated. Response Evaluation Criteria in Solid Tumours (RECIST) was used to determine tumour response at 3 months. Receiver operating characteristics (ROC) curves were used to determine thresholds for various dosimetry parameters. Kaplan-Meier estimation was used to determine OS. RESULTS: Overall, 11 of 33 (33%) Y90 RE treatments resulted in complete or partial response according to RECIST criteria with a median OS of 20.97 months compared to 11.73 months for nonresponders (P = 0.003). Mean tumour dose, defined as the aggregate tumour dose of up to the five largest tumours in the targeted lobe, was the most predictive of tumour response with the highest area under the ROC curve of 0.967. Mean tumour dose >70 Gy had 91% sensitivity and 100% specificity for predicting tumour response. Patients with mean tumour dose >70 Gy experienced a median OS of 16.1 months vs. 12.8 months for those who did not (P = 0.008). CONCLUSION: For patients with chemo-refractory breast cancer with liver metastases, achieving a mean tumour dose >70 Gy is a significant predictor of tumour response and prolonged OS.

Comparison of Tc-99m MAA Planar Versus SPECT/CT Imaging for Lung Shunt Fraction Evaluation Prior to Y-90 Radioembolization: Are We Overestimating Lung Shunt Fraction?

PURPOSE: To compare lung shunt fraction (LSF) prior to Y-90 radioembolization calculated using planar imaging versus SPECT/CT in patients with hepatocellular carcinoma (HCC). METHODS: A single institution retrospective analysis of technetium-99m macroaggregated albumin (Tc-99m MAA) LSF studies for 293 consecutive patients with HCC between 2013 and 2018 was performed. LSF using planar imaging (PLSF) was compared to retrospectively calculated LSF using SPECT/CT (SLSF) via semiautomated segmentation using MIM v.6.9. Sub-analyses of patients were performed based on PLSF range, tumor size, BCLC stage, and Child-Pugh (C-P) score. Mean LSF absolute discrepancy between sub-groups was analyzed. Comparisons were performed using paired t tests and linear regression analysis. RESULTS: Mean PLSF, 8.27%, was greater than mean SLSF, 3.27% (p < 0.001). When categorizing patients by PLSF ranges of < 10%, 10-19.9%, and ≥ 20%, PLSF remained greater than SLSF in all subgroups (p's < 0.001). Patients with PLSF ≥ 20% had a greater absolute discrepancy with SLSF (13.31%) compared to patients with PLSF < 20% (4.74%; p < 0.0001). LSF absolute discrepancy was greater for patients with a maximum liver tumor size ≥ 5.0 cm (5.59%) compared to a liver tumor size < 5.0 cm (4.40%; p = 0.0076). For all BCLC grades and C-P scores, PLSF was greater than SLSF. A greater LSF discrepancy existed for patients with a worse C-P score (C-P A: 4.78%, C-P B/C: 6.12%; p = 0.0081), but not BCLC stage (0/A/B: 4.87%, C: 4.56%; p = 0.5993). CONCLUSION: In patients with HCC, SLSF is significantly lower compared to PLSF, with a greater discrepancy among patients with a PLSF ≥ 20%, tumor size ≥ 5 cm, and worse C-P score. LEVEL OF EVIDENCE: Level 3, Retrospective Study.