Radioactive Microspheres Research Articles

Radioactive microspheres—see and destroy

Radioactive microspheres—see and destroy

Nebivolol treatment increases splanchnic blood flow and portal pressure in cirrhotic rats via modulation of nitric oxide signalling

We evaluated the effects of nebivolol, a third generation beta-blocker capable of increasing NO-bioavailability on portal pressure, and on splachnic and systemic haemodynamics in a cirrhotic portal hypertensive rat model. Male Sprague-Dawley rats underwent sham operation (SO) or bile duct ligation (BDL). When cirrhosis was fully developed, the animals were orally treated with low-dose (5 mg/kg) or high-dose (10 mg/kg) nebivolol (NEBI) or vehicle (VEH) for 7 days. Heart rate (HR), mean arterial pressure (MAP), portal pressure (PP) and superior mesenteric artery blood flow (SMABF) were measured. Portosystemic collateral blood flow (PSCBF) was quantified using radioactive microspheres. Hepatic and splanchnic NOx levels and GSH/GSSG ratios (RedOx state) were determined using commercially available kits. BDL-VEH rats showed increased HR, PP and PSCBF, whereas MAP was decreased compared to SO-VEH rats. Nebivolol significantly reduced HR both in SO (P < 0.001) and BDL (P < 0.001) rats. BDL-NEBI animals had significantly higher PP (15.5 vs. 12.6 mmHg; P = 0.006) and SMABF (5.3 vs. 3.7 ml/min/100g; P = 0.016) than BDL-VEH animals. The increase in PP and SMABF was noted both in low-dose and high-dose BDL-NEBI rats. While no beneficial effects on hepatic RedOx state were observed, splanchnic NOx levels were significantly increased by NEBI treatment in a dose-dependent manner. Nebivolol treatment did not affect PSCBF in SO and BDL animals. Nebivolol increases portal pressure in cirrhotic animals by increasing splanchnic blood flow via modulation of NO signalling. Portosystemic collateral blood flow remained unchanged. These data do not support the use of nebivolol for treatment of cirrhotic patients with portal hypertension.

Do We have Enough Direct Evidence to Postulate that Abnormally Shaped Red Blood Cells Impair Microvascular Blood Flow in Critical Conditions?

abnormal RBCs were produced in-vitro but not as a result of a real critical condition. The conclusions received in these two studies were confirmed in “pure” in-vivo experiments by Machiedo et al. [18]. The authors performed exchange transfusion in rats with blood obtained animals rats subjected to trauma-hemorrhagic shock or to sham shock. The reduced RBC deformability in rats that experienced traumahemorrhagic shock and normal RBC deformability in those who were subjected to sham shock was confirmed by laser ektacytometry. However, the authors did not investigate RBC shape in transfused blood. It was demonstrated that microvascular blood flow in the lungs, spleen, and intestine measured by radioactive microsphere technique was significantly lower in rats subjected to the infusion of traumahemorrhagic shock blood than in those that were infused with sham blood.

Coronary microembolization during early reperfusion: infarct extension, but protection by ischaemic postconditioning

Reperfusion injury following acute myocardial infarction impacts not only on the myocardium but also on the coronary microcirculation, and microembolization from the culprit lesion contributes to microvascular obstruction. Prior experimental studies have not accounted for microembolization in ischaemia/reperfusion injury and not considered microembolization as a confounder and target of protection by ischaemic postconditioning. We therefore investigated the impact of microembolization during reperfusion on infarct size and cardioprotection by postconditioning. Anaesthetized, open-chest pigs were subjected to 90 min low-flow ischaemia. Immediate full reperfusion (n = 8) served as the control. Microembolization was induced by intracoronary infusion of 42 µm microspheres with the onset of reperfusion (n = 8). In a second step, postconditioning was induced by six cycles of 20s reperfusion/20s re-occlusion without (n = 8) and with superimposed microembolization (n = 8). Transmural blood flow and area at risk were determined by radioactive microspheres, infarct size by triphenyl tetrazolium chloride staining. Area at risk and transmural blood flow were not different between groups. Microembolization increased infarct size from 32 ± 3% of the area at risk to 47 ± 3% (P < 0.05). Embolizing particles were re-distributed away from the central infarcted area and accumulated in the infarct border, thus contributing to infarct extension. Postconditioning reduced infarct size without (21 ± 3%; P < 0.05 vs. immediate full reperfusion) and also with additional microembolization (26 ± 5%; P < 0.05 vs. immediate full reperfusion and microembolization); embolizing particles did not accumulate in the infarct border. Microembolization at reperfusion augments infarct size, but postconditioning in the presence of microembolization still reduces infarct size and attenuates infarct expansion.

Anatomical basis and histopathological changes resulting from selective internal radiotherapy for liver metastases

BackgroundKnowledge that liver tumours preferentially take their blood supply from the arterial blood supply rather than the portal venous system can be used for local delivery of treatment or for...

41. Radio-embolisation treatment of inoperable and borderline operable liver metastases from colorectal cancer

The commonest cause of death from advanced colorectal cancer is disease progression of hepatic metastases. Down-sizing metastases with systemic chemotherapy to make them amenable to resection can improve overall survival for patients. Radio-embolisation (RE) is a technique for administering resin or glass microspheres that contain yttrium-90 to unresectable primary or secondary hepatic malignancies internally via the liver's arterial supply in a single procedure. Since the radioactive microspheres are implanted in or immediately adjacent to the malignancies, RE is a form of brachytherapy.

Holmium-166 radioembolisation in patients with unresectable, chemorefractory liver metastases (HEPAR trial): a phase 1, dose-escalation study

The efficacy of radioembolisation for the treatment of liver tumours depends on the selective distribution of radioactive microspheres to tumorous tissue. The distribution of holmium-166 ((166)Ho) poly(L-lactic acid) microspheres can be visualised in vivo by both single-photon-emission CT (SPECT) and MRI. In this phase 1 clinical trial, we aimed to assess the safety and the maximum tolerated radiation dose (MTRD) of (166)Ho-radioembolisation in patients with liver metastases. Between Nov 30, 2009, and Sept 19, 2011, patients with unresectable, chemorefractory liver metastases were enrolled in the Holmium Embolization Particles for Arterial Radiotherapy (HEPAR) trial. Patients were treated with intra-arterial (166)Ho-radioembolisation in cohorts of three patients, with escalating aimed whole-liver absorbed doses of 20, 40, 60, and 80 Gy. Cohorts were extended to a maximum of six patients if dose-limiting toxicity occurred. Patients were assigned a dose in the order of study entry, with dose escalation until dose-limiting toxicity was encountered in at least two patients of a dose cohort. Clinical or laboratory toxicities were scored according to the National Cancer Institute's Common Terminology Criteria for Adverse Events version 3.0. The primary endpoint was the MTRD. Analyses were per protocol. This study is registered with ClinicalTrials.gov, number NCT01031784. 15 patients underwent (166)Ho-radioembolisation at doses of 20 Gy (n=6), 40 Gy (n=3), 60 Gy (n=3), and 80 Gy (n=3). Mean estimated whole-liver absorbed doses were 18 Gy (SD 2) for the 20 Gy cohort, 35 Gy (SD 1) for the 40 Gy cohort, 58 Gy (SD 3) for the 60 Gy cohort, and 73 Gy (SD 4) for the 80 Gy cohort. The 20 Gy cohort was extended to six patients because of the occurrence of dose-limiting toxicity in one patient (pulmonary embolism). In the 80 Gy cohort, dose-limiting toxicity occurred in two patients: grade 4 thrombocytopenia, grade 3 leucopenia, and grade 3 hypoalbuminaemia in one patient, and grade 3 abdominal pain in another patient. The MTRD was identified as 60 Gy. The most frequently encountered laboratory toxicities (including grade 1) were lymphocytopenia, hypoalbuminaemia, raised alkaline phosphatase, raised aspartate aminotransferase, and raised gamma-glutamyltransferase, which were all noted in 12 of 15 patients. Stable disease or partial response regarding target lesions was achieved in 14 of 15 patients (93%, 95% CI 70-99) at 6 weeks and nine of 14 patients (64%, 95% CI 39-84) at 12 weeks after radioembolisation. Compared with baseline, the average global health status and quality of life scale score at 6 weeks after treatment had decreased by 13 points (p=0·053) and by 14 points at 12 weeks (p=0·048). In all patients, technetium-99m ((99m)Tc)-macro-aggregated albumin SPECT, (166)Ho scout dose SPECT, and (166)Ho treatment dose SPECT showed similar patterns of the presence or absence of extrahepatic deposition of activity. (166)Ho-radioembolisation is feasible and safe for the treatment of patients with unresectable and chemorefractory liver metastases and enables image-guided treatment. Clinical (166)Ho-radioembolisation should be done with an aimed whole-liver absorbed dose of 60 Gy.

InSIRT trial: Single-center phase II study of yttrium-90 radioactive resin microspheres in the treatment of liver-predominant metastatic colorectal adenocarcinoma after failure of first-line combination chemotherapy.

e14079 Background: Liver metastases develop in half of colorectal cancer (CRC) cases and once metastatic, ~90% die due to their consequences. We are evaluating the aggressive management of liver metastases through the incorporation of selective internal radiation therapy (SIRT) using Yttrium-90 (Y-90) radioactive microspheres after evidence of progressive disease following 1st-line FOLFOX ± bevacizumab. Optimal timing for microsphere treatment relative to chemotherapy is not clearly established. Methods: Subjects with predominant hepatic metastatic CRC despite 1st-line FOLFOX based therapy ± bevacizumab are eligible. Interventional radiology and nuclear medicine assess the liver lesions and the subject receives SIRT followed by 2nd-line FOLFIRI 4-6 weeks after the final SIRT. Results: To date, 9 metastatic CRC subjects have been treated and 10 subjects enrolled (goal 30 subjects). One subject was withdrawn due to progressive lung metastases. 4 of 9 subjects (45%) achieved PFS at 6 mos and average TTP is 7 months(0.7-21.3 mos). Overall treatment has been well tolerated, except one possible study related SAE of liver failure. The OS endpoint has not been achieved. Conclusions: Historically, 2nd-line FOLFIRI has achieved a 2.5 mos median PFS. Our preliminary results of 9 subjects with metastatic CRC show a PFS up to 21.3 monthsand 45% PFS at 6 mos. These encouraging results demonstrate the utility of an innovative direct approach to metastatic CRC after failure of 1st-line combination chemotherapy. Based on our promising preliminary results, our aim is to enroll 30-35 metastatic CRC patients. [Table: see text]

U.S. patients receiving resin 90Y microspheres for unresectable colorectal liver metastases: A multicenter study of 506 patients.

3590 Background: Implantation of radioactive microspheres via the hepatic artery with Yttrium-90 (90Y) is termed “radioembolization, (RE)”. Resin microspheres were FDA cleared for use in colorectal liver metastases (mCRC) in 2002. Rapid worldwide acceptance of this therapy has resulted in greater than 30,000 procedures conducted in the past 10 years. This investigator-initiated study focuses on RE treatment outcomes in US-only patients since 2002. Methods: A retrospective multi-institutional study was designed to analyze the outcome of consecutively treated mCRC patients undergoing RE by experienced treatment centers in the USA using resin 90Y microspheres. IRB approval was obtained by each center with independent data collection and analyses. Primary endpoints: CTC 3.0ae toxicity, RECIST response and survival; baseline treatment parameters, prior chemotherapy, and liver directed therapies. Results: 506 patients at 10 institutions (193 M, 313 F) received 770 RE treatments; median age = 60.4 years (20.8 – 91.9 years); median number of RE treatments per patient = 1.0 (1-5 treatments). Active extrahepatic disease was present at first RE in 34.8% of patients. The majority (90%) of patients received prior chemotherapy, with 30.6% also having undergone prior hepatic surgery/ablative procedures. Median follow up after RE = 8.4 mo. (0.4 – 67.6 mo.) with median survival = 10.1 mo. (95% CI 9.1 – 12.0). For first RE treatment, median tumor volume was 146.0 mL (2.8 – 3228.0 mL). Median radiation activity delivered = 1.18 GBq (0.12 – 2.29 GBq), lung shunt median = 4.8 % (.02 – 45%). Total grade 1-3 events were 32% GI, 44% fatigue and 1% liver failure. Only 2.4% of all treatments required an overnight stay post-procedure. Conclusions: The modern USA experience of 90Y therapy for unresectable, heavily pretreated mCRC liver metastases is encouraging with a median survival of 10.1 months after first RE procedure. Toxicity was mild and of short duration in most patients. RECIST response is being analyzed currently as are data of additional patients.

A New Catheter for Tumor-Targeting With Radioactive Microspheres in Representative Hepatic Artery Systems—Part II: Solid Tumor-Targeting in a Patient-Inspired Hepatic Artery System

In this second part, the methodology for optimal tumor-targeting is further explored, employing a patient-inspired hepatic artery system which differs significantly from the idealized configuration discussed in Part I. Furthermore, the fluid dynamics of a microsphere supply apparatus is also analyzed. The best radial catheter positions and particle-release intervals for tumor targeting were determined for both the idealized and patient-inspired configurations. This was accomplished by numerically analyzing generated particle release maps (PRMs) for ten equally spaced intervals throughout the pulse. As in Part I, the effects of introducing a catheter were also investigated. In addition to the determination of micro-catheter positioning and, hence, optimal microsphere release, a microsphere-supply apparatus (MSA) was analyzed, which transports the particles to the catheter-nozzle, considering different axial particle injection functions, i.e., step, ramp, and S-curve. A refined targeting methodology was developed which demonstrates how the optimal injection region and interval can be determined with the presence of a catheter for any geometric configuration. Additionally, the less abrupt injection functions (i.e., ramp and S-curve) were shown to provide a more compact particle stream, making them better choices for targeting. The results of this study aid in designing the smart micro-catheter (SMC) in conjunction with the MSA, bringing this innovative treatment procedure one step closer to implementation in clinical practice.

A New Catheter for Tumor Targeting With Radioactive Microspheres in Representative Hepatic Artery Systems. Part I: Impact of Catheter Presence on Local Blood Flow and Microsphere Delivery

Building on previous studies in which the transport and targeting of (90)Y microspheres for liver tumor treatment were numerically analyzed based on medical data sets, this two-part paper discusses the influence of an anchored, radially adjustable catheter on local blood flow and microsphere delivery in an idealized hepatic artery system (Part I). In Part II a patient-inspired case study with necessary conditions for optimal targeting of radioactive microspheres (i.e., yttrium 90) onto liver tumors is presented. A new concept of optimal catheter positioning is introduced for selective targeting of two daughter-vessel exits potentially connected to liver tumors. Assuming laminar flow in rigid blood vessels with an anchored catheter in three controlled positions, the transient three-dimensional (3D) transport phenomena were simulated employing user-enhanced engineering software. The catheter position as well as injection speed and delivery function may influence fluid flow and particle transport. Although the local influences of the catheter may not be negligible, unique cross-sectional particle release zones exist, with which selectively the new controlled targeting methodology would allow optimal microsphere delivery. The insight gained from this analysis paves the way for improved design and testing of a smart microcatheter (SMC) system as well as new investigations leading to even more successful treatment with (90)Y microspheres or combined internal radiation and chemotherapy.

Abstract 3692: Single center phase II study of yttrium-90 radioactive resin microspheres in the treatment of liver predominant metastatic colorectal adenocarcinoma after failure of 1st-line combination chemotherapy

Abstract Background: Colorectal cancer is the fourth most commonly diagnosed cancer and the second leading cause of cancer death. Liver metastases develop in half of all the colorectal cancer (CRC) cases and cause death in ∼90% of patients. We are evaluating the treatment of liver metastases through the incorporation of selective internal radiation therapy (SIRT) using Yttrium-90 radioactive microspheres for subjects with liver progressive disease following failure of first-line FOLFOX (± bevacizumab). We are presenting our preliminary data for the phase II study evaluating the tumor response rates, PFS, and long-term safety and toxicity to SIRT following FOLFOX (± bevacizumab) prior to FOLFIRI. Methods: Subjects with predominantly hepatic metastatic CRC whose disease progressed on first-line FOLFOX (± bevacizumab) based therapy are eligible. Interventional radiology and nuclear medicine assess the liver lesions and the subject receives their SIRT treatment(s) followed by second-line FOLFIRI based therapy 4-6 weeks after the final SIRT treatment. Optimal timing for microsphere treatment relative to chemotherapy is not clearly established. Results: To date, 9 metastatic CRC subjects have been treated and 11 subjects enrolled (goal 30 subjects). One subject was withdrawn due to progressive lung metastases. Four of 8 subjects (50%) achieved PFS at 6 months and average TTP is 6.7 months (0.7-17.3 months). Overall treatment has been well tolerated, but one possible study related SAE of liver failure occurred (Subject 8). The OS endpoint has not been achieved. Conclusions: Historically, second-line FOLFIRI has achieved a 2.5 months median PFS. In 8 subjects with predominant liver metastatic CRC, we have observed 50% PFS at 6 months. These encouraging results demonstrate the utility of an innovative direct approach to metastatic CRC after failure of first-line combination chemotherapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3692. doi:1538-7445.AM2012-3692

Preparation of 137Cs Microspheres for Their Use in Computer Automated Radioactive Particle Tracking Studies

This paper describes a method for the preparation of 137Cs labeled mordenite-coated spheroidal alumina particles [∼ 0.7 mm (ϕ)] for their utility in the computer automated radioactive particle tracking technique for the calibration of detectors. Mordenite was coated successfully, in situ, on alumina microspheres under hydrothermal conditions and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analyses. A thorough optimization of experimental parameters such as pH of the adsorbing solution, reaction time, carrier concentration, reaction volume, and temperature, etc., were carried out to arrive at the conditions resulting in optimum impregnation of 137Cs activity into the microspheres. Under the optimized conditions, about 2.7–3.1 MBq (73–85 μCi) of 137Cs could be impregnated on individual microspheres in a reproducible manner. The radioactive microspheres were subsequently covered with a thin layer of polystyrene to prevent the dispersion of 137Cs activity during use.

InSIRT trial: Single-center phase II study of yttrium-90 radioactive resin microspheres in the treatment of liver-predominant metastatic colorectal adenocarcinoma after failure of first-line combination chemotherapy.

685 Background: Liver metastases develop in half of colorectal cancer (CRC) cases and once metastatic ~90% die due to consequences from the hepatic metastases. We are evaluating the aggressive management of liver metastases through the incorporation of selective internal radiation therapy (SIRT) using yttrium-90 radioactive microspheres after evidence of progressive disease following first-line FOLFOX ± bevacizumab. Optimal timing for microsphere treatment relative to chemotherapy is not clearly established. We present preliminary data of a phase II study evaluating tumor response rates to SIRT following FOLFOX ± bevacizumab and prior to FOLFIRI. Methods: Subjects with predominant hepatic metastatic CRC despite first-line FOLFOX based therapy ± bevacizumab are eligible. Interventional radiology and nuclear medicine assess the liver lesions and the subject receives SIRT followed by second-line FOLFIRI (without bevacizumab) 4-6 weeks after the final SIRT. The primary objective is PFS at 6 mos and secondary objectives include: OS, tumor response rates, and toxicity. Results: To date, 8 metastatic CRC subjects have been treated and 9 subjects enrolled (goal 30 subjects). One subject was withdrawn due to progressive lung metastases. 4 of 8 subjects (50%) achieved PFS at 6 mos and average TTP is 6.7 mos (0.7-17.3 mos). Overall treatment has been well tolerated, but one possible study related SAE of liver failure occurred (subject 8). The OS endpoint has not been achieved. Conclusions: Historically, second-line FOLFIRI has achieved a 2.5 mos median PFS. In 8 subjects with liver predominant metastatic CRC, we have observed 50% PFS at 6 mos. These encouraging results demonstrate the utility of an innovative direct approach to metastatic CRC after failure of first-line combination chemotherapy. [Table: see text]

90Y radioembolization for neuroendocrine cancers liver metastases provides sustained therapeutic effect with minimal toxicity.

343 Background: Radioembolization (RE) is the delivery of radioactive microspheres (90Y) via the hepatic artery, which permanently implant preferentially in metastatic lesions, sparing adjacent normal liver. Metastatic neuroendocrine tumors in the liver are a common clinical problem which can be treated with RE. It is an outpatient procedure performed with increasing frequency worldwide for a variety of solid tumor types. Methods: A single institution retrospective review of all neuroendocrine patients treated with radioactive resin microspheres to control hepatic metastases. Details reviewed included: specifics of treatment and delivery, RECIST response at 3 and 6 months, acute and delayed radiation toxicities by CTC3ae, and analyses of tumor and radiation factors related to response and liver control. Results: A total of 56 patients; 26 male, 30 female, received a total of 85 separate treatments with resin 90Y microspheres. Treatment volume was all hepatic tumors with each treatment, usually selective whole liver in one fraction. Whole liver in 1 treatment comprised 86%, right lobe only in 10% and left lobe in 4%. Thirty-six patients (64.3%) received 1 treatment, 12 patients 2 fractions, 7 patients 3 fractions, and 1 patient 4 fractions. The median activity of 90Y delivered was 1.49 GBq (0.35 – 2.9 GBq). BSA approach was used for pretreatment activity calculations for all patients, with median of 100% planned activity delivered (26% - 147%). No grade 4 toxicities occurred, and only two grade 3 events were found (gastric ulcers). The median follow up is 24.2 mo. (1 – 93.4 mo.). RECIST at 3 and 6 months: CR 6.5%, SD 49.1%, PR 42.6% and PD 1.6%. Delivered activity (GBq) was associated with PR at 3 months (p=0.07, two-tailed t-test). Conclusions: Our experience is consistent with other published reports confirming the efficacy and low toxicity of this liver-directed ablative approach for unresectable neuroendocrine carcinomas. Multiple treatments to the whole liver were well tolerated. The BSA method of pretreatment radioactivity estimation is useful and safe in this tumor type.

Integrating Radioembolization (90Y Microspheres) Into Current Treatment Options for Liver Tumors

Liver-directed therapies for unresectable cancers in the liver are evolving with increased efficacy and decreasing toxicity. One of these approaches uses radioactive microspheres delivered to hepatic tumors via the hepatic artery system-radioembolization. Use of this therapy is rapidly increasing worldwide with over 20,000 patients treated thus far. Therefore, greater understanding of its potential and optimal positioning of this therapy in the multimodality management of cancers affecting the liver is needed. This task has been undertaken by a group of the most experienced clinicians in radioembolization from multiple disciplines involved in this therapy.

Cerebral blood flow quantification in the rat: a direct comparison of arterial spin labeling MRI with radioactive microsphere PET

BackgroundArterial spin labeling magnetic resonance imaging (ASL-MRI) has been recognised as a valuable method for non-invasive assessment of cerebral blood flow but validation studies regarding quantification accuracy by comparison against an accepted gold standard are scarce, especially in small animals. We have conducted the present study with the aim of comparing ASL flow-sensitive alternating inversion recovery (FAIR)-derived unidirectional water uptake (K1) and 68Ga/64Cu microsphere (MS)-derived blood flow (f) in the rat brain.MethodsIn 15 animals, K1and f were determined successively in dedicated small animal positron emission tomography and MR scanners. The Renkin-Crone model modified by a scaling factor was used for the quantification of f and K1.ResultsBelow about 1 mL/min/mL, we obtain an approximately linear relationship between f and K1. At higher flow values, the limited permeability of water at the blood brain barrier becomes apparent. Within the accessed dynamic flow range (0.2 to 1.9 mL/min/mL), the data are adequately described by the Renkin-Crone model yielding a permeability surface area product of (1.53±0.46) mL/min/mL.ConclusionThe ASL-FAIR technique is suitable for absolute blood flow quantification in the rat brain when using a one-compartment model including a suitable extraction correction for data evaluation.Trial registration24-9168.21-4/2004-1 (registered in Freistadt Sachsen, Landesdirektion Dresden)

Radionuclide purity assessment and calibration of 90Y(177Lu) glass particles using gamma-ray spectrometry

Intra-hepatic administration of radioactive glass microspheres is a treatment for patients with primary liver cancer and hepatic metastases. The purpose of this study was radionuclide purity assessment of new glass particles containing two radionuclide, 90Y as a therapeutic source and also 177Lu as a source of diagnostic gamma. For the mixed source, activity measurement using a dose calibrator cannot be used and we need new calibration methods. YAS (Yb) and YAS compositions were sol–gel derived glass particles and production of 90Y (177Lu) and 90Y particles was performed using the Tehran Research Reactor. The radionuclide purity was carried out using γ-spectrometry with HPGe detector. A non-destructive spectroscopic assay was employed due to a newly updated low uncertainty positron branching ratio of 90Y that emit 511 keV annihilation radiations. In another method, a new calibration of 90Y using a non-destructive spectroscopic assay of 88Y were investigated. Potential radionuclide impurity include: 88Y, 152Eu, 60Co with activity 100, 50 and 5 Bq per 1 mg of that are not harmful for patients due to delivering radioactive particles about 20–50 mg in 90Y(177Lu) glass microspheres. Among of radionuclide impurity, 152Er with a half life of 13.54 years and 88Y with a half life of 106.65 days was important in the residual delivery device. For calibration of 90Y with monitoring of 511 keV, errors were12.2–21%. In calibration of 90Y using gamma spectroscopic assay of 88Y, there was an error less than 14%. Spectroscopic assay of 88Y can be performed easily and has more repeat for our purpose.

Hepatic Radioembolization Complicated by Radiation Cholecystitis

Biliary complications following yttrium-90 ((90)Y) radioembolization are rare, and radiation-induced cholecystitis requiring intervention represents an even smaller proportion of these complications, reportedly occurring in fewer than 1% of patients treated with (90)Y [1]. However, its implications are serious, as the treatment of radiation cholecystitis may require cholecystectomy in patients otherwise considered poor surgical candidates. While biliary complications such as intrahepatic biliary strictures or bilomas may be unavoidable in the course of treating hepatic malignancies due to local field effects of radiation, radiation cholecystitis results from non-target embolization of radioactive microspheres. Meticulous attention to anatomic detail and catheter position may be adequate in preventing this avoidable complication. Herein we discuss the clinical, radiographic, and pathologic findings, as well as the outcome, of a patient who experienced radiation cholecystitis following (90)Y radioembolization.

Radioactive Microsphere Set-Up and Radiation Safety

Radioactive Microsphere Set-Up and Radiation Safety