Administration Of Radiopharmaceuticals Research Articles

Internal Audit to Monitor the Injected Activity in PET/CT Using Control Charts.

In an effort to limit the risks associated with medical radiation exposure, the last century witnessed the development of dose control mechanisms, recommended by the International Commission on Radiological Protection. This organization recommends the optimization of radiation protection to provide the highest level of safety that may reasonably be achievable. Adhering to the "as low as reasonably achievable" principle, the purpose of this study was to monitor the 18F-FDG injected activity in PET and optimize the radiation protection through an internal audit process. This monitoring allows the identification of opportunities for improvement in patient care and safety, as well as to establish a periodic review of the medical unit reference levels. The methodology is based on short run Quesenberry (Q) statistics and normalized nonconstant sample size (Z-chart) control charts. Anonymized data from 512 patients were selected from a set of 18F-FDG PET/CT (Siemens, Biograph 6) examinations performed during 10 months. The analyzed variable was the ratio between the 18F-FDG injected activity (MBq) and patient weight (kg). Mean injected 18F-FDG activity was 347.811 ± 64.967 MBq corresponding to a mean effective dose of 6.608 ± 1.234 mSv. The ratio between the 18F-FDG injected activity and the body mass of patients was reduced from 5.243 ± 0.716 to 5.171 ± 0.672 MBq/kg during the statistical data analysis. The study demonstrates that control charts can be a useful tool to signal situations where patients receive an activity significantly different from the standard practice in a medical unit. The use of joint control charts is a suitable tool for detecting nonoptimized radiopharmaceutical administration. This analysis provides opportunities to evaluate and improve the quality of practice in nuclear medicine. This methodology constitutes an internal audit that may help health care professionals to make appropriate decisions to ensure all patients receive the safest and most appropriate care.

First-in-human study of 225actinium mti-201 (225Ac-MTI-201) in metastatic uveal melanoma (UM).

TPS9612 Background: Prognosis in metastatic uveal melanoma (UM) has historically been poor approximating 1 year from diagnosis. Tebentafusp is the only approved systemic agent for HLA-A*02:01 positive metastatic UM, and novel therapies are needed. The melanocortin-1 receptor (MC1R) receptor is highly expressed in UM with limited expression in normal tissues. Actinium-225 (225Ac) is an alpha particle emitting radionuclide ideal for targeted ligand binding due to high linear energy transfer and limited free path (<100 µm) in tissue. We developed a novel MC1R targeted radiopharmaceutical 225Ac-MTI-201, and demonstrated high biostability, affinity, MC1R-specific cytotoxicity with defined dosimetry and pharmacokinetics in pre-clinical studies (1). Murine efficacy studies of UM showed significant delay of tumor growth and improved survival compared to controls. Methods: This is a single institution first-in-human phase I study (NCT05496686) of 225Ac-MTI-201 in metastatic UM. The primary objective is to determine the safety of a single intravenous dose of 225Ac-MTI-201 relative to radioactivity dose. Secondary endpoints include 1) pharmacokinetics (PK) and clearance of 225Ac-MTI-201, 2) objective response rate and duration, progression-free survival, and overall survival in metastatic UM. Salient eligibility criteria include: 1) age ≥18 years; 2) histologically confirmed metastatic UM with progression after at least 1 prior line of therapy; 3) measurable disease per Response Evaluation Criteria in Solid Tumors version 1.1; 4) Eastern Cooperative Oncology Group performance status of ≤1; 5) adequate marrow, renal and hepatic function; 6) no more than 25% of bone marrow treated with prior radiotherapy. Patients will receive a single dose of 225Ac-MTI-201 under appropriate guidelines and precautions for administration of radiopharmaceuticals. Pre-injection and post-injection PK sampling at defined intervals are undertaken. There are 12 dose levels for 225Ac-MTI-201 being investigated ranging from 4.7 microcurie (µCi) to 1327 µCi. Dose escalation is done using a modified continual re-assessment method with a cohort size of one based on dose limiting toxicity (DLT) assessment within 28 days of drug administration using CTCAE v5.0. Definitions of DLT include G4 neutropenia or febrile neutropenia, G4 thrombocytopenia or G3 thrombocytopenia with clinically significant bleeding, > G3 non-hematological toxicity with selected exceptions, laboratory abnormalities that satisfy Hy’s law, or any death not related to underlying disease or extraneous cause. Response assessments are undertaken with cross-sectional imaging every 8 weeks in year 1, and every 12 weeks in year 2. This study is currently open for enrollment. Dose levels 1-4 have been completed without DLT. 1. Tafreshi, J Nucl Med 2019. Clinical trial information: NCT05496686 .

Association of cardiac mechanical dyssynchrony indices with data of dynamic single-photon emission computed tomography of the myocardium: the role of the time interval between the stress test and recording

Introduction. According to ECG-synchronized myocardial perfusion imaging (MPI) mechanical dyssynchrony (MD) is a sensitive marker of impaired myocardial perfusion. However, its direct comparison with indicators of myocardial blood flow reserve (MFR) according to single-photon emission computed tomography (SPECT) was not carried out. Traditional MPI protocols imply a long gap between stress test and image acquisition, during which stress-induced changes may pass. It is potentially possible to reduce the time interval down to 5 minutes.Aim: To investigate the relationship between early and delayed MD indices and the data of MFR by means of SPECT.Material and Methods. The study included 20 patients with suspected coronary heart disease, preserved left ventricular ejection fraction (> 55%) and without obstructive coronary artery lesions (< 50%) according to multislice computed coronary angiography. All patients underwent dynamic SPECT (dSPECT) according to a two-day rest/stress protocol. Gated MPI was performed 60 minutes after radiopharmaceutical administration. Myocardial blood flow and reserve, as well as phase histogram standard deviation (PSD, degree) and phase histogram bandwidth (HBW, degree) from 5 minutes after radiopharmaceutical administration were obtained from the dSPECT data by postprocessing. Perfusion data as well as MD indices (PSD, HBW) were obtained from delayed images. Based on dSPECT data, patients were divided into 2 groups: with preserved (MFR ≥ 2.0) and reduced (MFR < 2.0) myocardial blood flow reserve.Results. Correlation analysis showed that MD indices on stress test in early scan had a stronger association with MFR (PSD ρ = –0.68, p < 0.001; HBW ρ = –0.68, p = 0.001) compared to those in delayed scan (PSD ρ = –0.38, p = 0.019; HBW ρ = –0.44, p = 0.005). According to multivariate regression analysis, PSD on stress test at early scan was the only independent predictor of reduced MFR (OR 1.29 (1.1; 1.53)). Stress PSD > 22° obtained at early scanning had a sensitivity of 81% and specificity of 87% (AUC = 0.86, p < 0.001) in predicting of reduced MFR.Conclusion. Left ventricular mechanical dyssynchrony indices obtained by early post-stress gated MPI have a stronger association with myocardial blood flow reserve indices.

Assessment of arterial blood flow in the microvasculature of the lower extremities in patients with chronic ischemia using a single-photon emission computed tomography (SPECT)

Introduction. Obliterating atherosclerosis of the lower extremity vessels is a chronic, steadily progressive disease of the leg arteries, with a high risk of limb amputation and death. Timely diagnosis and adequate treatment will help slow the disease progression, maintain the patient’s good health for a long time and avoid complications. Purpose. To study arterial blood flow in the microvasculature of the lower extremities, to qualitatively and quantitatively assess perfusion disturbances in functionally significant muscles of the lower extremities. Material and methods. Radionuclide examination of the main vessels and microvasculature of the lower extremities was performed in 36 patients, five of them with a diagnosis of lower extremity obliterating atherosclerosis in dynamics. Radiopharmaceuticals was administered through a catheter installed endovascularly above the aortic bifurcation when patients underwent arteriography of the lower extremity vessels, which also involves intra-arterial administration of a radiopaque contrast agent. Results. When processing the radiological study results, we visually assessed the distribution of radiopharmaceuticals in the vascular bed of the lower extremities, identified the asymmetry in the accumulation of radiopharmaceuticals as a percentage, quantified the accumulation of radiopharmaceutical pulses in the projection of the pelvic, thigh, leg and foot muscles, determining the level of accumulation in each of the areas of interest as a percentage. The radiological study results and direct aortic arteriography of the lower extremities with determination of the level of arterial stenosis confirmed the ischemic nature of the pain syndrome; and in the control study, the effectiveness of treatment with an improvement in perfusion parameters. Conclusions. Intra-arterial administration of radiopharmaceuticals makes it possible to assess the condition of the peripheral arterial bed, which has a significant role in the prognosis of lower extremity atherosclerosis and the results of reconstructive interventions. The method makes possible a hybrid topometric comparison of arterio-perfusion maps for diagnosis, planned treatment and monitoring of its results in dynamics.

A patient journey audit tool (PJAT) to assess quality indicators in a nuclear medicine service

PurposeTo develop a nuclear medicine specific patient journey audit tool (PJAT) to survey and audit patient journeys in a nuclear medicine department such as staff interaction with patients, equipment, quality of imaging and laboratory procedures, patient protection, infection control and radiation safety, with a view to optimising patient care and providing a high-quality nuclear medicine service.MethodsThe PJAT was developed specifically for use in nuclear medicine practices. Thirty-two questions were formulated in the PJAT to test the department’s compliance to the Australian National Safety and Quality Health Service Standards, namely clinical governance, partnering with consumers, preventing and controlling health care infection, medication safety, comprehensive care, communicating for safety, blood management and recognising and responding to acute deterioration. The PJAT was also designed to test our department’s adherence to diagnostic reference levels (DRL). A total of 60 patient journey audits were completed for patients presenting for nuclear medicine, positron emission tomography and bone mineral density procedures during a consecutive 4-week period to audit the range of procedures performed. A further 120 audits were captured for common procedures in nuclear medicine and positron emission tomography during the same period. Thus, a total of 180 audits were completed. A subset of 12 patients who presented for blood labelling procedures were audited to solely assess the blood management standard.ResultsThe audits demonstrated over 85% compliance for the Australian national health standards. One hundred percent compliance was noted for critical aspects such as correct patient identification for the correct procedure prior to radiopharmaceutical administration, adherence to prescribed dose limits and distribution of the report within 24 h of completion of the imaging procedure.ConclusionThis PJAT can be applied in nuclear medicine departments to enhance quality programmes and patient care. Austin Health has collaborated with the IAEA to formulate the IAEA PJAT, which is now available globally for nuclear medicine departments to survey patient journeys.

The 45th Report on Survey of the Adverse Reaction to Radiopharmaceuticals (The 48th Survey in 2022)

This survey was performed in order to investigate the incidence of adverse reactions to radiopharmaceuticals in FY2022 in Japan. It was based on responses to questionnaires sent to nuclear medicine institutions. Replies were obtained from 1,004 institutions out of 1,181 to which the questionnaire had been sent. A total of 911,977 radiopharmaceutical administrations were reported. Seventeen cases of adverse reactions were reported. The incidence of adverse reactions per 100,000 cases was 1.9 . No case of defective products was reported.

Novel Artificial Intelligence Tool for Real-time Patient Identification to Prevent Misidentification in Health Care.

Errors in the identification of true patients in a health-care facility may result in the wrong dose or dosage being given to the wrong patient at the wrong site during radiotherapy sessions, radiopharmaceutical administration, radiological scans, etc. The aim of this article is to reduce the error in the identification of correct patients by implementation of the Python deep learning-based real-time patient identification program. The authors utilized and installed Anaconda Prompt (miniconda 3), Python (version 3.9.12), and Visual Studio Code (version 1.71.0) for the design of the patient identification program. In the field of view, the area of interest is merely face detection. The overall performance of the developed program is accomplished over three steps, namely image data collection, data transfer, and data analysis, respectively. The patient identification tool was developed using the OpenCV library for face recognition. This program provides real-time patient identification information, together with the other preset parameters such as disease site, with a precision of 0.92%, recall rate of 0.80%, and specificity of 0.90%. Furthermore, the accuracy of the program was found to be 0.84%. The output of the in-house developed program as "Unknown" is provided if a patient's relative or an unknown person is found in restricted region. This Python-based program is beneficial for confirming the patient's identity, without manual interventions, just before therapy, administering medications, and starting other medical procedures, among other things, to prevent unintended medical and health-related complications that may arise as a result of misidentification.

Reaching the target dose with one single 131 I-mIBG administration in high-risk neuroblastoma: The determinant impact of the primary tumour.

131 I-metaiodobenzylguanidine (131 I-mIBG) effectiveness in children with metastasised neuroblastoma (NB) is linked to the effective dose absorbed by the target; a target of 4Gy whole-body dose threshold has been proposed. Achieving this dose often requires administering 131 I-mIBG twice back-to-back, which may cause haematological toxicity. In this study, we tried identifying the factors predicting the achievement of 4Gy whole-body dose with a single radiopharmaceutical administration. Children affected by metastatic NB and treated with a high 131 I-mIBG activity (>450MBq (megabecquerel)/kg) were evaluated retrospectively. Kinetics measurements were carried out at multiple time points to estimate the whole-body dose, which was compared with clinical and activity-related parameters. Seventeen children (12 females, median age 3years, age range: 1.5-6.9years) were included. Eleven of them still bore the primary tumour. The median whole-body dose was 2.88Gy (range: 1.63-4.22Gy). Children with a 'bulky' primary (>30mL) received a higher whole-body dose than those with smaller or surgically removed primaries (3.42±0.74 vs. 2.48±0.65Gy, respectively, p=.016). Conversely, the correlation between activity/kg and the whole-body dose was moderate (R: 0.42, p=.093). In the multivariate analysis, the volume of the primary tumour was the most relevant predictor of the whole-body dose (p=.002). These data suggest that the presence of a bulky primary tumour can significantly prolong the 131 I-mIBG biological half-life, effectively increasing the absorbed whole-body dose. This information could be used to model the administered activity, allowing to attain the target dose without needing a two-step radiopharmaceutical administration.

Radiopharmaceutical administration practices—Are they best practice?

BackgroundThe nuclear medicine community has stated that they are using best practices to gain venous access and administer radiopharmaceuticals, and therefore do not contribute to extravasations. We tested this hypothesis qualitatively and quantitatively by evaluating four different perspectives of current radiopharmaceutical administration practices: (1) clinical observations of nuclear medicine technologists on the job, (2) quality improvement (QI) projects, (3) a high-level survey of current practices in 10 acute care hospitals, (4) intravenous (IV) access site data for 29,343 procedures. These four areas were compared to the gold standard of pharmaceutical administration techniques.ResultsFrom clinical observations of radiopharmaceutical administrations in adult populations, technologists extensively used 24-gauge peripheral intravenous catheters (PIVCs) and butterfly needles. They also performed direct puncture (straight stick). Technologists predominantly chose veins in areas of flexion (hand, wrist, and antecubital fossa), rather than forearm vessels for IV access placement; in many circumstances, antecubital fossa vessels are chosen first, often without prior assessment for other suitable vessels. For selecting the injection vein, technologists sometimes used infrared vein finders but primarily performed blind sticks. Review of QI projects suggested that smaller gauge needles were contributing factors to extravasations. Additionally, the review of surveys from 10 hospitals revealed an absence of formalized protocols, training, knowledge, and skills necessary to ensure the safety/patency of IV devices prior to the administration of radiopharmaceuticals. Finally, findings from a review of IV access data for 29,343 procedures supported the observations described above.ConclusionsWe expect that nuclear medicine technologists have the best intentions when providing patient care, but many do not follow venous access best practices; they lack formal protocols, have not received the latest comprehensive training, and do not use the best placement tools and monitoring equipment. Thus, the presumption that most nuclear medicine technologists use best practices may not be accurate. In order to improve radiopharmaceutical administration and patient care, the nuclear medicine community should update technical standards to address the most recent peripheral IV access and administration best practices, provide technologists with vascular visualization tools and the proper training, develop and require annual vascular access competency, and provide active monitoring with center and patient-specific data to create ongoing feedback.

Estimation of the relative biological effectiveness (RBE) of the 177Lu − DOTA − iPSMA radiopharmaceutical

Relative biological effectiveness is a radiobiological parameter relevant in radiotherapy planning and useful in evaluating the physiological impact of radiation in different tissues. Targeted radionuclide therapy allows the selective and specific deposition of higher radiation doses in a noninvasive way and without collateral effects through the administration of radiopharmaceuticals. Lu−DOTA−177(hydrazinylnicotinoyl−Lys−(Nal)−NH−CO−NH−Glu) also called Lu−iPSMA177 is a third generation radiopharmaceutical composed by a peptide that recognizes the prostate-specific membrane antigen (PSMA), a membrane protein overexpressed in several types of cancer and that mediates the radiopharmaceutical's recognition of cancer cells. The present study reports radiobiological parameters of Lu−iPSMA177 and demonstrates the superiority of targeted radiopharmaceuticals over external radiotherapy treatment options in terms of their relative biological effectiveness. The relative biological effectiveness value of 1.020±0.003 for the LINAC, estimated by fitting the linear-quadratic model equation to the resulting survival curves, was like those of 1.25±0.04,1.060±0.005and1.00±0.04 obtained by an alternative method in relation to the mean lethal doses at 90, 80 or 60 survival percent respectively. While the relative biological effectiveness values of 5.65±0.13,4.72±0.27and2.87±0.19 estimated for Lu−iPSMA177 were significantly higher than those for the LINAC. The results confirm that the biological effect produced by the deposition of a radiation absorbed dose delivered by the LINAC can be induced with a quarter of that dose using Lu−iPSMA177 due to the energy distribution, dose-rate and energy fluence.

P11.68.A INTRA-ARTERIAL ADMINISTRATION OF [68GA]GA-PSMA-11 IN MALIGNANT PRIMARY AND SECONDARY BRAIN TUMOURS; A NOVEL APPROACH THAT SIGNIFICANTLY INCREASES TUMOUR UPTAKE AND POTENTIAL OF/FOR THERANOSTIC STRATEGIES

Abstract BACKGROUND Primary and secondary brain tumours carry a dismal prognosis and require new treatment strategies. First studies into novel radionuclide therapies have thus far yielded little success, potentially because of limitary uptake in tumour upon intravenous (IV) administration. The aim of the present study was to show that intra-arterial (IA) administration of radiopharmaceuticals will lead to much higher uptake and, consequently, to higher delivered dose to the tumour, which convincingly outweighs the systemic non-target uptake. MATERIAL AND METHODS Ten patients with malignant brain tumours (n=5 high-grade glioma (HGG), n=5 brain metastasis (BM)) twice received 1.5 MBq/kg [68Ga]Ga-PSMA-11 followed by PET-MRI at 90, 165 and 240 minutes post-administration, first upon IV and subsequently upon selective IA administration, with a median interval time of 5 days. Standardised uptake values (SUVs) were calculated for tumour, and non-target sites (contralateral healthy brain, salivary glands and liver) using volumes of interest (VOIs). Tumour-to-liver (T/L), tumour-to-salivary gland (T/SG) uptake-ratios and simulated achievable tumour doses with either [177Lu]Lu- or [225Ac]Ac-PSMA were calculated for each patient. Paired T-test and Wilcoxon signed rank-test were performed to compare outcomes. RESULTS All patients showed significantly higher uptake in tumour following IA administration compared to IV administration, with a median SUVmax of 142.8 (range: 31.3-336.8) versus 10.5 (range: 5.1-17.1, P=0.005). Healthy brain showed no significant uptake, independent of the route of administration (SUVmean range: <0.1-0.1). Uptake at non-target sites was comparable following IA and IV administration, resulting in more favourable T/SG-ratios of 8.4 (median, range: 1.8-18.9) for IA versus 1.8 (0.9-7.0) for IV; P=0.005 and T/L-ratios of 26.5 (7.4-68.7) for IA versus 1.8 (0.9-7.0) for IV; P=0.005. Simulations showed a maximum delivered dose to the tumours for a single treatment cycle to be 68 Gy (median, range: 5-282) for [177Lu]Lu- and 78 Gy (5-174) for [225Ac]Ac-PSMA when administered intra-arterially, versus 10 Gy (1-37) and 18 Gy (1-49), when administered intra-venously. CONCLUSION Selective IA administration of radiopharmaceuticals in malignant brain tumours leads to a significant and therapeutically relevant increase in target to non-target uptake ratios. This observation opens new avenues for the development of theranostic strategies for patients with HGG and BM whom we, to date, have no curative treatment to offer.

The prognostic value of 99m Tc-glucosamine imaging in patients with rheumatoid arthritis: a single center prospective study.

Poor prognostic factors in rheumatoid arthritis (RA) are associated with a more severe form of the disease. Nuclear medicine functional imaging has shown remarkable merit at identifying active disease in patients with RA and is increasingly being used in this regard. However, its prognostic value has not been evaluated thoroughly. We aimed to assess the prognostic value of technetium-99m ( 99m Tc-) glucosamine imaging in patients with RA. Twenty-two participants diagnosed by an experienced rheumatologist with RA were recruited for inclusion in the study. Blood samples were obtained from each participant for baseline C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody titer. On the same day, each participant was injected with 20-25 millicurie (mCi) of 99m Tc-glucosamine. Planar and single-photon emission computed tomography images of known disease sites were acquired up to 2 hours after radiopharmaceutical administration. Affected joints were qualitatively assessed and graded for 99m Tc-glucosamine uptake and compared with blood results. All participants affected joints had an increased uptake of the radiopharmaceutical, with 14 (63.6%) having elevated RF and anti-CCP antibody titers. Eight of the 14 patients with increased RF and anti-CCP antibodies had grade 3 uptake of 99m Tc-glucosamine. The remaining 6 had grade 2 uptake. A significant correlation between higher grade uptake and increased levels of RF and anti-CCP antibodies ( P = 0.031) was observed. We found a strong correlation between high-grade disease on imaging and the presence of RF and anti-CCP antibodies in patients with RA.

A pilot study to estimate the Pediatric radiation dose during thyroid, renal, and bone scan

Pediatric patients benefited from nuclear medicine (NM) results. NM provides information regarding the general and localized function of the body's organs, systems, and lesions. This includes applications in the bone, neuro, renal, cardiovascular, endocrine, and other organ systems, as well as in detecting and managing cancer. The administration of radiopharmaceuticals associated with exposure to ionizing radiation is a necessary component of NM practice. This study aims to estimate the Pediatric radiation dose during thyroid, renal, and bone scans. Methods The study involved 161 pediatric patients who underwent thyroid, renal, and bone scans using Tc-99m radionuclide. Effective dose has been estimated using web-based software depending on conductive activity.Effective dose has been estimated using computer software depending on conductive activity. The results show patient dose information from thyroid, renal, and bone scans. For a thyroid scan, the patient's age was 12.26 ± 3.65 years, the patient's height was 1.43 ± 0.20 cm, and the patient's weight was 41.87 ± 16.56 kg. The activity was 2.89 ± 1.12 mCi, and the effective dose for thyroid was 1.92 ± 0.81 mSv. For the renal scan, the patient's age was 6.55 ± 4.83 years, height was 1.09 ± 0.37 cm, and weight was 24.01 ± 18.19 kg. The activity was 2.41 ± 0.88 mCi, and the effective dose was 0.72 ± 0.19 mSv. for a bone scan patient's age was 11 ± 4.12 years, the patient's height was 1.4 ± 0.19 cm, the patient's 33.64 ± 14.3 kg. the activity 11.46 ± 3.64 mCi and the effective dose 3.1 ± 0.61 mSv.Implementing national guidelines must improve the practice and patient safety, and the relationship between administered activity and patient weight needs to be better understood.

Leveraging Radiopharmaceutical Programmatic Collaboration for Management of Pretherapy and On-treatment Urinary Incontinence.

Many parenteral radiopharmaceuticals available as anticancer therapy are filtered by the kidneys and excreted in the urine. Here, physician leaders of radiation medicine, nuclear medicine/molecular imaging, and the radiotheranostics programs as well as radiation safety officers, collaborated to develop a decision-making guideline for the administration of therapeutic radiopharmaceuticals in patients with pretherapy or day-of-treatment incontinence. We discussed challenges and opportunities in the screening of patients in urine collection strategies according to grade of urinary incontinence and in subsequent coordination of care. Lutetium-177 ( 177 Lu)-based radiopharmaceutical therapies provided clinical examples of how our procedures were operationalized. Our key management issues of urinary incontinence were cutaneous radiation injury and redness, infection, or pain. In response, we developed clinical practice guidelines for the recognition and management of incontinence-related adverse events. Common adverse events of urinary incontinence were noted in this study. Our how-to guideline for the safe administration of therapeutic radiopharmaceuticals for patients with urinary incontinence warrants further investigation and should continue to be evaluated across all radiopharmaceutical therapy agents.

Radioactivity of biological samples of patients treated with 90Y-DOTATOC

Dosimetric studies in Nuclear Medicine are very important, especially with new therapeutic methods, the number of which has increased significantly with the Theranostic approach (determining diagnostic-therapeutic pairs where similar molecules are labelled with different isotopes in order to diagnose and treat malignant diseases). Peptide receptor radionuclide therapy (PRRT) has been used successfully for many years to treat neuroendocrine tumors (NET). 90Y-DOTATOC is one of the radiopharmaceuticals used frequently in this type of therapy.In this work, blood and urine samples from 13 patients treated with 90Y-DOTATOC were measured by a liquid scintillation beta counter (LSC). Calibration of the beta counter for this type of measurement was done and all results are presented in the paper. The presented paper also provides a methodology for determining the measurement uncertainty for this type of measurement.Immediately after the administration of radiopharmaceuticals, the activity in the blood was different from 6.31% to 88.9% of the applied radioactivity, while 3 h after the termination of the application, the average value of radiopharmaceuticals in the blood was only 3.84%. The activity in the excreted urine depended on the time when the patients urinated after the therapy. It was measured that as much as 58% of the applied radioactivity was excreted in the first urine after the therapy in a patient who urinated 4.5 h after the completed application of the therapy. In most patients, the highest urine activity was in the first 10 h after the application, while the activities after that time were negligibly low.The described methodology of measuring and evaluating activity in blood and excreted urine can be applied to other radiopharmaceuticals used in nuclear medicine. It could be useful for researchers for dosimetric assessments in clinical application of PRRT.

Duration of Breastfeeding Interruption in Nuclear Medicine Procedures.

The recommendation for the duration of breastfeeding interruption after radiopharmaceutical administration has not been standardized and varies among the guidance documents and publications in the literature. Methods: A working group consisting of 3 staff physicians, 2 fellows, and 2 technologists was designated to update the institutional recommendations on breastfeeding interruption based on the review of the guidance documents and the literature. Results: Our institutional recommendations on the duration of breastfeeding interruption for 54 radiopharmaceuticals are presented in 4 summary tables. For completeness, we also include other radiopharmaceuticals with available information. Conclusion: The detailed recommendation summary on breastfeeding might be helpful to other centers.

Close contact restriction periods for patients who have received iodine-131 therapy for differentiated thyroid cancer

Patients treated with radionuclide therapy usually require restrictions on certain activities for a period of time following treatment to optimise protection of the public and ensure the legal dose limit is not exceeded. Software may be used to calculate necessary restriction periods for an individual based on longitudinal dose rate measurements from the time of radiopharmaceutical administration. A spreadsheet program has been used for this purpose in Australian hospitals for the last two decades. However, this spreadsheet has a limitation in that it uses an approximation in the calculation of dose from a contact pattern, which affects the calculated restriction period. A computer program called Dorn was developed that provides the same functionality as the spreadsheet but without this approximation. Proffered radiation safety advice from Dorn and the spreadsheet were compared. Advice from the spreadsheet and Dorn were compared for 55 patients who underwent iodine-131 therapy for differentiated thyroid cancer. The restriction periods for caring for infants, close contact with children and sleeping with a partner were typically about 13 h longer in Dorn than in the spreadsheet, but in some cases were over a week shorter or a month longer. If the Dorn program is used clinically in place of the spreadsheet, some patients will enjoy shorter restriction periods and the therapy provider can be more confident in their compliance with regulatory requirements and best practice. Dorn is freely available from https://doi.org/jg5f.

Radioisotope Safety: 12 Real-life Scenarios

HomeRadioGraphicsVol. 43, No. 4 PreviousNext Nuclear MedicineRadioGraphics FundamentalsRadioisotope Safety: 12 Real-life ScenariosHarit Kapoor1 , Vaibhav Gulati2, M. Elizabeth OatesHarit Kapoor1 , Vaibhav Gulati2, M. Elizabeth OatesAuthor AffiliationsFrom the Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Tex (H.K.); Imaging Associates, National Heart Institute, New Delhi, India (V.G.); and Department of Radiology, University of Kentucky College of Medicine, UK HealthCare/Chandler Medical Center, Lexington, Ky (M.E.O.).Address correspondence to H.K. (email: [email protected]).Harit Kapoor1 Vaibhav Gulati2M. Elizabeth OatesPublished Online:Mar 23 2023https://doi.org/10.1148/rg.220077MoreSectionsFull textPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In AbstractThis slide presentation provides high-yield fundamental concepts, facts, and figures related to radioisotope safety through the use of illustrated real-life scenarios to improve situational recall in daily clinical practice.Suggested Readings1. ACR-AAPM radiation safety officer resources. https://www.acr.org/-/media/ACR/Files/Radiology-Safety/Radiation-Safety/ACRAAPM-RSO-Resources.pdf. Revised 2021. Accessed May 24, 2022. Google Scholar2. Baldwin JA, Bag AK, White SL, Palot-Manzil FF, O’Malley JP. All you need to know as an authorized user. AJR Am J Roentgenol 2015;205(2):251–258. Crossref, Medline, Google Scholar3. Chen MY. Radiation protection and regulations for the nuclear medicine physician. Semin Nucl Med 2014;44(3):215–228. Crossref, Medline, Google Scholar4. Cho SG, Kim J, Song HC. Radiation safety in nuclear medicine procedures. Nucl Med Mol Imaging 2017;51(1):11–16. Crossref, Medline, Google Scholar5. European Association of Nuclear Medicine. Guide on best practices in nuclear medicine. https://www.eanm.org/publications/technologists-guide/. Accessed May 24, 2022. Google Scholar6. Marengo M, Martin CJ, Rubow S, Sera T, Amador Z, Torres L. Radiation safety and accidental radiation exposures in nuclear medicine. Semin Nucl Med 2022;52(2):94–113. Crossref, Medline, Google Scholar7. Mettler FA, Guiberteau MJ. Essentials of Nuclear Medicine and Molecular Imaging. 7th ed. Philadelphia, Pa: Elsevier, 2018. Google Scholar8. O’Malley J, Zeissman H, Thrall JH. Nuclear Medicine and Molecular Imaging: The requisites. 5th ed. Philadelphia, Pa: Elsevier, 2019. Google Scholar9. Saha GB. Radiation Safety in Nuclear Medicine: A practical, concise guide. Cham, Switzerland: Springer, 2019. Crossref, Google Scholar10. U.S. Nuclear Regulatory Commission. Guidance document on radiopharmaceutical administration during lactation. https://www.nrc.gov/docs/ML1923/ML19232A081.pdf. Updated 2020. Accessed May 24, 2022. Google Scholar11. U.S. Nuclear Regulatory Commission. The Nuclear Medicine Licensee Toolkit. https://www.nrc.gov/materials/miau/med-use-toolkit/faqs-part35.html#3. Accessed May 24, 2022. Google Scholar12. U.S. Nuclear Regulatory Commission. Regulations, guidance and communications page. https://www.nrc.gov/materials/miau/regs-guides-comm.html. Accessed May 24, 2022. Google ScholarArticle HistoryReceived: Apr 5 2022Revision requested: May 12 2022Revision received: June 8 2022Accepted: June 17 2022Published online: Mar 23 2023 FiguresReferencesRelatedDetailsAccompanying This ArticleRadioisotope Safety: 12 Real-Life ScenariosMar 23 2023Default Digital Object SeriesRecommended Articles RSNA Education Exhibits RSNA Case Collection Vol. 43, No. 4 Slide PresentationMetrics Altmetric Score PDF download

Active monitoring improves radiopharmaceutical administration quality

IntroductionIn 2016, our center adopted technology to routinely monitor 18F-FDG radiopharmaceutical administrations. Within six months of following basic quality improvement methodology, our technologists reduced extravasation rates from 13.3% to 2.9% (p < 0.0001). These same technologists administer other radiopharmaceuticals (without monitoring technology) for general nuclear medicine procedures in a separate facility at the clinic. Our hypothesis was that they would apply 18F-FDG lessons-learned to 99mTc-MDP administrations and that 99mTc-MDP manual injection extravasation rate would be consistent with the ongoing 18F-FDG manual injection extravasation rate (3.4%). We tested our hypothesis by following the same quality improvement methodology and added monitoring equipment to measure extravasation rates for 99mTc-MDP administrations.Results816 99mTc-MDP administrations were monitored during 16-month period (four 4-month periods: A, B, C, D). Period A (first four months of active monitoring) extravasation rate was not statistically different from the Measure Phase extravasation rate of the previously completed PET/CT QI Project: 12.75% compared to 13.3% (p-0.7925). Period A extravasation rate was statistically different from Period C (months 9–12) extravasation rate and Period D (months 13–16) extravasation rate: 12.75% compared to 2.94% and to 3.43% (p < 0.0001). During Period C and D technologists achieved extravasation rates comparable to the longstanding manual 18F-FDG injection extravasation rate (3.4%).ConclusionOur initial hypothesis, that awareness of a problem and the steps need to correct it would result in process improvement, was not accurate. While those factors are important, they are not sufficient. Our findings suggest that active monitoring and the associated display of results are critical to quality improvement efforts to reduce and sustain radiopharmaceutical extravasation rates.

Transparency – a patient-centric view on radiopharmaceutical extravasations

Most radiopharmaceuticals are intravenously administered during nuclear medicine imaging or therapy procedures. When a nuclear medicine clinician delivers some or all of a radioactive drug into a patient's healthy tissue rather than the vein as intended, a patient experiences an extravasation. Radiopharmaceutical extravasations provide zero patient benefit and considerable potential downsides, depending on the severity of the extravasations. What nuclear medicine patients want and need regarding the administration of radiopharmaceuticals is transparency. And yet in the year 2023, little transparency exists regarding these extravasations. From the patient perspective, transparency regarding extravasations is essential to improving care, ensuring radiation protection, reducing health inequities, and untangling the deeply disturbing and irregular relationship between the nuclear medicine community and their regulating body, The U.S. Nuclear Regulatory Commission. Transparency is also critical to help address many other questions regarding radiopharmaceutical extravasations.