Reverse cardiac remodelling and dysfunction in A97S transthyretin cardiac amyloidosis after tafamidis treatment.

Transthyretin cardiomyopathy (ATTR-CM) is an under-recognized cause of heart failure, but it has received increasing attention due to the availability of treatment options. We present a case of hereditary transthyretin cardiomyopathy (A97S, an under-represented variant in current clinical studies) who presented with heart failure. Timely diagnosis and intervention with tafamidis demonstrated reversed cardiac remodelling via multiple imaging techniques (echocardiography, cardiac magnetic resonance imaging and technetium-99m pyrophosphate scintigraphy). The echocardiography and cardiac magnetic resonance imaging demonstrated improved global strain. Cardiac magnetic resonance imaging showed decreased extracellular volume. The technetium-99m pyrophosphate scintigraphy demonstrated decreased heart-to-contralateral ratio. This case highlights the potential reversible effect of tafamidis on A97S amyloidosis cardiomyopathy.

Genotoxicity Associated with 131I and 99mTc Exposure in Nuclear Medicine Staff: A Physical and Biological Monitoring Study.

Nuclear medicine staff are constantly exposed to low doses of ionizing radiation. This study investigated the level of genotoxic effects in hospital employees exposed to routinely used 131I and 99mTc in comparison with a control group. The study compared the results of physical and biological monitoring in peripheral blood lymphocytes. The effects of confounding factors, such as smoking status and physical activity, were also considered. Physical dosimetry monitoring revealed differences in the individual annual effective dose as measured by finger ring dosimeter and whole-body dosimeter between the 131I- and 99mTc-exposed groups. The DNA damage studies revealed differences between the groups in terms of excess premature chromosome condensation (PCC) fragments and tail DNA. Physical activity and smoking status differentiated the investigated groups. When assessed by the level of physical activity, the highest mean values of tail DNA were observed for the 99mTc group. When assessed by work-related physical effort, excess PCC fragments were significantly higher in the 131I group than in the control group. In the investigated groups, the tail DNA values were significantly different between non-smokers and past or current smokers, but excess PCC fragments did not significantly differ by smoking status. It is important to measure exposure to low doses of ionizing radiation and assess the potential risk from this exposure. Such investigations support the need to continue epidemiological and experimental studies to improve our understanding of the mechanisms of the health effects of radionuclides and to develop predictive models of the behavior of these complex systems in response to low-dose radiation.

A double-blind, double-dummy, randomized controlled, multicenter trial of 99Tc-methylene diphosphonate in patients with moderate to severe rheumatoid arthritis.

BACKGROUND: Clinical observational studies revealed that 99Tc-methylene diphosphonate (99Tc-MDP) could reduce joint pain and swollenness in rheumatoid arthritis (RA) patients. This multicenter, randomized, double-blind, double-dummy study aimed to evaluate the effects of 99Tc-MDP plus methotrexate (MTX) vs. MTX alone or 99Tc-MDP alone on disease activity and structural damage in MTX-naïve Chinese patients with moderate to severe RA. METHODS: Eligible patients with moderate to severely active RA were randomized to receive 99Tc-MDP plus MTX (n = 59) vs. MTX (n = 59) alone or 99Tc-MDP (n = 59) alone for 48 weeks from six study sites across four provinces in China. The primary outcomes were the American College of Rheumatology 20% improvement (ACR20) response rates at week 24 and changes in modified total Sharp score at week 48. RESULTS: At week 24, the proportion of participants achieving ACR20 was significantly higher in the MTX + 99Tc-MDP combination group (69.5%) than that in the MTX group (50.8%) or 99Tc-MDP group (47.5%) (P = 0.03 for MTX + 99Tc-MDP vs. MTX, and MTX + 99Tc-MDP vs.99Tc-MDP, respectively). The participants in the MTX + 99Tc-MDP group and the 99Tc-MDP group had significantly less important radiographic progression than the participants in the MTX group over the 48 weeks (MTX + 99Tc-MDP vs. MTX: P = 0.03, 99Tc-MDP vs. MTX: P = 0.03, respectively). There was no significant difference in terms of adverse events (AEs) among the groups. No serious AEs were observed. CONCLUSIONS: This study demonstrated that the combination of 99Tc-MDP with MTX inhibited structural damage and improved disease activity in RA patients compared with MTX and 99Tc-MDP monotherapies, without increasing the rate of AEs. Additional clinical studies of 99Tc-MDP therapy in patients with RA are warranted. TRIAL REGISTRATION: Chictr.org, ChiCTR-IPR-14005684; http://www.chictr.org.cn/showproj.aspx?proj=10088.

A double-blind, double-dummy, randomized controlled, multicenter trial of 99Tc-methylene diphosphonate in patients with moderate to severe rheumatoid arthritis / 中华医学杂志(英文版)

BACKGROUND@#Clinical observational studies revealed that 99Tc-methylene diphosphonate (99Tc-MDP) could reduce joint pain and swollenness in rheumatoid arthritis (RA) patients. This multicenter, randomized, double-blind, double-dummy study aimed to evaluate the effects of 99Tc-MDP plus methotrexate (MTX) vs. MTX alone or 99Tc-MDP alone on disease activity and structural damage in MTX-naïve Chinese patients with moderate to severe RA.@*METHODS@#Eligible patients with moderate to severely active RA were randomized to receive 99Tc-MDP plus MTX (n = 59) vs. MTX (n = 59) alone or 99Tc-MDP (n = 59) alone for 48 weeks from six study sites across four provinces in China. The primary outcomes were the American College of Rheumatology 20% improvement (ACR20) response rates at week 24 and changes in modified total Sharp score at week 48.@*RESULTS@#At week 24, the proportion of participants achieving ACR20 was significantly higher in the MTX + 99Tc-MDP combination group (69.5%) than that in the MTX group (50.8%) or 99Tc-MDP group (47.5%) (P = 0.03 for MTX + 99Tc-MDP vs. MTX, and MTX + 99Tc-MDP vs.99Tc-MDP, respectively). The participants in the MTX + 99Tc-MDP group and the 99Tc-MDP group had significantly less important radiographic progression than the participants in the MTX group over the 48 weeks (MTX + 99Tc-MDP vs. MTX: P = 0.03, 99Tc-MDP vs. MTX: P = 0.03, respectively). There was no significant difference in terms of adverse events (AEs) among the groups. No serious AEs were observed.@*CONCLUSIONS@#This study demonstrated that the combination of 99Tc-MDP with MTX inhibited structural damage and improved disease activity in RA patients compared with MTX and 99Tc-MDP monotherapies, without increasing the rate of AEs. Additional clinical studies of 99Tc-MDP therapy in patients with RA are warranted.@*TRIAL REGISTRATION@#Chictr.org, ChiCTR-IPR-14005684; http://www.chictr.org.cn/showproj.aspx?proj=10088.

Classification of the Multiple Stages of Parkinson's Disease by a Deep Convolution Neural Network Based on 99mTc-TRODAT-1 SPECT Images.

Single photon emission computed tomography (SPECT) has been employed to detect Parkinson's disease (PD). However, analysis of the SPECT PD images was mostly based on the region of interest (ROI) approach. Due to limited size of the ROI, especially in the multi-stage classification of PD, this study utilizes deep learning methods to establish a multiple stages classification model of PD. In the retrospective study, the 99mTc-TRODAT-1 was used for brain SPECT imaging. A total of 202 cases were collected, and five slices were selected for analysis from each subject. The total number of images was thus 1010. According to the Hoehn and Yahr Scale standards, all the cases were divided into healthy, early, middle, late four stages, and HYS I~V six stages. Deep learning is compared with five convolutional neural networks (CNNs). The input images included grayscale and pseudo color of two types. The training and validation sets were 70% and 30%. The accuracy, recall, precision, F-score, and Kappa values were used to evaluate the models' performance. The best accuracy of the models based on grayscale and color images in four and six stages were 0.83 (AlexNet), 0.85 (VGG), 0.78 (DenseNet) and 0.78 (DenseNet).

Scintigraphic assessment of arterial embolism at mixed thrombin and technetium 99m injection therapy for femoral pseudoaneurysms.

BACKGROUND: Clinically evident arterial thrombosis is rare following thrombin injection therapy for femoral pseudoaneurysm. However, it is unclear to what extent injected thrombin may pass to the ipsilateral lower limb arteries. AIMS: To assess if technetium 99m injected at the time of thrombin injection for femoral artery pseudoaneurysm therapy passes into the adjacent lower limb arteries. METHODS: This was a prospective trial with institutional review board approval. Four consecutive patients with common femoral pseudoaneurysms and failed manual compression were enrolled. Under real-time colour flow doppler ultrasound, a mixture of 1000 IU thrombin and approximately 200 MBq technetium 99m was injected in 0.1-mL doses into the pseudoaneurysm until thrombosis occurred. Gamma camera imaging of the syringe before injection, the injected groin after thrombosis and the syringe after injection were performed. Analysis of the gamma camera information was performed to determine the amount of technetium 99m deposited in the arterial tree. RESULTS: All the procedures were technically successful. A mean of 33% (range 3-50%; SD 21) of the administered technetium 99m dose was deposited in the arterial circulation during pseudoaneurysm therapy. No clinically evident arterial thrombosis was identified. CONCLUSION: Technetium 99m is routinely deposited in the arterial circulation following injection of a mixture of thrombin and technetium for therapy of common femoral artery pseudoaneurysms. This suggests that arterial passage of thrombin is more common than clinically evident.

Pertecnectato de Sodio Tc99m para el diagnóstico de pacientes con cáncer / Sodium Pertechnectate Tc99m for the diagnosis of cancer patients

INTRODUCCIÓN: El cáncer produce una carga importante en salud en todos los países y es un problema que escala rápidamente. De acuerdo al GLOBOCAN 2018 por la Agencia internacional para investigación en cáncer (IARC por sus siglas en inglés) hubieron 18.1 millones de nuevos casos y un total de 9.6 millones de muertes por cáncer globalmente en el año 2018, llegando en los últimos cinco años a una prevalencia de 15 millones de personas. A. Cuadro clínico: Muchos autores investigaron la eficacia de biomarcadores circulantes y técnicas de imagen molecular para el diagnóstico no invasivo del cáncer. Las metodologías pueden variar desde intervenciones locales como toma de biopsias, estudios imagenológicos desde rayos x, tomografías, resonancia nuclear, medicina nuclear que diagnostica haciendo uso de la radiación, comprendiendo técnicas para obtener imágenes de los órganos internos o del esqueleto. Para lograr estas imágenes, la medicina nuclear utiliza elementos radiactivos, también llamados radioisótopos que se producen generalmente en reactores nucleares. En la actualidad existen instrumentos llamados gamma-cámaras o cámaras de centelleo, que cuentan con un gran número de detectores que operan simultáneamente. En medicina, dos de los radioisótopos más comúnmente utilizados son el tecnecio 99m y el yodo 131. B. Tecnología sanitaria: El pertecnetato de sodio Tecnecio 99m (99m Tc) es un agente radionucleótido compuesto de un oxoanion con la formula química TcO4- que emite radiación gamma, se usa como agente diagnostico radioactivo en varios tejidos, particularmente en el sistema gastrointestinal, cardiovascular, circulatorio cerebral, cerebro, tiroides y óseo. De acuerdo a la solicitud hecha para la presente ETS, sólo evaluaremos a pacientes con neoplasias malignas en general y a los cuales se les indique gammagrafía por sospecha de afectación ósea. OBJETIVO: Evaluar la eficacia y seguridad, así como documentos relacionados a la decisión de cobertura de Tc99m para pacientes oncológicos con indicación de gammagrafías por sospecha de afectación ósea. METODOLOGÍA: Se realizó una búsqueda en las principales bases de datos bibliográficas: MEDLINE, LILACS, COCHRANE, así como en buscadores genéricos de Internet incluyendo Google Scholar y TRIPDATABASE. Adicionalmente, se hizo una búsqueda dentro de la información generada por las principales instituciones internacionales de hepatología y gastroenterología y agencias de tecnologías sanitarias que realizan revisiones sistemáticas (RS), evaluación de tecnologías sanitarias (ETS) y guías de práctica clínica (GPC). RESULTADOS: Se seleccionaron cinco GPC. No se encontraron ECAs, ETS ni evaluaciones económicas de la región que evaluaran el uso de Tc99m para pacientes oncológicos con indicación de gammagrafías por sospecha de afectación ósea. Se encontraron cinco GPC (Europa 2003, Europa 2016, Reino Unido 2018, México 2014, Estados Unidos de América 2017) que recomiendan la gammagrafía como una técnica para la identificación de lesiones óseas en oncología. Todas estas, sólo mencionan el uso de gammagrafía con Tc99m y no mencionan otros radioisótopos. CONCLUSIONES: La información comparativa del pertecnetato de sodio Tecnecio 99m en gammagrafía ósea en pacientes oncológicos comparado con otro radioisótopo es escasa. De acuerdo a las GPC recabadas se observa que existe un consenso en la utilidad y beneficio del uso de la gammagrafía en pacientes con patologías oncológicas para la identificación de afectación ósea. Todos los documentos mencionan únicamente el uso de pertecnetato de sodio Tecnecio 99m para este propósito.

Combining Diagnostic Imaging and Pathology for Improving Diagnosis and Prognosis of Cancer.

In the era of personalized medicine, the management of oncological patients requires a translational and multidisciplinary approach. During early phases of cancer development, biochemical alterations of cell metabolism occur much before the formation of detectable tumour masses. Current molecular imaging techniques, targeted to the study of molecular kinetics, employ molecular tracers capable of detecting cancer lesions with both high sensitivity and specificity while also providing essential information for both prognosis and therapy. On the contrary, complementary and crucial information is provided by histopathological examination and ancillary techniques such as immunohistochemistry. Thus, the successful collaboration between diagnostic imaging and anatomic pathology can represent a fundamental step in the "tortuous" but decisive path towards personalized medicine.

Development of 99mTc-conjugated JS001 antibody for in vivo mapping of PD-1 distribution in murine.

Here we reported the development of a novel immuno-SPECT tracer, namely 99mTc-JS001, to non-invasively image PD-1 expression in mice. The JS001 antibody was directly labeled by the most widely used SPECT radionuclide 99mTc with a radiochemical yield of 90%, and the specific activity was ≤74 GBq/mmol. After the radiolabeling, 99mTc-JS001 exhibited a similar immnuoaffinity to PD-1 in vitro. 99mTc-conjugated JS001 maintained intact in 5% HSA system for 24 h. S180 sarcoma xenograft-bearing Kunming mice and BGC823 gastric cancer orthotopic tumor model were built. Bio-distribution and/or immuno-SPECT studies with 99mTc-JS001 showed the antibody maintained in the blood, liver, kidneys and tumors at 1.5 ID%/g, 1.4 ID%/g, 2.0 ID%/g and 0.5 ID%/g, respectively. Also, there was a higher uptake in the BGC823 orthotopic tumor than that in the adjunct stomach. These results demonstrated that 99mTc-JS001 might have capacity to monitor the PD-1 expression in vivo, which might facilitate the anti-PD-1 antibodies treatment in preclinical models.

Pyeloduodenal fistula diagnosed with technetium-99m scintigraphy and managed with a conservative strategy.

We present a case of pyeloduodenal fistula in an 89-year-old woman with history of nephrolithiasis and recurrent urinary tract infection (UTI) who presented to the emergency department with back pain. CT revealed a malrotated right kidney with a large renal stone and possible fistulous connection between the second portion of the duodenum and the right renal collecting system. Technetium-99m scintigraphy confirmed presence of the fistula. The patient declined intervention and was discharged from the hospital with oral antibiotic suppressive therapy. The patient remained clinically stable at time of follow-up 3 months later. Spontaneous pyeloduodenal fistula is an aetiology of recurrent upper or lower UTIs or persistent bacteriuria though uncommonly recognised. Diagnosis may be achieved using several modalities, including technetium-99m scintigraphy. Nephrectomy and primary fistula closure has traditionally been the treatment of choice for this condition; however, conservative management is an option for patients with intact renal function.

Intercomparison of 99mTc, 18F and 111In activity measurements with radionuclide calibrators in Belgian hospitals.

This study presents current status of performance of radiopharmaceutical activity measurements using radionuclide calibrators in Belgium. An intercomparison exercise was performed among 15 hospitals to test the accuracy of 99mTc, 18F and 111In activity measurements by means of radionuclide calibrators. Four sessions were held in different geographical regions between December 2013 and February 2015. The data set includes measurements from 38 calibrators, yielding 36 calibrations for 99mTc and 111In, and 21 calibrations for 18F. For each radionuclide, 3 ml of stock solution was measured in two clinical geometries: a 10 ml glass vial and a 10 ml syringe. The initial activity was typically 100 MBq for 99mTc, 15 MBq for 111In and 115 MBq for 18F. The reference value for the massic activity of the radioactive solutions was determined by means of primary and secondary standardisation techniques at the radionuclide metrology laboratory of the JRC. The overall results of the intercomparison were satisfactory for 99mTc and 18F, since most radionuclide calibrators (>70%) were accurate within ±5% of the reference value. Nevertheless, some devices underestimated the activity by 10-20%. Conversely, 111In measurements were strongly affected by source geometry effects and this had a negative impact on the accuracy of the measurements, in particular for the syringe sample. Large overestimations (up to 72%) were observed, even when taking into account the corrections and uncertainties supplied by the manufacturers for container effects. The results of this exercise encourage the hospitals to perform corrective actions to improve the calibration of their devices where needed.

Microradiopharmaceutical for Metastatic Melanoma.

PURPOSE: The purpose of this article was to develop, characterize and test (in vivo) dacarbazine microparticles that may be labeled with 99mTc and Ra-223 for both use: diagnostic and therapy of metastatic melanoma. METHODS: We developed by double emulsion solvent evaporation methodology the microparticle. The characterization has been done using, Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). The labeling with 99mTc and Ra-223 has been done by the direct labeling process. Also the formulation has been tested pre-clinically using Balb/c mice inducted with melanoma, performing the the biodistribution and planar imaging. Cytotoxicity evaluation was also done in M3 V cell line. In order to understand the safety aspects of the microparticles, microbiological study (endotoxin and sterility) has been done. Finally, planar imaging was performed to evaluate the diagnosing aspect. RESULTS: The results showed that a 559 nm microparticles was obtained with a spherical shape. The labeling process with 99mTc reached over 90% of efficacy. On the other hand, the labeling process with Ra-223 showed a 70% efficacy. The results in inducted animals demonstrated that the microparticles were able to reach the tumor with a high rate (20%). Also demonstrated a low recognition by the Mononuclear Phagocytic System. The cytotoxicity and the microbiological control, corroborates the safety aspect of these microparticles. CONCLUSION: The planar image and the possible labeling with Ra-223, corroborates the use as a theragnostic agent for imaging and therapy of Metastatic Melanoma.

Molecular radiotheragnostics in thyroid disease.

Molecular radiotheragnostics directly links nuclear medicine diagnostic imaging to therapy. The imaging study is used to detect a specific molecular target associated with a disease process. A radiotherapeutic molecule with a similar biodistribution to the diagnostic agent can then be used to deliver targeted therapy.Molecular radiotheragnostics have been applied to manage both benign and malignant thyroid disease since the 1940s. The specific molecular pathway targeted is the sodium/iodide symporter (NIS) located on the basolateral membrane of the thyroid follicular cell. Radiolabelling of iodide or a similar ion allows targeting of the NIS system with radiopharmaceuticals for imaging (123I-radioiodine and 99mTc-pertechnetate) and treatment (131I-radioiodine) by virtue of their gamma ray and beta-particle emissions, respectively.Scintigraphic imaging directly guides 131I-radioiodine treatment planning to maximise therapeutic benefit while minimising adverse reactions, in a personalised medicine approach.

Targeted tumor SPECT/CT dual mode imaging using multifunctional RGD-modified low generation dendrimer-entrapped gold nanoparticles.

Multifunctional low-generation dendrimer-entrapped gold nanoparticles (Au DENPs) were designed and synthesized. The formed Au DENPs modified with an arginine-glycine-aspartic peptide and labeled with 99mTc possess a uniform size distribution, desirable colloidal stability and biocompatibility, and can be used as a promising nanoprobe for targeted SPECT/CT imaging of αvß3 integrin-expressing tumors.

Gammagrafía hepatobiliar con 99mTc-mebrofenina en una paciente con fístula bilio-pleuro-bronquial / 99mTc-mebrofenin hepatobiliary scintigraphy in a patient with a bilio-pleural-bronchial fistula

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99mTc-radiolabeled GE11-modified peptide for ovarian tumor targeting.

BACKGROUND: Ovarian cancer is a serious threat for women health and the early diagnosis of this cancer might improves the survival rate of patients. The use of the targeted radiopharmaceuticals could be a non-invasive and logical method for tumor imaging. The aim of this study was to radiolabel GE11 peptide as a new specific probe for imaging of ovarian tumor. METHODS: HYNIC-SSS-GE11 peptide was labeled with 99mTc using tricine as a coligand. The 99mTc-tricine-HYNIC-SSS-GE11 peptide was evaluated for specific cellular binding in three cell lines with different levels of EGFR expression. Tumor targeting was assessed in SKOV3 tumor bearing mice. RESULTS: By using tricine as a coligand, labeling yield was more than 98% and the stability of the radiolabelled peptide in human serum up to 4 h was 96%. The in vitro cell uptake test showed that this radiolabeled peptide had a good affinity to SKOV3 cells with dissociation constant of 73 nM. The in vivo results showed a tumor/muscle ratio of 3.2 at 4 h following injection of 99mTc-tricine-HYNIC-SSS-GE11 peptide. CONCLUSIONS: Results of this study showed that 99mTc-tricine-HYNIC-SSS-GE11 peptide could be a promising tool for diagnosis and staging of ovarian cancer. 99mTc-tricine-HYNIC-SSS-GE11, a novl targeted agent for ovarian tumor imaging.

Evaluation of Acridine Orange Derivatives as DNA-Targeted Radiopharmaceuticals for Auger Therapy: Influence of the Radionuclide and Distance to DNA.

A new family of 99mTc(I)- tricarbonyl complexes and 125I-heteroaromatic compounds bearing an acridine orange (AO) DNA targeting unit was evaluated for Auger therapy. Characterization of the DNA interaction, performed with the non-radioactive Re and 127I congeners, confirmed that all compounds act as DNA intercalators. Both classes of compounds induce double strand breaks (DSB) in plasmid DNA but the extent of DNA damage is strongly dependent on the linker between the Auger emitter (99mTc or 125I) and the AO moiety. The in vitro evaluation was complemented with molecular docking studies and Monte Carlo simulations of the energy deposited at the nanometric scale, which corroborated the experimental data. Two of the tested compounds, 125I-C5 and 99mTc-C3, place the corresponding radionuclide at similar distances to DNA and produce comparable DSB yields in plasmid and cellular DNA. These results provide the first evidence that 99mTc can induce DNA damage with similar efficiency to that of 125I, when both are positioned at comparable distances to the double helix. Furthermore, the high nuclear retention of 99mTc-C3 in tumoral cells suggests that 99mTc-labelled AO derivatives are more promising for the design of Auger-emitting radiopharmaceuticals than the 125I-labelled congeners.

Breastdosimetry of 99mTc-balloon in complementary radiotherapy.

Dose reinforcement in primary tumor cavity can complement conventional radiotherapy in patients with early breast cancer. In this study, a dosimetric analysis was conducted by pertechnetate-99mTc-filled balloon brachytherapy (TBB). METHODS: Dosimetry based on radiochromic films and on a computational voxel thorax model was performed. Calibration protocol achieved a mathematical relationship between dose and optical density in films placed on the surface at a distance of 0-9cm, 1cm between them, in which dose values were provided by MCNP® code. Moreover, experimental spatial dose distribution was prepared. A female thorax voxel model was developed in the SISCODES®/MCNP® codes. Additionally, experimental and computational doses at 8-10mm from balloon surface were compared. RESULTS: Dose from 99mTc-balloon, with 16mm diameter, 32.22GBq activity, and 24h exposure time, achieved 8.08±0.42 (Ue) and 8.82±1.76 (Ue) Gy, at a distance of 10mm from the balloon surface for the experimental data and computational modeling, respectively, thus showing nonsignificant difference. The spatial dose distribution in the chest wall, glandular tissue, breast skin, and lung was presented. The dosimetric findings supported the TBB modality presenting a suitable spatial dose distribution in the tumor bed and preserving the adjacent health tissues. CONCLUSION: TBB is a viable adjuvant brachytherapy modality for breast cancer in patients who have an appropriate indication.

Approach to Oligometastatic Prostate Cancer.

Oligometastatic prostate cancer has increasingly been recognized as a unique clinical state with therapeutic implications. It has been proposed that patients with oligometastases may have a more indolent course and that outcome may be further improved with metastasis-directed local ablative therapy. In addition, there are differing schools of thoughts regarding whether oligometastases represent isolated lesions-where targeted therapy may render a patient disease free-or whether they coexist with micrometastases, where targeted therapy in addition to systemic therapy is required for maximal clinical impact. As such, the approach to the patient with oligometastatic prostate cancer requires multidisciplinary consideration, with surgery, radiotherapy, and systemic therapy potentially of benefit either singularly or in combination. Indeed, mounting evidence suggests durable disease-free intervals and, in some cases, possibly cure, may be achieved with such a multimodal strategy. However, selecting patients that may benefit most from treatment of oligometastases is an ongoing challenge. Moreover, with the advent of new, highly sensitive imaging technologies, the spectrum based on CT of the abdomen and pelvis and technetium bone scan of localized to oligometastatic to widespread disease has become increasingly blurred. As such, new MRI- and PET-based modalities require validation. As some clinical guidelines advise against routine prostate-specific antigen screening, the possibility of more men presenting with locally advanced or de novo oligometastatic prostate cancer exists; thus, knowing how best to treat these patients may become more relevant at a population level. Ultimately, the arrival of prospective clinical data and better understanding of biology will hopefully further inform how best to treat men with this disease.