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Purpose The prostate-specific membrane antigen (PSMA) targeted positron-emitting-tomography (PET) tracer 68 Ga-PSMA-11 shows great promise in the detection of prostate cancer. However, 68 Ga has several shortcomings as a radiolabel including short half-life and non-ideal energies, and this has motivated consideration of 18 F-labelled analogs. 18 F-PSMA-1007 was selected among several 18 F-PSMA-ligand candidate compounds because it demonstrated high labelling yields, outstanding tumor uptake and fast, non-urinary background clearance. Here, we describe the properties of 18 F-PSMA-1007 in human volunteers and patients. Methods Radiation dosimetry of 18 F-PSMA-1007 was determined in three healthy volunteers who underwent whole-body PET-scans and concomitant blood and urine sampling. Following this, ten patients with high-risk prostate cancer underwent 18 F-PSMA-1007 PET/CT (1 h and 3 h p.i.) and normal organ biodistribution and tumor uptakes were examined. Eight patients underwent prostatectomy with extended pelvic lymphadenectomy. Uptake in intra-prostatic lesions and lymph node metastases were correlated with final histopathology, including PSMA immunostaining. Results With an effective dose of approximately 4.4–5.5 mSv per 200–250 MBq examination, 18 F-PSMA-1007 behaves similar to other PSMA-PET agents as well as to other 18 F-labelled PET-tracers. In comparison to other PSMA-targeting PET-tracers, 18 F-PSMA-1007 has reduced urinary clearance enabling excellent assessment of the prostate. Similar to 18 F-DCFPyL and with slightly slower clearance kinetics than PSMA-11, favorable tumor-to-background ratios are observed 2–3 h after injection. In eight patients, diagnostic findings were successfully validated by histopathology. 18 F-PSMA-1007 PET/CT detected 18 of 19 lymph node metastases in the pelvis, including nodes as small as 1 mm in diameter. Conclusion 18 F-PSMA-1007 performs at least comparably to 68 Ga-PSMA-11, but its longer half-life combined with its superior energy characteristics and non-urinary excretion overcomes some practical limitations of 68 Ga-labelled PSMA-targeted tracers.

Lutetium-177 [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 improves survival and quality of life in patients with metastatic castration-resistant prostate cancer, but whether it confers a benefit in hormone-sensitive disease is unknown. We aimed to evaluate [177Lu]Lu-PSMA-617 before docetaxel treatment in patients with de-novo high-volume metastatic hormone-sensitive prostate cancer. UpFrontPSMA was an investigator-initiated, multicentre, open-label, randomised, phase 2 trial done at 11 Australian hospitals. Eligible patients had prostate adenocarcinoma without clinically significant neuroendocrine differentiation or small-cell histology, were aged 18 years or older, had less than 4 weeks on androgen deprivation therapy, had an Eastern Cooperative Oncology Group performance status of 0–2, and had high-volume PSMA-avid disease on [68Ga]Ga-PSMA-11 PET-CT with no major discordance on 2-[18F] fluorodeoxyglucose-PET-CT. Patients were randomly assigned (1:1) to the experimental treatment ([177Lu]Lu-PSMA-617 followed 6 weeks later by docetaxel) or standard-of-care treatment (docetaxel alone) using computer-based block randomisation with random block sizes, stratified by disease volume by conventional imaging and duration of androgen deprivation therapy at the time of registration. Neither patients nor investigators were masked to treatment assignment. Patients in the experimental group received two cycles of [177Lu]Lu-PSMA-617 7·5 GBq every 6 weeks intravenously, followed 6 weeks later by six cycles of docetaxel 75 mg/m2 every 3 weeks intravenously, whereas patients in the standard-of-care treatment group received six cycles of docetaxel 75 mg/m2 every 3 weeks intravenously. All patients received continuous androgen deprivation therapy. The primary endpoint was undetectable prostate-specific antigen (≤0·2 ng/mL) at 48 weeks, assessed using a modified intention-to-treat analysis. The trial is registered with ClinicalTrials.gov, NCT04343885. Between May 5, 2020, and April 18, 2023, 130 patients were randomly assigned, 63 (48%) to [177Lu]Lu-PSMA-617 plus docetaxel and 67 (52%) to docetaxel alone. All patients were male and no race or ethnicity data were collected. Median follow-up was 2·5 years (IQR 1·8–3·0). Four patients in the docetaxel alone group withdrew consent after randomisation and no data beyond screening were collected. An additional four patients were not evaluable for the primary endpoint at 48 weeks (two in each group). 25 (41%) of 61 patients (95% CI 30–54) in the [177Lu]Lu-PSMA-617 plus docetaxel group had undetectable PSA at 48 weeks compared with ten (16%) of 61 patients (9–28) in the docetaxel alone group (OR 3·88, 95% CI 1·61–9·38; p=0·0020). The most common grade 3 or 4 treatment-related adverse events were febrile neutropenia (seven [11%] of 63 patients in the [177Lu]Lu-PSMA-617 plus docetaxel group vs six [10%] of 63 patients in the docetaxel alone group) and diarrhoea (four [6%] of 63 patients vs none). Serious adverse events occurred in 16 (25%) patients in the [177Lu]Lu-PSMA-617 plus docetaxel group (none were definitely related to [177Lu]Lu-PSMA-617) and 16 (25%) patients in the docetaxel alone group. No treatment-related deaths occurred. [177Lu]Lu-PSMA-617 followed by docetaxel improved antitumour activity in patients with de-novo high-volume metastatic hormone-sensitive prostate cancer compared with docetaxel alone, without increased toxic effects. Our data potentially support a role for [177Lu]Lu-PSMA-617 in metastatic hormone-sensitive prostate cancer. Prostate Cancer Research Alliance (Movember Foundation and Australian Government Medical Research Future Fund), US Department of Defence Impact Award-Clinical Trials, Endocyte/Advanced Accelerator Applications (a Novartis company), Australian Nuclear Science and Technology Organization, Victorian Cancer Agency, University of Melbourne, and Peter MacCallum Cancer Foundation.

Targeted radionuclide therapy, in which radiopharmaceuticals deliver potent radionuclides to tumours for localized irradiation, has addressed unmet clinical needs and improved outcomes for patients with cancer 1 , 2 , 3 – 4 . A therapeutic radiopharmaceutical must achieve both sustainable tumour targeting and fast clearance from healthy tissue, which remains a major challenge 5 , 6 . A targeted ligation strategy that selectively fixes the radiopharmaceutical to the target protein in the tumour would be an ideal solution. Here we installed a sulfur (VI) fluoride exchange (SuFEx) chemistry-based linker on radiopharmaceuticals to prevent excessively fast tumour clearance. When the engineered radiopharmaceutical binds to the tumour-specific protein, the system undergoes a binding-to-ligation transition and readily conjugates to the tyrosine residues through the ‘click’ SuFEx reaction. The application of this strategy to a fibroblast activation protein (FAP) inhibitor (FAPI) triggered more than 80% covalent binding to the protein and almost no dissociation for six days. In mice, SuFEx-engineered FAPI showed 257% greater tumour uptake than did the original FAPI, and increased tumour retention by 13-fold. The uptake in healthy tissues was rapidly cleared. In a pilot imaging study, this strategy identified more tumour lesions in patients with cancer than did other methods. SuFEx-engineered FAPI also successfully achieved targeted β- and α-radionuclide therapy, causing nearly complete tumour regression in mice. Another SuFEx-engineered radioligand that targets prostate-specific membrane antigen (PSMA) also showed enhanced therapeutic efficacy. Considering the broad scope of proteins that can potentially be ligated to SuFEx warheads, it might be possible to adapt this strategy to other cancer targets. Radiopharmaceuticals engineered with click chemistry to selectively bind to tumour-specific proteins can be used to successfully target tumour cells, boosting the pharmacokinetics of radionuclide therapy and improving tumour regression.

Amino acid infusion (AAI) is a technique used in radiopharmaceutical therapy (RPT) to reduce toxicity in kidney and increase clearance rate of radiopharmaceuticals from body. In this study our aim is to evaluate its effect in personalized RPT considering kidney and salivary glands as dose limiting organs using a multiscale modeling framework. We developed a Physiologically-Based Pharmacokinetic (PBPK) model consisting of 19 compartments, personalized it for four prostate cancer patients using data derived from gamma camera imaging. This model was used to investigate the influence of AAI on the absorbed dose to tumors and organs at risk. We then computed the maximum safe injected activity based on the PBPK model. To address the effects of interstitial fluid pressure (IFP) and tumor heterogeneity, we coupled the PBPK model with convection-diffusion-reaction (CDR) equations. To compare the effectiveness of our modeling approaches, we calculated absorbed doses to the tumors with and without AAI, using both the standalone PBPK model and the coupled PBPK-CDR model. Our findings revealed a relative error (RE) of 9.6% ± 2.2% (mean ± SD) in total tumor absorbed dose calculation between PBPK and CDR equations, attributable to the consideration of IFP. Moreover, AAI proved beneficial for RPT when the kidney was designated as the organ-at-risk. It enabled an increase in radiopharmaceutical injection from 12.3 ± 6.32 MBq (mean ± SD) to 15.45 ± 6.95 MBq (RE: 28.5% ± 15.7%), resulting in a corresponding increase in tumor absorbed dose from 67.8 ± 47.45 Gy to 72.43 ± 51.03 Gy (RE: 8.6% ± 5.4%), while maintaining critical kidney absorbed dose limits. However, this was not observed when the salivary gland was considered the dose-limiting organ. Although, AAI allowed for increased therapeutic injection ranging from 4.22 ± 2.23 MBq to 5.25 ± 3.14 MBq (RE: 19.2% ± 9.9%), it results in a minimal increase in tumor absorbed dose of 0.22 ± 0.04 (RE: 1.4% ± 1.3%). Statistical analysis using the Wilcoxon Signed-Rank Test revealed significant effects of AAI on administered activity and tumor absorbed dose (p-value = 0.007 < 0.05). Finally, a local sensitivity analysis was performed on selected radiation and tumor transportation parameters individually to evaluate their impact on the tumor absorbed dose. In conclusion, selection of organ-at-risk in personalized RPT is critical, as it determines the injected activity amount and the efficacy of delivery-enhancing techniques.

Progressive metastatic castration-resistant prostate cancer is a highly lethal disorder and new effective therapeutic agents that improve patient outcomes are urgently needed. Lutetium-177 [177Lu]-PSMA-617, a radiolabelled small molecule, binds with high affinity to prostate-specific membrane antigen (PSMA) enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer. We aimed to investigate the safety, efficacy, and effect on quality of life of [177Lu]-PSMA-617 in men with metastatic castration-resistant prostate cancer who progressed after standard treatments. In this single-arm, single-centre, phase 2 trial, we recruited men (aged 18 years and older) with metastatic castration-resistant prostate cancer and progressive disease after standard treatments, including taxane-based chemotherapy and second-generation anti-androgens, from the Peter MacCallum Cancer Centre, Melbourne, VIC, Australia. Patients underwent a screening PSMA and FDG-PET/CT to confirm high PSMA-expression. Eligible patients had progressive disease defined by imaging (according to Response Evaluation Criteria In Solid Tumours [RECIST] or bone scan) or new pain in an area of radiographically evident disease, and were required to have an Eastern Cooperative Oncology Group (ECOG) performance status score of 2 or lower. Eligible patients received up to four cycles of intravenous [177Lu]-PSMA-617, at six weekly intervals. The primary endpoint was PSA response according to Prostate Cancer Clinical Trial Working Group criteria defined as a greater than 50% PSA decline from baseline and toxicity according to CTCAE. Additional primary endpoints were imaging responses (as measured by bone scan, CT, PSMA, and FDG PET/CT) and quality of life (assessed with the EORTC-Q30 and Brief Pain Inventory-Short Form questionnaires), all measured up to 3 months post completion of treatment. This trial is registered with the Australian New Zealand Clinical Trials Registry, number 12615000912583. Between Aug 26, 2015, and Dec 8, 2016, 43 men were screened to identify 30 patients eligible for treatment. 26 (87%) had received at least one line of previous chemotherapy (80% docetaxel and 47% cabazitaxel) and 25 (83%) received prior abiraterone acetate, enzalutamide, or both. The mean administered radioactivity was 7·5 GBq per cycle. 17 (57%) of 30 patients (95% CI 37–75) achieved a PSA decline of 50% or more. There were no treatment-related deaths. The most common toxic effects related to [177Lu]-PSMA-617 were grade 1 dry mouth recorded in 26 (87%) patients, grade 1 and 2 transient nausea in 15 (50%), and G1–2 fatigue in 15 (50%). Grade 3 or 4 thrombocytopenia possibly attributed to [177Lu]-PSMA-617 occurred in four (13%) patients. Objective response in nodal or visceral disease was reported in 14 (82%) of 17 patients with measurable disease. Clinically meaningful improvements in pain severity and interference scores were recorded at all timepoints. 11 (37%) patients experienced a ten point or more improvement in global health score by the second cycle of treatment. Our findings show that radionuclide treatment with [177Lu]-PSMA-617 has high response rates, low toxic effects, and reduction of pain in men with metastatic castration-resistant prostate cancer who have progressed after conventional treatments. This evidence supports the need for randomised controlled trials to further assess efficacy compared with current standards of care. None.

There are currently no standard first-line treatment options for patients with higher grade 2–3, well-differentiated, advanced, gastroenteropancreatic neuroendocrine tumours. We aimed to investigate the efficacy and safety of first-line [177Lu]Lu-DOTA-TATE (177Lu-Dotatate) treatment. NETTER-2 was an open-label, randomised, parallel-group, superiority, phase 3 trial. We enrolled patients (aged ≥15 years) with newly diagnosed higher grade 2 (Ki67 ≥10% and ≤20%) and grade 3 (Ki67 >20% and ≤55%), somatostatin receptor-positive (in all target lesions), advanced gastroenteropancreatic neuroendocrine tumours from 45 centres across nine countries in North America, Europe, and Asia. We used interactive response technologies to randomly assign (2:1) patients to receive four cycles (cycle interval was 8 weeks ± 1 week) of intravenous 177Lu-Dotatate plus intramuscular octreotide 30 mg long-acting repeatable (LAR) then octreotide 30 mg LAR every 4 weeks (177Lu-Dotatate group) or high-dose octreotide 60 mg LAR every 4 weeks (control group), stratified by neuroendocrine tumour grade (2 vs 3) and origin (pancreas vs other). Tumour assessments were done at baseline, week 16, and week 24, and then every 12 weeks until disease progression or death. The primary endpoint was progression-free survival by blinded, independent, central radiology assessment. We did the primary analysis at 101 progression-free survival events as the final progression-free survival analysis. NETTER-2 is registered with ClinicalTrials.gov, NCT03972488, and is active and not recruiting. Between Jan 22, 2020, and Oct 13, 2022, we screened 261 patients, 35 (13%) of whom were excluded. We randomly assigned 226 (87%) patients (121 [54%] male and 105 [46%] female) to the 177Lu-Dotatate group (n=151 [67%]) and control group (n=75 [33%]). Median progression-free survival was 8·5 months (95% CI 7·7–13·8) in the control group and 22·8 months (19·4–not estimated) in the 177Lu-Dotatate group (stratified hazard ratio 0·276 [0·182–0·418]; p<0·0001). During the treatment period, adverse events (of any grade) occurred in 136 (93%) of 147 treated patients in the 177Lu-Dotatate group and 69 (95%) of 73 treated patients in the control group. There were no study drug-related deaths during the treatment period. First-line 177Lu-Dotatate plus octreotide LAR significantly extended median progression-free survival (by 14 months) in patients with grade 2 or 3 advanced gastroenteropancreatic neuroendocrine tumours. 177Lu-Dotatate should be considered a new standard of care in first-line therapy in this population. Advanced Accelerator Applications, a Novartis Company.

Purpose Prostate-specific membrane antigen (PSMA) is a promising target for diagnosis and radioligand therapy (RLT) of prostate cancer. Two novel PSMA-targeting radionuclide therapy agents, [ 177 Lu]Lu-P17-087, and its albumin binder modified derivative, [ 177 Lu]Lu-P17-088, were evaluated in metastatic castration-resistant prostate cancer (mCRPC) patients. The primary endpoint was dosimetry evaluation, the second endpoint was radiation toxicity assessment (CTCAE 5.0) and PSA response (PCWG3). Methods Patients with PSMA-positive tumors were enrolled after [ 68 Ga]Ga-PSMA-11 PET/CT scan. Five mCRPC patients received [ 177 Lu]Lu-P17-087 and four other patients received [ 177 Lu]Lu-P17-088 (1.2 GBq/patient). Multiple whole body planar scintigraphy was performed at 1.5, 4, 24, 48, 72, 120 and 168 h after injection and one SPECT/CT imaging was performed at 24 h post-injection for each patient. Dosimetry evaluation was compared in both patient groups. Results Patients showed no major clinical side-effects under this low dose treatment. As expected [ 177 Lu]Lu-P17-088 with longer blood circulation (due to its albumin binding) exhibited higher effective doses than [ 177 Lu]Lu-P17-087 (0.151 ± 0.036 vs. 0.056 ± 0.019 mGy/MBq, P  = 0.001). Similarly, red marrow received 0.119 ± 0.068 and 0.048 ± 0.020 mGy/MBq, while kidney doses were 0.119 ± 0.068 and 0.046 ± 0.022 mGy/MBq, respectively. [ 177 Lu]Lu-P17-087 demonstrated excellent tumor uptake and faster kinetics; while [ 177 Lu]Lu-P17-088 displayed a slower washout and higher average dose (7.75 ± 4.18 vs. 4.72 ± 2.29 mGy/MBq, P  = 0.018). After administration of [ 177 Lu]Lu-P17-087 and [ 177 Lu]Lu-P17-088, 3/5 and 3/4 patients showed reducing PSA values, respectively. Conclusion [ 177 Lu]Lu-P17-088 and [ 177 Lu]Lu-P17-087 displayed different pharmacokinetics but excellent PSMA-targeting dose delivery in mCRPC patients. These two agents are promising RLT agents for personalized treatment of mCRPC. Further studies with increased dose and frequency of RLT are warranted to evaluate the potential therapeutic efficacy. Trial registration 177 Lu-P17-087/ 177 Lu-P17-088 in Patients with Metastatic Castration-resistant Prostate Cancer (NCT05603559, Registered at 25 October, 2022). URL of registry https://classic.clinicaltrials.gov/ct2/show/NCT05603559 .

Ra, an alpha-emitting radionuclide with a half-life of 3.63 d, holds significant promise in cancer therapy. However, like many other medical alpha-emitters, the development of Ra radiopharmaceuticals has long been impeded by dosimetry limitation caused by the off-target toxicity, which is tightly related to the secondary radioactivity biodistribution. In this work, we propose leveraging radionuclide trap preorganized in nanoscale barium-based metal-organic framework (AEMOF-6) to overcome the off-target effects of Ra therapy. Functional side chains with high binding affinity towards Ra and its decay daughters were preinstalled inside the cavity of nanoscale AEMOF-6, constructing radionuclide trap capable of inhibiting the radioactivity leaking effectively. The Ra-labeled radiopharmaceutical Ra-AEMOF-6@CS demonstrates effective radioactivity localization ability, significant antitumor efficacy, and favorable biosafety. It was obtained with a radiochemical yield of 92.87% and a radiochemical purity of 94.75%, maintaining over 87% stability throughout the observation period. Integrated micro-PET/CT and micro-SPECT/CT imaging, complemented by biodistribution analyses, validated the robust stability and radioactivity localization capability of the AEMOF-6@CS nanocarrier . A dose-dependent antitumor effect accompanied by excellent biosafety was observed, achieving complete tumor eradication in 20%, 40%, and 60% of mice at 36 d after injection of 18.5, 37.0, and 55.5 kBq of Ra-AEMOF-6@CS, respectively. This discovery provides a potential approach to address the challenges of radioactivity migration of Ra radiopharmaceuticals radionuclide trap preorganized in nanoscale MOFs, which can also be beneficial to other alpha-emitting radiopharmaceuticals.

The brain's energy budget can be non-invasively assessed with different imaging modalities such as functional MRI (fMRI) and PET (fPET), which are sensitive to oxygen and glucose demands, respectively. The introduction of hybrid PET/MRI systems further enables the simultaneous acquisition of these parameters. Although a recently developed method offers the quantification of task-specific changes in glucose metabolism (CMRGlu) in a single measurement, direct comparison of the two imaging modalities is still difficult because of the different temporal resolutions. Thus, we optimized the protocol and systematically assessed shortened task durations of fPET to approach that of fMRI. Twenty healthy subjects (9 male) underwent one measurement on a hybrid PET/MRI scanner. During the scan, tasks were completed in four blocks for fMRI (4 × 30 s blocks) and fPET: participants tapped the fingers of their right hand repeatedly to the thumb while watching videos of landscapes. For fPET, subjects were randomly assigned to groups of n = 5 with varying task durations of 10, 5, 2 and 1 min, where task durations were kept constant within a measurement. The radiolabeled glucose analogue [18F]FDG was administered as 20% bolus plus constant infusion. The bolus increases the signal-to-noise ratio and leaves sufficient activity to detect task-related effects but poses additional challenges due to a discontinuity in the tracer uptake. First, three approaches to remove task effects from the baseline term were evaluated: (1) multimodal, based on the individual fMRI analysis, (2) atlas-based by removing presumably activated regions and (3) model-based by fitting the baseline with exponential functions. Second, we investigated the need to capture the arterial input function peak with automatic blood sampling for the quantification of CMRGlu. We finally compared the task-specific activation obtained from fPET and fMRI qualitatively and statistically. CMRGlu quantified only with manual arterial samples showed a strong correlation to that obtained with automatic sampling (r = 0.9996). The multimodal baseline definition was superior to the other tested approaches in terms of residuals (p < 0.001). Significant task-specific changes in CMRGlu were found in the primary visual and motor cortices (tM1 = 18.7 and tV1 = 18.3). Significant changes of fMRI activation were found in the same areas (tM1 = 16.0 and tV1 = 17.6) but additionally in the supplementary motor area, ipsilateral motor cortex and secondary visual cortex. Post-hoc t-tests showed strongest effects for task durations of 5 and 2 min (all p < 0.05 FWE corrected), whereas 1 min exhibited pronounced unspecific activation. Percent signal change (PSC) was higher for CMRGlu (∼18%–27%) compared to fMRI (∼2%). No significant association between PSC of task-specific CMRGlu and fMRI was found (r = 0.26). Using a bolus plus constant infusion protocol, the necessary task duration for reliable quantification of task-specific CMRGlu could be reduced to 5 and 2 min, therefore, approaching that of fMRI. Important for valid quantification is a correct baseline definition, which was ideal when task-relevant voxels were determined with fMRI. The absence of a correlation and the different activation pattern between fPET and fMRI suggest that glucose metabolism and oxygen demand capture complementary aspects of energy demands. •Quantification of task-specific CMRGlu with 20% bolus plus constant infusion.•Functional PET task durations down to 1 min were evaluated.•Active primary regions overlap between BOLD and CMRGlu.•No significant correlation between BOLD and CMRGlu.

PurposeThis translational study is designed to assess the safety, dosimetry and therapeutic response to a single, low-dose of 177Lu-EB-PSMA-617 in comparison to 177Lu-PSMA-617 in patients with mCRPC.MethodsFollowing institutional review board approval and informed consent, nine patients with mCRPC were recruited. Four patients accepted intravenous injection of 0.80–1.1 GBq (21.5–30 mCi) of 177Lu-EB-PSMA-617, then underwent serial whole-body planar and SPECT/CT imaging at 2, 24, 72, 120 and 168 h. The other five patients accepted intravenous injection of 1.30–1.42 GBq (35–38.4 mCi) 177Lu-PSMA-617, then underwent the same imaging procedures at 0.5, 2, 24, 48, and 72 h. All patients were evaluated by 68Ga-PSMA-617 PET/CT before and one month after the treatment. Dosimetry evaluation was compared in both patient groups.ResultsWhen the bone metastasis tumors with comparable baseline SUVmax in the range of 10.0–15.0 were selected from the two groups for comparison, the accumulated radioactivity of 177Lu-EB-PSMA-617 was about 3.02-fold higher than that of 177Lu-PSMA-617. Imaging dose of 177Lu-EB-PSMA-617 treatment showed significant decrease of 68Ga-PSMA-617 uptake within a month, which was not observed in patients imaged with 177Lu-PSMA-617 (SUV change: −32.43 ± 0.14% vs. 0.21 ± 0.37%; P = 0.002). 177Lu-EB-PSMA-617 also had higher absorbed doses in the red bone marrow and kidneys than 177Lu-PSMA-617 (0.0547 ± 0.0062 vs. 0.0084 ± 0.0057 mSv/MBq for red bone marrow, P < 0.01; 2.39 ± 0.69 vs. 0.39 ± 0.06 mSv/MBq for kidneys, P < 0.01).ConclusionThis first-in-human study demonstrated that 177Lu-EB-PSMA-617 had higher accumulation in mCRPC and that low imaging dose appears to be effective in treating tumors with high 68Ga-PSMA-617 uptakes. Elevated uptakes of 177Lu-EB-PSMA-617 in kidneys and red bone marrow were well tolerated at the administered low dose. Further investigations with increased dose and frequency of administration are warranted.