Dosimetry of 177Lu-PSMA-617 for the treatment of metastatic castration-resistant prostate cancer: A sub-study of the VISION trial.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. TPS265-TPS265 ◽  
Author(s):  
Jens Kurth ◽  
Ken Herrmann ◽  
Matthias Eiber ◽  
Kambiz Rahbar ◽  
Martin Heuschkel ◽  
...  

TPS265 Background: Prostate-specific membrane antigen-617 labelled with lutetium-177 (177Lu-PSMA-617) is a promising treatment for patients with metastatic castration-resistant prostate cancer (mCRPC) after treatment with taxane chemotherapy and a novel androgen axis inhibitor. The radiotherapeutic molecule has high PSMA binding affinity, prolonged tumor retention with a rapid kidney clearance, and high tumor-to-background ratio, delivering therapeutically relevant doses of radiation to prostate cancer lesions. A randomized, prospective phase 3 trial to assess the efficacy of 177Lu-PSMA-617 in patients with progressive PSMA-positive mCRPC is ongoing (VISION trial, NCT03511664). However, as with other targeted radionuclide treatment modalities, there may be a risk of radiotoxicity to normal organs. Therefore, estimation of absorbed doses in these organs in a representative manner within the framework of such a study is essential. Methods: As a substudy of the VISION trial, extensive intratherapeutic dosimetry will be performed in a group of 30 patients at four participating German sites. Patients will undergo planar whole-body scintigraphy scans and single-photon emission computed tomography/computerized tomography (SPECT/CT) scans of the upper and lower abdomen at approximately 2, 24, and 48 hours, and 7 days after administration, along with blood sampling and urine collection. SPECT/CT data will be quantitatively reconstructed and a standardized calibration procedure of the imaging and measurement equipment used (SPECT/CT, dose calibrator, well counter) will be performed at all sites according to European Association of Nuclear Medicine (EANM) and Medical International Radiation Dose (MIRD) guidelines [1]. Organ masses will be measured for each patient using CT imaging, if accessible. Absorbed doses for kidneys, liver, spleen, salivary and lacrimal glands, and bone marrow, as well as prostate cancer lesions, will be calculated for each patient following international guidelines [2,3]. References: [1] Ljungberg M et al. J Nucl Med 2016;57:151–62. [2] Siegel JA et al. J Nucl Med 1999;40:37S–61S. [3] Hindorf C et al. Eur J Nucl Med Mol Imaging 2010;37:1238–50. Clinical trial information: NCT03511664.

Author(s):  
Jinguo Zhang ◽  
Guanzhong Zhai ◽  
Bin Yang ◽  
Zhenhe Liu

Prostate cancer is one of the most common cancers in men. This cancer is often associated with indolent tumors with little or no lethal potential. Some of the patients with aggressive prostate cancer have increased morbidity and early deaths. A major complication in advanced prostate cancer is bone metastasis that mainly results in pain, pathological fractures, and compression of spinal nerves. These complications in turn cause severe pain radiating to the extremities and possibly sensory as well as motor disturbances. Further, in patients with a high risk of metastases, treatment is limited to palliative therapies. Therefore, accurate methods for the detection of bone metastases are essential. Technical advances such as single-photon emission computed tomography/ computed tomography (SPECT/CT) have emerged after the introduction of bone scans. These advanced methods allow tomographic image acquisition and help in attenuation correction with anatomical co-localization. The use of positron emission tomography/CT (PET/CT) scanners is also on the rise. These PET scanners are mainly utilized with 18F-sodium-fluoride (NaF), in order to visualize the skeleton and possible changes. Moreover, NaF PET/CT is associated with higher tracer uptake, increased target-to-background ratio and has a higher spatial resolution. However, these newer technologies have not been adopted in clinical guidelines due to lack of definite evidence in support of their use in bone metastases cases. The present review article is focused on current perspectives and challenges of computerized tomography (CT) applications in cases of bone metastases during prostate cancer.


2021 ◽  
Vol 14 (5) ◽  
pp. 385
Author(s):  
Leonardo L. Fuscaldi ◽  
Danielle V. Sobral ◽  
Ana Claudia R. Durante ◽  
Fernanda F. Mendonça ◽  
Ana Cláudia C. Miranda ◽  
...  

Prostate-specific membrane antigen (PSMA) is a glycoprotein present in the prostate, that is overexpressed in prostate cancer (PCa). Recently, PSMA-directed radiopharmaceuticals have been developed, allowing the pinpointing of tumors with the Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) imaging techniques. The aim of the present work was to standardize and validate an automatic synthesis module-based radiolabeling protocol for [68Ga]Ga-PSMA-11, as well as to produce a radiopharmaceutical for PET imaging of PCa malignancies. [68Ga]Ga-PSMA-11 was evaluated to determine the radiochemical purity (RCP), stability in saline solution and serum, lipophilicity, affinity to serum proteins, binding and internalization to lymph node carcinoma of the prostate (LNCaP) cells, and ex vivo biodistribution in mice. The radiopharmaceutical was produced with an RCP of 99.06 ± 0.10%, which was assessed with reversed-phase high-performance liquid chromatography (RP-HPLC). The product was stable in saline solution for up to 4 h (RCP > 98%) and in serum for up to 1 h (RCP > 95%). The lipophilicity was determined as −3.80 ± 0.15, while the serum protein binding (SPB) was <17%. The percentages of binding to LNCaP cells were 4.07 ± 0.51% (30 min) and 4.56 ± 0.46% (60 min), while 19.22 ± 2.73% (30 min) and 16.85 ± 1.34% (60 min) of bound material was internalized. High accumulation of [68Ga]Ga-PSMA-11 was observed in the kidneys, spleen, and tumor, with a tumor-to-contralateral-muscle ratio of >8.5 and a tumor-to-blood ratio of >3.5. In conclusion, an automatic synthesis module-based radiolabeling protocol for [68Ga]Ga-PSMA-11 was standardized and the product was evaluated, thus verifying its characteristics for PET imaging of PCa tumors in a clinical environment.


Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 428
Author(s):  
Friederike Völter ◽  
Lena Mittlmeier ◽  
Astrid Gosewisch ◽  
Julia Brosch-Lenz ◽  
Franz Josef Gildehaus ◽  
...  

Background: Dosimetry can tailor prostate-specific membrane-antigen-targeted radioligand therapy (PSMA-RLT) for metastatic castration-resistant prostate cancer (mCRPC). However, whole-body tumor dosimetry is challenging in patients with a high tumor burden. We evaluate a simplified index-lesion-based single-photon emission computed tomography (SPECT) dosimetry method in correlation with clinical outcome. Methods: 30 mCRPC patients were included (median 71 years). The dosimetry was performed for the first cycle using quantitative 177Lu-SPECT. The response was evaluated using RECIST 1.1 and PERCIST criteria, as well as changes in PSMA-positive tumor volume (PSMA-TV) in post-therapy PSMA-PET and biochemical response according to PSA changes after two RLT cycles. Results: Mean tumor doses as well as index-lesion doses were significantly higher in PERCIST responders compared to non-responders (10.2 ± 12.0 Gy/GBq vs. 4.0 ± 2.9 Gy/GBq, p = 0.03 and 13.7 ± 14.2 Gy/GBq vs. 5.9 ± 4.4 Gy/GBq, p = 0.04, respectively). No significant differences in mean tumor and index lesion doses were observed between responders and non-responders according to RECIST 1.1, PSMA-TV, and biochemical response criteria. Conclusion: Compared to mean tumor doses on a patient level, single index-lesion-based SPECT dosimetry correlates equally well with the response to PSMA-RLT according to PERCIST criteria and may represent a fast and feasible dosimetry approach for clinical routine.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2938
Author(s):  
Liam Widjaja ◽  
Rudolf A. Werner ◽  
Tobias L. Ross ◽  
Frank M. Bengel ◽  
Thorsten Derlin

177Lu-Prostate-specific membrane antigen (PSMA)-radioligand therapy (RLT) is a promising treatment option in patients with metastatic castration-resistant prostate cancer (mCRPC). We aimed to determine the predictive value of pretherapeutic PSMA-ligand positron emission tomography (PET) and established clinical parameters for early biochemical response after two cycles of RLT. In total, 71 mCRPC patients who had undergone PET/computed tomography (CT) with 68Ga-PSMA-11 prior to two cycles of 177Lu-PSMA-617 RLT were included. Malignant lesions on pretherapeutic PET/CTs were manually segmented and average maximum PSMA expression (maximum standardized uptake values, SUVmax), whole-body PSMA-tumor volume (TV), and whole-body total lesion (TL)-PSMA were calculated. We then tested the predictive performance of these parameters for early biochemical response (defined as prostate-sepcific antigen (PSA) decrease of ≥50% according to PCWG2) after two cycles of RLT, relative to established clinical parameters. Early PSA response was observed in 34/71 patients. PSA change after two cycles of RLT correlated with pretherapeutic SUVmax (r = −0.49; p < 0.001), but not with PSMA-TV (r = 0.02; p = 0.89) or TL-PSMA (r = −0.15; p = 0.22). A cut-off of 19.8 for SUVmax and 75.5 years for age was defined by receiver operating characteristics and revealed a significant outcome difference for early biochemical response between patients with adversely low vs. high PSMA expression and low vs. high age (p < 0.001). Multivariate analysis identified SUVmax (HR, 7.94, p = 0.001) and age (HR, 8.05, p = 0.002) as independent predictors for PSA response early in the treatment course. Thus, high age and high PSMA expression in patients scheduled for RLT identify patients with early biochemical response. This study provides a rationale for further prospective studies exploring PET-guided treatment intensification in selected patients.


Author(s):  
Vasko Kramer ◽  
René Fernández ◽  
Wencke Lehnert ◽  
Luis David Jiménez-Franco ◽  
Cristian Soza-Ried ◽  
...  

Abstract Introduction PSMA-targeted radionuclide therapy with lutetium-177 has emerged as an effective treatment option for metastatic, castration-resistant prostate cancer (mCRPC). Recently, the concept of modifying PSMA radioligands with an albumin-binding entity was demonstrated as a promising measure to increase the tumor uptake in preclinical experiments. The aim of this study was to translate the concept to a clinical setting and evaluate the safety and dosimetry of [177Lu]Lu-PSMA-ALB-56, a novel PSMA radioligand with albumin-binding properties. Methods Ten patients (71.8 ± 8.2 years) with mCRPC received an activity of 3360 ± 393 MBq (120–160 μg) [177Lu]Lu-PSMA-ALB-56 followed by whole-body SPECT/CT imaging over 7 days. Volumes of interest were defined on the SPECT/CT images for dosimetric evaluation for healthy tissue and tumor lesions. General safety and therapeutic efficacy were assessed by measuring blood biomarkers. Results [177Lu]Lu-PSMA-ALB-56 was well tolerated, and no severe adverse events were observed. SPECT images revealed longer circulation of [177Lu]Lu-PSMA-ALB-56 in the blood with the highest uptake in tumor lesions at 48 h post injection. Compared with published data for other therapeutic PSMA radioligands (e.g. PSMA-617 and PSMA I&T), normalized absorbed doses of [177Lu]Lu-PSMA-ALB-56 were up to 2.3-fold higher in tumor lesions (6.64 ± 6.92 Gy/GBq) and similar in salivary glands (0.87 ± 0.43 Gy/GBq). Doses to the kidneys and red marrow (2.54 ± 0.94 Gy/GBq and 0.29 ± 0.07 Gy/GBq, respectively) were increased. Conclusion Our data demonstrated that the concept of albumin-binding PSMA-radioligands is feasible and leads to increased tumor doses. After further optimization of the ligand design, the therapeutic outcomes may be improved for patients with prostate cancer.


2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hideyuki Akaza ◽  
Giuseppe Procopio ◽  
Choosak Pripatnanont ◽  
Gaetano Facchini ◽  
Sergio Fava ◽  
...  

Purpose There is a major clinical need to devise an optimal treatment sequence for the multiple therapy options available for patients with metastatic castration-resistant prostate cancer (mCRPC). In the absence of prospective clinical trials, sequencing information can be derived from large, real-world registry studies. Patients and Methods PROXIMA (Treatment Patterns in Patients With Metastatic Castration-Resistant Prostate Cancer Previously Treated With Docetaxel-Based Chemotherapy) is a large, global, prospective registry study evaluating real-world treatment patterns of patients with mCRPC who experience disease progression during or after docetaxel therapy. Patients were enrolled worldwide between 2011 and 2014. Treatments were determined by the treating physicians and recorded in categories of chemotherapy, hormonal therapy, targeted therapy, immunotherapy, and palliative therapy. Treatment sequencing patterns, response to treatment, and types of progression were recorded and analyzed. Progression-free survival and overall survival with different treatment modalities were analyzed using Kaplan–Meier method. Results Treatment patterns were evaluated in 903 patients. Therapy selection was influenced by region. Hormonal therapy (57.5%) and taxane chemotherapy (26.4%) were the most frequently administered first subsequent treatments after docetaxel. Tumor responses to first subsequent treatment were observed in 22.6% of evaluable patients. Overall survival and progression-free survival did not differ significantly across different treatment modalities. Conclusion Identifying an optimal treatment sequence is vital for improving the care of patients with mCRPC. The PROXIMA registry provided a representative sample of global data on real-world treatment patterns for patients with mCRPC previously treated with docetaxel. These data can be used to devise optimal therapy sequences and inform treatment decisions.


2019 ◽  
Vol 12 (4) ◽  
pp. e227910
Author(s):  
Kanhaiyalal Agrawal ◽  
P Sai Sradha Patro ◽  
C Preetam

There is literature evidence showing utility of somatostatin receptor (SSTR) positron emission tomography-CT (PET-CT) imaging in differentiated thyroid cancer with Thyroglobulin Elevated and Negative Iodine Scan (TENIS). These patients are less benefited with I-131 therapy and surgery remains only curable option if disease could be localised. If surgery is not feasible, other therapeutic options are not promising. However, if these patients show strongly positive SSTR imaging, then possibility of peptide receptor radionuclide therapy may be explored. As SSTR PET-CT imaging is expensive and not widely available, Technetium-99m (Tc-99m) hydrazinonicotinyl-Tyr3-octreotide (HYNIC-TOC), which is a Single photon emission computed tomography (SPECT) tracer, can be used. We are documenting a case of raised serum thyroglobulin antibody and negative I-131 whole body scan with disease recurrence localised on Tc-99m HYNIC-TOC scan.


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