Unlabelled: 16 beta-fluoro-5 alpha-dihydrotestosterone (FDHT) is a promising new PET radiopharmaceutical for the imaging of prostate cancer. A recent clinical trial provided the opportunity for refinement of normal-tissue radiation-absorbed dose estimates based on quantitative PET. The objective of the current study was to derive estimates of normal-tissue absorbed doses for (18)F-FDHT administered to patients with advanced prostate cancer.
Methods: Absorbed dose estimates were derived from 10 (18)F-FDHT PET studies (administered activity, 111-407 MBq) of 7 prostate cancer patients. Activity concentrations in plasma and red marrow (assuming a plasmacrit of 0.58, an extracellular fluid fraction of 0.40, and equilibration of activity between plasma and marrow extracellular fluid) were measured ex vivo from a peripheral blood sample. Liver, spleen, urinary bladder contents, and total-body activities were measured by region-of-interest analysis of quantitative whole-body studies acquired with a dedicated PET scanner. Total organ activities and residence times were calculated from the respective PET scan-derived activity concentrations assuming standard (70 kg) man organ masses. Urinary excretion was corrected for hepatobiliary excretion (liver activity), and a first-order adjustment was made for the bladder-wall mass based on the patient's total-body mass. Mean organ absorbed doses were calculated with the MIRD formalism and the standard man model using the MIRDOSE3 software program.
Results: The absorbed doses (mean +/- SD) ranged from 0.00057 +/- 0.000281 cGy/MBq (to skin) to 0.00868 +/- 0.00481 cGy/MBq (to bladder wall) (voiding intervals, 1-2 h), and the effective dose equivalent was 0.00177 +/- 0.000152 cSv/MBq.
Conclusion: The maximum absorbed dose among all tissues in all 10 studies, 0.0151 cGy/MBq, occurred for the urinary bladder wall (with hydration and 1- to 2-h voiding intervals). To ensure that the maximum normal-tissue absorbed dose is kept below the recommended maximum permissible dose of 5 cGy per single administration, a maximum administered activity of 331 MBq (5 cGy/[0.0151 cGy/MBq]) is recommended for (18)F-FDHT.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
More micrometastases, more recurrence? The role of qPCR of PSA mRNA in lymph nodes during prostatectomy.
World J Urol
January 2025
Department of Urology, Urooncology, Robot-assisted and Focal Therapy, University Hospital Magdeburg, Otto-von Guericke University Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany.
Background And Objectives: Radical prostatectomy is a standard treatment for prostate cancer, yet about 30% of patients experience rising biochemical markers within a decade post-surgery. Pelvic lymph node sampling during prostatectomy assesses potential lymph node metastases, but standard histological assessments, which typically examine only 2-3 tissue sections, often miss occult metastases. This study assesses the effectiveness of qPCR in detecting PSA coding KLK3 mRNA for identifying lymph node metastases post-prostatectomy and explores the correlation between PSA-mRNA and biochemical recurrence.
View Article and Find Full Text PDFUnsupervised self-organising map classification of Raman spectra from prostate cell lines uncovers substratified prostate cancer disease states.
Sci Rep
January 2025
School of Physics, Engineering and Technology, University of York, Heslington, York, YO10 5DD, UK.
Prostate cancer is a disease which poses an interesting clinical question: Should it be treated? Only a small subset of prostate cancers are aggressive and require removal and treatment to prevent metastatic spread. However, conventional diagnostics remain challenged to risk-stratify such patients; hence, new methods of approach to biomolecularly sub-classify the disease are needed. Here we use an unsupervised self-organising map approach to analyse live-cell Raman spectroscopy data obtained from prostate cell-lines; our aim is to exemplify this method to sub-stratify, at the single-cell-level, the cancer disease state using high-dimensional datasets with minimal preprocessing.
View Article and Find Full Text PDFCXCL14 in prostate cancer: complex interactions in the tumor microenvironment and future prospects.
J Transl Med
January 2025
Department of Urology, The First Affiliated Hospital of Soochow University, No. 899 Pinghai Road, Suzhou, 215006, People's Republic of China.
CXCL14 is a highly conserved chemokine expressed in various cell types, playing crucial roles in both physiological and pathological processes, including immune regulation and tumorigenesis. Recently, the role of CXCL14 in tumors has attracted considerable attention. However, previous pan-cancer studies have reported inconsistencies regarding the effects of CXCL14 on tumors, particularly concerning its expression levels in tumor tissues and its influence on various phenotypes of cancer cells.
View Article and Find Full Text PDFPrognostic Value of Response Evaluation Using PSMA PET/CT in Patients with Metastatic Prostate Cancer (RECIP 1.0): A Systematic Review and Meta-analysis.
Acad Radiol
January 2025
University Medical Imaging Toronto, Joint Department of Medical Imaging, University Health Network-Sinai Health System -Women's College Hospital, University of Toronto, Toronto, ON, Canada (S.A.M., P.V.H., U.M., A.B.D.). Electronic address:
Rationale And Objectives: Recently, the Response Evaluation Using PSMA PET/CT in Patients with Metastatic Castration-Resistant Prostate Cancer (RECIP 1.0) was proposed to better evaluate treatment response in prostate cancer patients using PET/CT with prostate-specific membrane antigen (PSMA) than more traditional approaches like metabolic PET evaluation response criteria in solid tumor (PERCIST 1.0).
View Article and Find Full Text PDFEarly outcomes following local salvage treatment with MRI-assisted low-dose rate brachytherapy (MARS) for MRI-visible postsurgical bed recurrences and focal intraprostatic recurrences.
Brachytherapy
January 2025
Department of Genitourinary Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX.
Background: To determine outcomes of MRI-assisted radiosurgery (MARS) for salvage brachytherapy using the radioisotope Pd after various upfront treatments including surgery, external beam radiotherapy, and brachytherapy.
Methods: We retrospectively reviewed data for patients who underwent salvage MARS for intraprostatic lesions or prostate bed recurrences from 2016 to 2022. Biochemical recurrence, prostate cancer-specific, and overall survival, and the cumulative incidences of toxicities, were determined by Kaplan-Meier estimates.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!