Low-Count Quantitative SPECT for Men Treated With Radium-223

Not Applicable

Not yet recruiting

• Conditions: Prostate Cancer; Cancer of the Prostate

• Registration Number: NCT07221825
• Lead Sponsor: Washington University School of Medicine

Brief Summary

Internal radiotherapies (radiolabeled molecules that are systemically administered and localize to sites of disease) provide cancer-ablating doses to diseased cells while sparing adjacent normal tissues. \[223Ra\]RaCl2 (Xofigo) is the first FDA-approved alpha-particle emitting radiopharmaceutical therapy (αRPT), providing a survival benefit for men with bone metastatic castration-resistant prostate cancer. Systemically administered radiotherapies distribute throughout the patient, accumulating to unknown levels at sites of disease and in radiosensitive vital organs. The whole-body distribution means that absorbed doses in the patient extend far beyond a pre-defined treatment field. There is a lack of information about αRPT distribution and localization, and this confounds treatment monitoring, complicates dose and schedule personalization, and impedes drug development.

Single-photon emission computed tomography (SPECT) imaging offers a mechanism to quantify uptake; however, αRPT administered activities are significantly lower than those used with diagnostic procedures, which presents a challenge for quantitation with conventional methods. Preliminary research shows that low-count quantitative SPECT (LC-QSPECT) imaging demonstrates reliable quantitation of regional uptake for αRPTs. The purpose of this study is to demonstrate the feasibility, tolerability and performance of LC-QSPECT imaging.

Detailed Description

Not available

Study Timeline

• Status Verified: 2025-10
• Study First Submitted: 2025-10-25
• Study First Submitted QC: 2025-10-25
• Study First Posted: 2025-10-28
• Last Update Submitted: 2025-10-29
• Last Update Posted: 2025-10-30
• Study Start: 2025-11-30
• Primary Completion: 2027-08-31
• Study Completion: 2027-11-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Male
• Target Recruitment: 38

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Spearman's correlation coefficient between the LC-QSPECT estimated uptake in the lesions and intestine with ex vivo activity sampling	Through collection of ex vivo sample (estimated to be 3 months)	The investigators will assess if the correlation (in absolute magnitude) ≥ 0.60 between the tissue and SPECT data against a low correlation of \< 0.2 based on 1-sided normal test at a 5% level.

Secondary Outcome Measures

Name	Time	Method
Correlation between the LC-QSPECT measurements and bone-turnover markers (Spearman Correlation Coefficient)	Through completion of Xofigo treatment (estimated to be 6 months)	Spearman correlation coefficient measures the strength and direction of the linear correlation (dependence) between 2 variables after converting the raw data to ranks, giving a value between +1 and -1 inclusive, where 1 indicates perfect positive correlation, 0 indicates no correlation, and -1 indicates perfect negative correlation.
LC-QSPECT related adverse events	From start of LC-QSPECT imaging through 12 hours following LC-QSPECT imaging
Percentage of enrolled patients who withdraw from the study due to adverse events at least possibly related to LC-QSPECT (as chosen by patients or treating physician team)	From start of LC-QSPECT imaging through 12 hours following LC-QSPECT imaging
Feasibility of conducting LC-QSPECT will be determined by percentage of SPECT scans that can be processed using the investigators' computational method	Through completion of LC-QSPECT imaging (estimated to be 3 months)	Feasibility is defined as at least 80% of scans able to be processed.
Correlation between the LC-QSPECT measurements and PSA (Spearman Correlation Coefficient)	Through completion of Xofigo treatment (estimated to be 6 months)	Spearman correlation coefficient measures the strength and direction of the linear correlation (dependence) between 2 variables after converting the raw data to ranks, giving a value between +1 and -1 inclusive, where 1 indicates perfect positive correlation, 0 indicates no correlation, and -1 indicates perfect negative correlation.
Correlation between the LC-QSPECT measurements and PSA doubling time (Spearman Correlation Coefficient)	Through completion of Xofigo treatment (estimated to be 6 months)	Spearman correlation coefficient measures the strength and direction of the linear correlation (dependence) between 2 variables after converting the raw data to ranks, giving a value between +1 and -1 inclusive, where 1 indicates perfect positive correlation, 0 indicates no correlation, and -1 indicates perfect negative correlation.
Correlation between the LC-QSPECT measurements and Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire (Spearman Correlation Coefficient)	Through completion of Xofigo treatment (estimated to be 6 months)	* Spearman correlation coefficient measures the strength and direction of the linear correlation (dependence) between 2 variables after converting the raw data to ranks, giving a value between +1 and -1 inclusive, where 1 indicates perfect positive correlation, 0 indicates no correlation, and -1 indicates perfect negative correlation.; * The FACT-P scale is a tool used for assessing the health-related quality of life (QoL) in men with prostate cancer. It consists of 27 core items which assess patient function in four domains (Physical, Social/Family, Emotional, and Functional well-being), and it is further supplemented by 12 site specific items to assess for prostate-related symptoms. Each item is rated on a 0 to 4 Likert type scale, and then combined to produce a global QoL score, with a range of scores of 0 to 156. Higher scores represent better QoL.
Correlation between the LC-QSPECT measurements and EuroQol-5 (EQ-5D-5L) questionnaire (Spearman Correlation Coefficient)	Through completion of Xofigo treatment (estimated to be 6 months)	* Spearman correlation coefficient measures the strength and direction of the linear correlation (dependence) between 2 variables after converting the raw data to ranks, giving a value between +1 and -1 inclusive, where 1 indicates perfect positive correlation, 0 indicates no correlation, and -1 indicates perfect negative correlation.; * EQ-5D-5L is a descriptive system for health-related quality of life states in adults, consisting of five dimensions (Mobility, Self-care, Usual activities, Pain \& discomfort, Anxiety \& depression), each of which has five severity levels that are described by statements appropriate to that dimension. Scale Minimum: 0. Scale Maximum: 100. Higher score indicates better outcome.
Correlation between the LC-QSPECT measurements and Brief Pain Inventory (BPI) questionnaire (Spearman Correlation Coefficient)	Through completion of Xofigo treatment (estimated to be 6 months)	* Spearman correlation coefficient measures the strength and direction of the linear correlation (dependence) between 2 variables after converting the raw data to ranks, giving a value between +1 and -1 inclusive, where 1 indicates perfect positive correlation, 0 indicates no correlation, and -1 indicates perfect negative correlation.; * BPI score ranges from 0 to 10 with a higher score denoting a higher pain severity.
Correlation between the LC-QSPECT measurements and bone turnover (Spearman Correlation Coefficient)	Through completion of Xofigo treatment (estimated to be 6 months)	Spearman correlation coefficient measures the strength and direction of the linear correlation (dependence) between 2 variables after converting the raw data to ranks, giving a value between +1 and -1 inclusive, where 1 indicates perfect positive correlation, 0 indicates no correlation, and -1 indicates perfect negative correlation.
Percentage of times that the use of the LC-QSPECT procedure resulted in any changes in treatment plans of the patients	Through completion of Xofigo treatment (estimated to be 6 months)
Performance of the LC-QSPECT procedure using a no-gold-standard evaluation technique.	Through completion of LC-QSPECT imaging (estimated to be 3 months)	* The investigators will use the no-gold-standard technique to assess whether the LC-QSPECT technique yields precise performance on the task of isotope uptake quantification, where slope and noise will be estimated and the noise-to-slope ratio (NSR) will be calculated.; * The no-gold-standard technique can be found here: Jha AK, Caffo B, Frey EC. A no-gold-standard technique for objective assessment of quantitative nuclear-medicine imaging methods. Phys Med Biol. 2016 Apr 7;61(7):2780-800. doi: 10.1088/0031-9155/61/7/2780. Epub 2016 Mar 16. PMID: 26982626; PMCID: PMC4921224 and here: Yan Liu, Ziping Liu, Zekun Li, Daniel Thorek, Barry Siegel, Abhinav Jha, "No-gold-standard evaluation of quantitative SPECT methods for alpha-particle radiopharmaceutical therapy", Journal of Nuclear Medicine Jun 2023, 64 (supplement 1) P1331

Trial Locations

Locations (1)

Washington University School of Medicine; 🇺🇸 St Louis, Missouri, United States