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Clinical Study of Pretreatment PET/CT Parameters for Predicting the Efficacy of 125I Seed Implantation in the Treatment of Malignant Tumors

Clinical Study of Pretreatment PET/CT Parameters for Predicting the Efficacy of 125I Seed Implantation in the Treatment of Malignant Tumors

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT07208487
Enrollment
41
Registered
2025-10-06
Start date
2019-01-01
Completion date
2024-12-01
Last updated
2025-10-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Malignant Tumors

Keywords

125I seed; Brachytherapy, Malignant tumors, PET/CT, MTV, TLG, SUV, Efficacy prediction

Brief summary

This study aimed to determine if pre-treatment 18F-FDG PET/CT metabolic parameters could predict the effectiveness of 125I seed implantation for malignant tumors. In a retrospective analysis of 41 patients with 69 lesions, various parameters were measured. The results identified Metabolic Tumor Volume (MTV) as the most significant independent prognostic factor, outperforming other standardized uptake values (SUV) and ratios. A higher MTV was associated with a worse treatment outcome, suggesting it is a valuable predictor for guiding treatment decisions.

Detailed description

Objective The purpose of the research is to assess the role of pretreatment 18F-FDG PET/CT parameters in predicting the efficacy of 125I seed implantation in the treatment of malignant tumors, in order to allow for timely clinical interventions and adjustments in the treatment regimen. Methods A retrospective analysis was made on patients who were treated with 125I seed implantation for malignant tumors and underwent 18F-FDG PET/CT before treatment from November 2019 to November 2023 in our hospital. The clinical data of 41 patients with 69 lesions were collected completely, including age, gender, primary tumor and seed implantation sites. Metabolic parameters including TLG, MTV, SUVmax-bw, SUVmax-bsa, SUVmax-lbm, SUVmean-bw, SUVmean-bsa, SUVmean-lbm, SUVpeak-bw, SUVpeak-bsa, SUVpeak-lbm, TLR, TLMR, TBR and TBMR were measured at pretreatment PET/CT. The patients were followed up at 4 months after the procedure by CT scans. The efficacy of response was evaluated by using the response evaluation criteria in solid tumors (RECIST1.1). Results The area under the curves for TLG and MTV were 0.815 (P\<0.001) and 0.804 (P\<0.001) respectively. Univariate logistic regression analysis and multivariate logistic regression analysis. The results showed that only the MTV (OR: 6.477, 95%CI: 1.157-36.271, P=0.034) was an independent prognostic factor for the efficacy of 125I seed implantation for malignant tumors. Conclusion In patients with malignant tumors treated with 125I seed implantation, the 18F-FDG PET/CT parameters MTV in the prediction of the efficacy was superior to SUVmax, SUVmean and SUVpeak which normalized by body weight, body surface area and lean body mass, as well as to TLR, TLMR, TBR and TBMR. The 18F-FDG PET/CT parameter MTV was an independent prognostic factor for the efficacy of 125I seed implantation in the treatment of malignant tumors.

Interventions

None listed

Sponsors

Jiangxi Provincial Cancer Hospital
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
RETROSPECTIVE

Eligibility

Sex/Gender
ALL
Healthy volunteers
No

Inclusion criteria

(1) Interval between PET/CT imaging and 125I seed implantation ≤4 weeks; (2)CT follow-up performed 4 months post-125I seed implantation; (3) Primary tumor pathologically or cytologically diagnosed as malignant; (4) Metastatic or recurrent lesions implanted with 125I confirmed by cytological aspiration or imaging

Exclusion criteria

(1) Lesions too small or SUVmax \< 2.5, rendering them unidentifiable by software for PET/CT parameter measurement; (2) Two 125I seed implantation procedures performed within 6 months for the same lesion; (3) Incomplete clinical or imaging data.

Design outcomes

Primary

MeasureTime frameDescription
Tumor size4 months post-surgeryReferencing the Response Evaluation Criteria in Solid Tumors (RECIST 1.1), efficacy is categorized as Complete Response (CR), Partial Response (PR), Stable Disease (SD), or Progression Disease (PD). Objective response rate (ORR) was defined as the proportion of lesions achieving CR or PR, while non-ORR was defined as the proportion of lesions achieving SD or PD.

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026