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

NCT07208487 | Completed

• 1 other identifier: 2025ky281
• Study Type: observational
• Target: 41
• Locations: 1 country
• Sites: 1

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.

Conditions

Malignant Tumors

Keywords

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

Outcome Measures

Primary Outcomes (1)

• Tumor size

  Referencing 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.

  4 months post-surgery

Study Arms (1)

125I seed implantation treatment group

Inform the patient of relevant precautions and obtain signed informed consent. Upload CT data in DICOM format to the TPS system. Contour the tumor target volume and critical organs layer by layer. Design the needle insertion direction, angle, and depth. Determine the prescribed dose, number of implants, and activity. Obtain the Dose and Volume Histogram (DVH). For patients without prior external beam radiotherapy, the prescribed dose is 120 Gy. For those with prior external beam radiotherapy, the prescribed dose ranges from 80 to 100 Gy, ensuring surrounding critical organs receive doses within safe limits. Position, immobilize, disinfect, and drape the patient according to surgical positioning. After instructing the patient to hold their breath, perform CT scanning for localization. Following local anesthesia, complete particle implantation according to the preoperative plan. After particle implantation, perform another CT scan to verify dose distribution.

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

patients with malignant tumors who underwent 125I seed implantation therapy at the Department of Nuclear Medicine, Jiangxi Cancer Hospital between November 2019 and November 2023 and received preoperative 18F-FDG PET/CT scans.

You may qualify if:

• (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

You may not qualify if:

• (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.

Sponsors & Collaborators

• Jiangxi Provincial Cancer Hospital: lead

Study Sites (1)

Jiangxi Cancer Hospital

Nanchang, Jiangxi, China

Location

Related Publications (1)

• Watanabe H, Okada M, Kaji Y, Satouchi M, Sato Y, Yamabe Y, Onaya H, Endo M, Sone M, Arai Y. [New response evaluation criteria in solid tumours-revised RECIST guideline (version 1.1)]. Gan To Kagaku Ryoho. 2009 Dec;36(13):2495-501. Japanese.

  PMID: 20009446 BACKGROUND

Biospecimen

Retention: SAMPLES WITHOUT DNA

CT scans AND PET/CT parameters

MeSH Terms

Conditions

Neoplasms

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 27, 2025
• First Posted: October 6, 2025
• Study Start: January 1, 2019
• Primary Completion: November 1, 2024
• Study Completion: December 1, 2024
• Last Updated: October 6, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)