Leveraging Illuccix’s® Established Imaging Performance: An Intraindividual Comparison with Gozellix® PET

Leveraging Illuccix’s® Established Imaging Performance: An Intraindividual Comparison with Gozellix® PET

⁶⁶Ga-PSMA-11 (Illuccix®) has demonstrated safety and tolerability in numerous studies.¹ The recently FDA-approved Gozellix® ⁶⁸Ga-PSMA-11 kit offers a lon-ger shelf-life, thereby increasing patient access to ⁶⁸Ga-PSMA-11 PET imaging by increasing the existing prostate-specific membrane antigen (PSMA) PET agent distribution network.

Illuccix and Gozellix are both indicated for PET imaging of PSMA-positive lesions in patients with prostate cancer with suspected metastasis and candi\dates for initial definitive therapy or with suspected recurrence based on elevated serum prostate-specific antigen (PSA) levels.^2,3

Gozellix delivers the same clinical performance as Illuccix. Gozellix is formulated to support increased patient access, more scalable preparation, scheduling flexibility, and clinical throughput. This longer shelf-life allows for greater flexibility in patient scheduling and an improved transportation range for distributors who need to transport the PET radiopharmaceuticals. Local hospitals and radiopharmacies can significantly improve clinical practice through increased patient access, more scalable preparation, scheduling flexibility, and clinical throughput. In addition to generators, Gozellix offers the option to use cyclotron ⁶⁸Ga, enabling greater flexibility and potentially reducing costs for imaging centers transitioning to new generator and cyclotron infrastructure.

Building upon Illuccix’s established clinical imaging performance, we present a case series of patients who received both Illuccix and Gozellix PET/CT scans (within 1-6 days and with 55–65-minute uptake times) to demonstrate the similarity of biodistribution and lesion uptake as characterized by the average of SUV_max and SUV_mean across 3 readers. All patient cases demonstrate lesions detected on both scan types with similar maximum and mean standardized uptake values (SUV_max and SUV_mean, respectively) and concordance across both Gozellix and Illuccix scans (Table 1).

Table 1.

Average of SUV_max and SUV_mean across 3 readers of intraindividual Illuccix and Gozellix PET/CT scans.

Conclusion

This case series highlights the similar biodistribution and SUV_max on Illuccix and Gozellix scans, which both utilize ⁶⁸Ga-PSMA-11 for PET/CT imaging. We demonstrate high image quality and comparable tracer uptake with both Illuccix and Gozellix among a range of tumor scores.

Case 1

A 67-year-old male was diagnosed with prostate cancer 2 months prior with a Gleason Score of 4+4, PSA 8.9 ng/mL, ISUP Grade 4, and tumor score TX. The patient underwent an Illuccix PET scan and, one day later, underwent a Gozellix PET scan. The patient had an evaluable left internal iliac lymph node lesion detected on both Illuccix and Gozellix PET images, with SUV_max of 49.62 and 47.30, respectively, and SUV_mean of 16.35 and 17.99, respectively (Figure 1).

Figure 1a.

(A) Illuccix (top) and Gozellix (bottom) PSMA PET and fused PSMA PET/CT images of a 67-year-old male. Arrows indicate a lymph node lesion in the left internal iliac region. (B) MIP from Illuccix (left) and Gozellix (right).

Figure 1b.

Case 2

A 79-year-old male was diagnosed with prostate cancer 1 month prior with a Gleason Score of 4+4, PSA 7.9 ng/mL ISUP Grade 4, and tumor score T2b. The patient underwent an Illuccix PET scan, and, two days later, underwent a Gozellix PET scan. The patient had an eval-uable right rib bone lesion detected on both Illuccix and Gozellix PET images, with SUV_max of 46.78 and 57.98, respectively, and SUV_mean of 11.58 and 11.35, respectively (Figure 2).

Figure 2a.

(A) Illuccix (top) and Gozellix (bottom) PSMA PET and fused PSMA PET/CT images of a 79-year-old male. Arrows indicate a right rib bone lesion. (B) MIP with Illuccix (left) and Gozellix (right).

Figure 2b.

Case 3

A 65-year-old male was diagnosed with prostate cancer 0.5 months prior with a Gleason Score of 9-10, PSA 12.1 ng/mL, ISUP Grade 5, and tumor score T3. The patient underwent an Illuccix PET scan, and, six days later, underwent a Gozellix PET scan. The patient had an evalu-able mesorectal lymph node lesion on both Illuccix and Gozellix PET images, with mean SUV_max values of 15.55 and 13.93, respectively, and mean SUV_mean values of 6.00 and 6.45, respectively (Figure 3).

Figure 3a.

(A) Illuccix (top) and Gozellix (bottom) PSMA PET and fused PSMA PET/CT images of a 65-year-old male. Arrows indicate a mesorectal lymph node lesion. (B) MIP with Illuccix (left) and Gozellix (right).

Figure 3b.

References

1. Purysko AS, Abreu AL, Lin DW, Punnen S. Not all prostate-specific membrane antigen imaging agents are created equal: diagnostic accuracy of Ga-68 PSMA-11 PET/CT for initial and recurrent prostate cancer. Applied Radiology. 2024;2:22-35.
2. Gozellix (kit for the preparation of gallium Ga 68 gozetotide injection) prescribing information. Telix Pharmaceuticals; 2025.
3. Illuccix (kit for the preparation of gallium Ga 68 gozetotide injection) prescribing information. Telix Pharmaceuticals; 2025.

Disclosures: M Ghesani has received support from Telix Pharmaceuticals, ITM, Novartis, Serac Life Sciences, Lantheus, and Blue Earth. HR Kulkarni is an employee of BAMF Health. Medical writing and editing support provided by Jess Roetman, Grace Wang, Stefanie Martina (Telix Pharmaceuticals). Image preparation support provided by John Ceccoli, Tim Houston, and Kevin McClure (Telix Pharmaceuticals). Data presented was collected as part of Telix-sponsored study and published with Telix permission