방사선의학 웹진

바로가기  >

Abstract
Objectives: This study evaluated the prognostic value of basal and interim [68Ga]Ga-DOTA-TOC PET/CT in patients with locally advanced or metastatic neuroendocrine tumour (NET) who received peptide receptor radionuclide therapy (PRRT).

Methods: Patients with NET who received PRRT with [177Lu]Lu-DOTA-TATE at our institution were retrospectively reviewed. Among them, patients who underwent both basal and interim (after two cycles of PRRT) [68Ga]Ga-DOTA-TOC PET/CT were included. Alongside clinicopathologic parameters, PET parameters of maximum standardised uptake value (SUVmax), tumour-to-liver ratio (TLR), whole tumour volume (WTV) and total receptor expression (TRE: WTV multiplied by mean standardised uptake value) were obtained from basal and interim [68Ga]Ga-DOTA-TOC PET/CT, and their proportional changes (∆) were assessed for associations with progression-free survival (PFS) using Kaplan-Meier analysis, log-rank tests, and a Cox proportional-hazards regression model.

Results: Twenty-four patients were finally included (10 men and 14 women, median age of 56.5 years, age range 32-74 years). Among them, 16 patients (66.7%) experienced disease progression. In univariate analysis, high ∆WTV (≥ -10%, hazard ratio [HR] = 3.053 [1.003-9.289], p = 0.049) and high ∆TRE (≥ -21%, HR = 3.567 [1.144-11.122], p = 0.028) were significantly associated with shorter PFS. In multivariate analyses adjusted for WHO grade, high ∆WTV (HR = 3.345 [1.055-10.601], p = 0.043) and high ∆TRE (HR = 3.894 [1.194-12.695], p = 0.024) were significant predictors of shorter PFS.

Conclusion: The study demonstrates that basal and interim [68Ga]Ga-DOTA-TOC PET/CT scans, through proportional changes in WTV and TRE, effectively predict PFS in neuroendocrine tumour patients receiving PRRT.

Key points: Question Peptide receptor radionuclide therapy is utilised for patients with somatostatin receptor-positive well-differentiated neuroendocrine tumours; however, prognostic predictors are not well established. Findings Progression-free survival was significantly associated with the proportional change in whole tumour volume and total receptor expression between basal and interim [68Ga]Ga-DOTA-TOC PET/CT. Clinical relevance Interim [68Ga]Ga-DOTA-TOC PET/CT can serve as a valuable imaging method to predict prognosis of peptide receptor radionuclide therapy.

Affiliations

Eonwoo Shin 1 2, Yong-Il Kim # 3 4, Changhoon Yoo # 5 6, Yeokyeong Shin 7, Baek-Yeol Ryoo 8 7, Dong Yun Lee 1 8, Jin-Sook Ryu 1 8
1Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
2Department of Nuclear Medicine, GangNeung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Republic of Korea.
3Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. kyi821209@naver.com.
4Theranostics Center, Asan Cancer Institute, Asan Medical Center, Seoul, Republic of Korea. kyi821209@naver.com.
5Theranostics Center, Asan Cancer Institute, Asan Medical Center, Seoul, Republic of Korea. yooc@amc.seoul.kr.
6Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. yooc@amc.seoul.kr.
7Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
8Theranostics Center, Asan Cancer Institute, Asan Medical Center, Seoul, Republic of Korea.
#Contributed equally.