Role of textural heterogeneity parameters in patient selection for 177Lu-PSMA therapy via response prediction.

Zain Khurshid,Markus Essler,Hojjat Ahmadzadehfar,Ralph A Bundschuh,Florian C Gaertner,Norbert Zsóter,László Papp

doi:10.18632/oncotarget.26051

Zain Khurshid, Markus Essler + Show 5 more

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https://doi.org/10.18632/oncotarget.26051

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Abstract

PurposeProstate cancer is most common tumor in men causing significant patient mortality and morbidity. In newer diagnostic/therapeutic agents PSMA linked ones are specifically important. Analysis of textural heterogeneity parameters is associated with determination of innately aggressive and therapy resistant cell lines thus emphasizing their importance in therapy planning. The objective of current study was to assess predictive ability of tumor textural heterogeneity parameters from baseline 68Ga-PSMA PET prior to 177Lu-PSMA therapy.ResultsEntropy showed a negative correlation (rs = −0.327, p = 0.006, AUC = 0.695) and homogeneity showed a positive correlation (rs = 0.315, p = 0.008, AUC = 0.683) with change in pre and post therapy PSA levels.ConclusionsStudy showed potential for response prediction through baseline PET scan using textural features. It suggested that increase in heterogeneity of PSMA expression seems to be associated with an increased response to PSMA radionuclide therapy.Materials and MethodsRetrospective analysis of 70 patients was performed. All patients had metastatic prostate cancer and were planned to undergo 177Lu-PSMA therapy. Pre-therapeutic 68Ga- PSMA PET scans were used for analysis. 3D volumes (VOIs) of 3 lesions each in bones and lymph nodes were manually delineated in static PET images. Five PET based textural heterogeneity parameters (COV, entropy, homogeneity, contrast, size variation) were determined. Results obtained were then compared with clinical parameters including pre and post therapy PSA, alkaline phosphate, bone specific alkaline phosphate levels and ECOG criteria. Spearman correlation was used to determine statistical dependence among variables. ROC analysis was performed to estimate the optimal cutoff value and AUC.

Highlights

Prostate cancer being the most common cancer and second leading cause of death among men in the Western world [1] is under constant surveillance by researchers and medical personnel worldwide
Study showed potential for response prediction through baseline PET scan using textural features. It suggested that increase in heterogeneity of Prostate specific Membrane Antigen (PSMA) expression seems to be associated with an increased response to PSMA radionuclide therapy
Our study showed a potential for response prediction through baseline PSMA PET-computer tomography (CT) scan using textural features

Summary

Introduction

Prostate cancer being the most common cancer and second leading cause of death among men in the Western world [1] is under constant surveillance by researchers and medical personnel worldwide. Prostate cancer tends to be highly aggressive and can lead to significant mortality and morbidity [2]. It is of utmost importance to devise new methods aiming for earlier diagnosis and optimum individualized therapy of prostate cancer. Among the ongoing advancements for the treatment of prostate cancer the possibilities involving Prostate specific Membrane Antigen (PSMA) have gained www.oncotarget.com momentum. In the light of published data it can be deduced that radioligand therapy (RLT) with 177Lu-PSMA is effective and has a low toxicity profile [3]. It is observed that up to 30% of patients do not show and prostate specific antigen (PSA) decline in response to RLT [3, 4]. Establishment of pre-therapeutic biomarkers for patient selection for RLT would be helpful to avoid over-treatment

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