In a study published recently in The Journal of Nuclear Medicine, a team of researchers have documented the first in-human application of a novel PET radiotracer.
The researchers led by Xiaoyuan Chen (National Institutes of Health; MD, USA), have demonstrated promising safety and efficacy outcomes for a novel imaging agent, 68Ga-labeled heterodimeric peptide BBN-RGD, which targets both integrin avb3 and the gastrin-releasing peptide receptor.
The team uncovered that the dual receptor targeting nature of this novel PET tracer has advantages over single-receptor targeting as it allows tumor contrast when either or both receptor types are expressed, henceforth, improving binding affinity and increasing the number of effective receptors.
In order to appraise safety and efficacy, the researchers enrolled five healthy volunteers and 13 patients with prostate cancer (four newly diagnosed and nine post-therapy). The researchers observed no adverse side effects during the procedure and at a 2 week follow-up appointment. They also demonstrated that Ga-68-BBN-RGD PET/CT detected 20 bone lesions in seven patients either with primary prostate cancer or after radical prostatectomy.
The researchers hope the imaging agent will help diagnose both early and advanced prostate cancer and aid treatment planning. Chen commented: “Although treatable at the early stage, prostate cancer is prone to metastasis. An effective and specific imaging method of detecting both primary and metastatic lesions is thus of critical importance to manage patients with prostate cancer.”
“This result is better than bone scanning with MDP,” Chen notes, referring to the most commonly used radiotracer. “MDP bone scans are sensitive but lack specificity because localized skeletal accumulation of Tc-99m-MDP can also be observed in the case of trauma and infection.”
“Compounds capable of targeting more than one biomarker have the ability of binding to both early and metastatic stages of prostate cancer, creating the possibility for a more prompt and accurate diagnostic profile for both primary and the metastatic tumors,” explained Chen.
Looking ahead, Chen concluded: “Ga-68-BBN-RGD could play an additive role in staging and detecting prostate cancer and provide guidance for internal radiation therapy using the same peptide labelled with therapeutic radionuclides.”