[⁶⁸Ga]Ga-FAPI-46 PET/CT for penile cancer - a feasibility study.

Area of Science:

• Oncology
• Nuclear Medicine
• Radiochemistry

Background:

• Penile cancer prognosis depends on localized stage and timely lymphatic disease treatment.
• Conventional imaging often fails to detect occult lymph node metastasis, impacting survival.
• Fibroblast activation protein inhibitor (FAPI) imaging shows potential for non-invasive staging in various cancers.

Purpose of the Study:

• To evaluate the utility of [⁶⁸Ga]Ga-FAPI-46 PET/CT as a non-invasive staging tool for penile cancer.
• To assess FAPI uptake in primary penile tumors and lymph nodes.
• To determine if [⁶⁸Ga]Ga-FAPI-46 PET/CT can identify occult lymph node metastasis.

Main Methods:

• A single-center pilot study involving 11 patients with penile cancer.
• Preoperative [⁶⁸Ga]Ga-FAPI-46 PET/CT imaging was performed before surgical treatment.
• Postoperative histopathology results were compared with PET/CT findings.

Main Results:

• [⁶⁸Ga]Ga-FAPI-46 PET/CT demonstrated increased FAPI uptake in primary penile tumor sites (SUV_max 16.2).
• Significantly elevated FAPI uptake was observed in histopathologically confirmed lymph node regions (SUV_max 17.9).
• No false-positive FAPI uptake was detected in the pilot cohort.

Conclusions:

• [⁶⁸Ga]Ga-FAPI-46 PET/CT shows promise for detecting lymph node metastasis in penile cancer.
• This imaging modality may help identify patients with occult metastasis.
• FAPI PET/CT could potentially guide surgical decisions, possibly avoiding unnecessary lymph node dissection.