PSMA-radioguided surgery

Given the difficulty visualizing lymph node involvement with pre-operative imaging alone, and the potential to miss metastatic nodal involvement on template PLND, radioguided surgery has been proposed as a technique to improve intra-operative detection and clearance. 99mTechnetium (99mTc) is a frequently used radioisotope in nuclear medicine, with favourable radiation properties and commercial availability[11]. It has a 6-hour half-life, and is suited to allow target tissue accumulation, while minimizing patients and investigator radiation exposure. Novel molecule-targeted radiopharmaceuticals using 99mTC and other radioisotopes in the setting of PC have increasing potential for diagnostic imaging, monitoring of therapeutic interventions and directed surgery[11, 12]. In relation to radioguided surgery, 99mTC -based PSMA-radioguided surgery (99mTc-PSMA-RGS) was deployed in a feasibility study. Using a specifically designed 99mTc based tracer, 99mTc-mas3-y-nal-k(Sub-KuE), or in short Tc-99m-PSMA I&S, combined with a gamma probe, guidance of the surgical resection of recurrent PC lymph node metastases was undertaken in 132 patients, yielding a sensitivity of 84% and specificity of 100% and detecting metastases as small as 3mm[15, 16]. This raises the question as to whether a combination of PSMA PET/CT imaging and PSMA-radioguided surgery may increase the cure rate in patients undergoing operative management of PC, by increasing detection sensitivity and specificity of nodal metastases.

Inclusion Criteria:

• Male, aged ≥ 18 years.
• Hormone-sensitive recurrent prostate cancer after radical prostatectomy
• <3 soft tissue lesions (lymph node; connective tissue) within the pelvis or retroperitoneum with sufficient PSMA expression (≥3 times regional vascular activity level) as determined by PSMA-based PET
• PSA-value <4ng/mL
• Had a PSMA PET/CT within 60 days before surgery
• Suitable for salvage lymph node dissection, as per institutional guidelines.
• WHO performance status 0,1, or 2.
• Written informed consent.

Exclusion Criteria:

• Suspicion of local recurrent prostate cancer within the prostatic fossa not treatable by surgery
• Nonregional lymphadenopathy (cM1a) or distant metastases (cM1b/c) as assessed by preoperative PSMA PET/CT.
• Ongoing androgen deprivation therapy (ADT) or within 6 months prior to surgery.
• Severe claustrophobia interfering with PET/CT or SPECT/CT scanning.

men with prostate cancer

men with hormone-sensitive recurent prostate cancer