RESUMEN
Recently, prostate-specific membrane antigen radioguided surgery (PSMA-RGS) was introduced for targeted resection of localised prostate cancer recurrence. Preliminary results show that PSMA-RGS is very sensitive and specific in tracking suspicious lesions intraoperatively. Prerequisite for PSMA-RGS is a positive 68Ga-PSMA positron emission tomography (PET) scan with a preferably singular soft tissue or lymph node recurrence. The first 63 patients treated with PSMA-RGS were analyzed. The extracorporal analysis of a total of 277 tissue specimens yielded the following test quality criteria regarding the presence of malignant tissue: sensitivity 86.2%, specificity 96.4%, positive predictive value 94%, negative predictive value 91.5%. Oncological follow-up data was available from 59 patients. There was a drop in PSA (prostate specific antigen) below 0.2 ng/ml in 38 patients (67%). Of these 38 patients, 17 (45%) are free of biochemical recurrence after a median follow-up of 12.3 months (6.7-31.9 months). Clavien-Dindo grade III complications occurred in 6 of 63 patients (9.5%). In summary, PSMA-RGS proved to be of high value in patients with localised prostate cancer recurrence for exact localisation and resection of oftentimes small metastatic tissue using intraoperative and ex vivo gamma-probe measurements. Furthermore, PSMA-RGS has the potential to positively influence oncological outcomes. However, patient identification on the basis of 68Ga-PSMA PET imaging and clinical parameters is crucial to obtain satisfactory results.
Asunto(s)
Antígenos de Superficie/análisis , Glutamato Carboxipeptidasa II/análisis , Recurrencia Local de Neoplasia/cirugía , Neoplasias de la Próstata/cirugía , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único/métodos , Cirugía Asistida por Computador/métodos , Anciano , Ácido Edético/análogos & derivados , Isótopos de Galio , Radioisótopos de Galio , Humanos , Metástasis Linfática/diagnóstico por imagen , Metástasis Linfática/patología , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Recurrencia Local de Neoplasia/diagnóstico por imagen , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Oligopéptidos , Próstata/diagnóstico por imagen , Próstata/patología , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único/instrumentaciónRESUMEN
Recently, PSMA-radioguided surgery (PSMA-RGS) was introduced for targeted resection of localized prostate cancer recurrence. Prerequisite for preoperative patient selection and localization of tumor recurrence is a positive 68Ga-HBED-CC PSMA positron emission tomography (PET) scan with preferably only singular soft tissue or lymph node recurrence. After injection of In-PSMA I&T or Tc-PSMA-I&S single photon emission computer tomography (SPECT)/computer tomography (CT) examination is performed in every patient to verify radiotracer uptake in tumor lesions. In a preliminary study, 111In-PSMA I&T SPECT/CT could detect about half of the 68Ga-HBED-CC PSMA PET-positive lesions, while nearly all PET-positive lesions could be detected using PSMA-RGS and also five additional lesions compared to 68Ga-HBED-CC-PSMA PET. Follow-up data from 55 patients show a PSA reduction >50% and >90% in 44 (80%) and 29 (53%) patients, respectively. In 34 (62%) patients, a PSA drop to <0.2 ng/ml was observed. In all, 15 (27%) patients received further PC-specific treatment; the remaining 40 (73%) patients did not undergo further treatment. In 33% of patients, surgery-related complications were noted; however, most were regarded as minor. Thus, PSMA-RGS seems to be of high value in patients with localized prostate cancer recurrence with exact localization and resection of metastatic tissue. However, patient selection based on 68Ga-PSMA PET imaging and clinical parameters is crucial to obtain satisfactory oncological results.