PET/CT-guided salvage surgery protocol. Results with ROLL technique and PET probe

ObjectiveTo assess the value of intraoperatory radioguided probe detection to guide surgical resection of malignant lesions previously detected by 18F-FDG PET-CT.MaterialTwelve consecutive patients with suspected tumor recurrence detected by 18F-FDG PET-CT considered resectable were enrolled in the study. Ultrasound guided fine needle aspiration (FNA) before surgery was performed in 6 patients and CT guided biopsy was performed in 1 patient. In 5 patients with accessible lesions, a radioguided occult lesion localization (ROLL) technique was performed after injection of 99mTc-colloid (1.7–2.4 mCi) inside the lesion under ultrasound or CT guidance, pre-operatively. Radioguided surgical detection was then carried out 19–24 h afterwards using the gamma probe. In 7 patients with non-accessible needle lesions or multiple lesions, 9.5–10.5 mCi of 18F-FDG were injected 3–5 h before radioguided surgery using a PET-dedicated probe (Gamma locator DXI-GF&E).ResultsROLL technique: all lesions injected with nanocolloid were resected (6 lesions in 5 patients, 1 patient with 2 lesions), and recurrence was histologically confirmed. PET probe: fourteen out of 16 hypermetabolic lesions detected on the PET-CT were resected. One cervical and one mediastinal lymph node in different patients could not be excised. Histological recurrence was confirmed in 12 out of 14 lesions. In one patient, the 2 lymph nodes excised were inflammatory.Conclusions18F-FDG PET-CT can be key in deciding surgical approach and appropriate radioguided protocol. When lesions are solitary and easily accessible, ROLL technique seems the method of choice. PET probe is more adequate for less accessible lesions.

ResumenObjetivoEvaluar la utilidad intraoperatoria de sondas de detección radioisotópica en la exéresis quirúrgica de lesiones tumorales previamente detectadas mediante 18F-FDG PET/TC.MaterialSe han estudiado 12 pacientes consecutivos con elevada sospecha de recidiva tumoral detectada por 18F-FDG PET/TC potencialmente resecables. En los que ha sido posible se ha realizado confirmación histológica, en 6 pacientes mediante PAAF ecodirigida y en un paciente mediante BAG guiada por TC. A 5 pacientes con lesiones accesibles se realizó técnica ROLL (Radioguided Occult Lesion Localisation) tras punción intralesional guiada por ecografía/TC de 99mTc-coloide (1.7–2.4 mCi), con detección entre 19–24 horas intraquirúrgica mediante sonda gamma. A los 7 pacientes con lesiones no accesibles o múltiples, se inyectó la 18F-FDG (9.5–10.5 mCi) entre 3–5 horas previas a la cirugía que se realizó con sonda PET dedicada (Gamma locator DXI-GF&E).ResultadosTécnica ROLL: todas las lesiones marcadas con coloide fueron resecadas (6 lesiones en 5 pacientes, un paciente con dos lesiones) confirmándose la recidiva mediante anatomía patológica. Sonda PET: 14 de las 16 lesiones hipermetabólicas detectadas por la PET/TC inicial fueron resecadas. No se resecó una adenopatía cervical y una mediastínica pertenecientes a dos pacientes diferentes. En 12/14 lesiones la histología confirmo recidiva. En un paciente, dos adenopatías eran reactivas.ConclusionesLa 18F-FDG PET/TC es determinante para la elección del protocolo de cirugía radioguiada. Si las lesiones son únicas y de fácil acceso a la PAAF, el ROLL es la técnica de elección. La sonda PET se debería aplicar en lesiones no accesibles.