FDG-PET/CT in Monitoring Response of Pelvic Lymph Node Metastases to Neoadjuvant Chemotherapy in Bladder Cancer
Mertens LS, Fioole-Bruining A, van Rhijn BW, Kerst JM, Bergman AM, Vogel WV, Vegt E, Horenblas S. J Urol. 2012 Nov 6. pii: S0022-5347(12)05474-2. doi: 10.1016/j.juro.2012.11.009. [Epub ahead of print]

Source

Department of Urology, The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands. Electronic address: l.mertens@nki.nl.

Abstract

PURPOSE:

To evaluate F18 fluorodeoxyglucose (FDG) - positron emission tomography / computed tomography (PET/CT) for monitoring response of pelvic lymph node metastases to neoadjuvant chemotherapy (NAC) in bladder cancer. A comparison was made with contrast-enhanced CT (CECT).

MATERIALS AND METHODS:

Nineteen consecutive patients with lymph node positive bladder cancer who underwent FDG-PET/CT and CECT scanning before and after a median of 4 cycles (range: 2-4) of NAC, between September 2011 and April 2012 were studied. Metabolic response was assessed according to EORTC recommendations, based on change in FDG uptake on FDG-PET/CT. Radiological response was assessed on CECT, according to RECIST 1.1. All patients underwent a pelvic lymph node dissection (PLND). Histopathological evaluation was used as the gold standard for nodal response.

RESULTS:

Before NAC, hypermetabolic FDG uptake, matching with the LN metastases, was seen in all 19 patients. Evaluating nodal response with PET/CT was feasible in all patients. According to histopathology, 16 patients were responders, of whom 14 obtained a pathological complete response of the LNs. PET/CT correctly distinguished between responders and non-reponders in 18/19 (94.7%), and CECT in 15/19 patients (78.9%). PET/CT correctly distinguished between complete responders and patients with residual disease in 13/19 patients (68.4%), and CECT in 12/19 patients (63.2%).

CONCLUSIONS:

Although no definitive conclusions can be drawn from these preliminary data, PET/CT scanning appears feasible in evaluating nodal response to NAC and distinguishing between responders and non-responders.