Antireflux catheter improves tumor targeting in liver radioembolization with resin microspheres

PURPOSE We aimed to determine whether antireflux (ARC) catheter may result in better tumor targeting in liver radioembolization using [.sup.90]Y-resin microspheres. METHODS Patients treated with resin microspheres for hepatocellular carcinoma (HCC) and secondary liver malignancies were retrospectively analyzed. All patients underwent a [.sup.99m]Tc-macroaggregated albumin ([.sup.99m]Tc-MAA) single photon emission computed tomography (SPECT) following the planning arteriography with a conventional end-hole catheter. For [.sup.90]Y-microspheres injection, two groups were defined depending on the type of catheter used: an ARC group (n=38) and a control group treated with a conventional end-hole catheter (n=23). [.sup.90]Y positron emission tomography computed tomography (PET/CT) was performed after the therapeutic arteriography. The choice of the catheter was not randomized, but left to the choice of the interventional radiologist. [.sup.99m]Tc-MAA SPECT and [.sup.90]Y PET/CT were co-registered with the baseline imaging to determine a tumor to normal liver ratio (T/N[L.sub.[MAA or 90Y]]) and tumor dose (T[D.sub.[MAA or 90Y]]) for the planning and therapy. RESULTS Overall, 38 patients (115 lesions) and 23 patients (75 lesions) were analyzed in the ARC and control groups, respectively. In the ARC group, T/N[L.sub.90Y] and T[D.sub.90Y] were significantly higher than T/N[L.sub.MAA] and T[D.sub.MAA]. Median (IQR) T/N[L.sub.90Y] was 2.16 (2.15) versus 1.74 (1.43) for T/N[L.sub.MAA] (p < 0.001). Median (IQR) T[D.sub.90Y] was 90.96 Gy (98.31 Gy) versus 73.72 Gy (63.82 Gy) for T[D.sub.MAA] (p < 0.001). In this group, the differences were highly significant for neuroendocrine metastases (NEM) and HCC and less significant for colorectal metastases (CRM). In the control group, no significant differences were demonstrated. CONCLUSION The use of an ARC significantly improves tumor deposition in liver radioembolization with resin microspheres.