Riad Salem

Evaluating 90Y-glass microsphere treatment response of unresectable colorectal liver metastases by [18F]FDG PET: a comparison with CT or MRI

Abstract. The purpose of this prospective study was to evaluate yttrium-90 glass microsphere treatment of unresectable liver metastases by fluorine-18 fluorodeoxyglucose positron emission tomography ([18F]FDG PET), and to compare the effectiveness of [18F]FDG PET for this purpose with that of computed tomography (CT) or magnetic resonance imaging (MRI) and determination of the serum carcinoembryonic antigen (CEA) level. Thirteen hepatic lobes from eight consecutive patients with colorectal cancer referred for 90Y-glass microsphere treatment of unresectable liver metastases who underwent both baseline (pretreatment) and 3-month posttreatment PET were studied. All patients also had correlative pre- and posttreatment CT or MRI for evaluation of the anatomic response and serum CEA determination for assessment of the total tumor load, as well as pretreatment hepatic intra-arterial technetium-99m macroaggregated albumin scan for lung shunting evaluation and hepatic arteriography for assessment of vascular anatomy and treatment. 90Y-glass microspheres were infused via an intra-arterial catheter under low pressure. Dedicated whole-body PET scans were analyzed visually and compared by lesion and by lobe with CT or MRI. A metabolic response after 90Y treatment to single or both hepatic lobes, assessed by PET, was present in a significantly higher proportion of the lobes than was an anatomic response, evaluated by CT or MRI (12 vs 2 lobes respectively, P<0.0002). Posttreatment PET showed no, stable, progressive, and new extrahepatic metastases in two, three, one, and two patients respectively. Following treatment, serum CEA decreased significantly, correlating with PET but not with CT or MRI. Thus, the study demonstrated a significant difference between the metabolic and the anatomic response after 90Y-glass microsphere treatment for unresectable liver metastases in colorectal cancer. PET appears to be an accurate indicator of treatment response.

Closure of a ureterocutaneous fistula with a covered stent-graft.

A 74-year-old woman developed retroperitoneal fibrosis after aortic surgery for a left common iliac artery aneurysm. On the 5th day after repair, a left groin ureterocutaneous fistula developed. Because of the presence of a hostile surgical bed, the fistula was treated with percutaneous nephrotomy and double J stent insertion. Despite proximal control for more than 1 year, the fistula persisted. She was referred to the interventional radiology department for exchange to a nephrostomy with ureteral embolization. Rather than perform embolization of the ureter, we successfully repaired the fistula with a covered stent-graft. The patient was seen again 1 year after stent-graft placement. Output continues to fluctuate but never exceeds 5 mL per day.

Radioembolization : Identifying and Managing Anatomic Variants

The anatomy of the mesenteric system and the hepatic arterial bed has a high degree of variation. Although these anatomical variants have been well described in the literature, the characterization and understanding of regional hepatic perfusion in the context of radioembolization continues to be studied in great depth. The aim of this chapter is to provide a thorough discussion and detailed presentation of the management of arterial variants within the context of radioembolization.

Future Directions in Radioembolization

Radioembolization with yttrium-90 (90Y) micro- spheres represents an innovative approach that has gained increasing awareness and clinical use over the past 5-10 years. The minimal toxicity of radioembolization and the ability to discharge the patient on an outpatient basis make the therapy an attractive alternative in the treatment of primary and metastatic liver malignancies. Patients are able to resume normal activities shortly following treat- ment, with minimal side effects, in contrast to the post-embolization syndrome often associated with current chemoembolic techniques.