Partial Radiation Nephrectomy Using 90 Y Resin Microspheres: A Treatment Option for Renal Tumors With Malignant Characteristics in Patients Not Candidates for Surgery.

ABSTRACT: Contrast-enhancing renal masses are likely to be malignant in over 90% of cases due to the high diagnostic accuracy of abdominal imaging. In this situation, tumor biopsy is unnecessary and should be managed as a renal cell carcinoma. Resection remains the only potentially curative treatment. However, as in the case herein presented, comorbidities can prevent surgical resection. Radioembolization with 90 Y microspheres is an intra-arterial procedure capable of delivering high doses of radiation to tumors. The present case demonstrates the concept of partial radiation nephrectomy in treating renal tumors with malignant characteristics in patients not amenable to surgery.

Prostatic Artery Embolization (PAE) Using Polyethylene Glycol Microspheres: Safety and Efficacy in 81 Patients.

PURPOSE: To evaluate the safety and efficacy of prostatic artery embolization (PAE) using polyethylene glycol microspheres (PEGM) in patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: This multicentric prospective study enrolled 81 patients who underwent PAE with 400 ± 75 µm PEGM (HydroPearl®, Terumo, Japan). Results from baseline and 1-, 3-, 6-, and 12-month follow-ups were assessed for subjective outcomes including International Prostate Symptoms Score (IPSS), Quality of life (QoL), and International Index of Erectile Function, and objective outcomes such as peak urinary flow (Qmax) and post-void residual volume (PVR). The visual analogue scale, satisfaction questionnaire, prostatic volume, and prostatic specific antigen levels were also evaluated. Complications were documented using the modified Clavien-Dindo classification. RESULTS: Technical success was obtained in all patients. Clinical success was achieved in 78.5% of patients. Before PAE, 54.3% of patients had an indwelling catheter which was removed in 75% of them after procedure. A statistically significant decrease was observed in IPSS and QoL from baseline to 12 months (20.14 vs 5.89; 4.8 vs 0.63, P < .01), respectively. Objective outcomes also showed a statistically significant improvement in Qmax (+ 114.9%; P < .01), achieving a maximum urinary flow of 14.2 mL/sec, and PVR (decrease 58%; P < .05) at 12 months. Minor complications (Clavien-Dindo grades I-II) occurred in 13.6% of patients, without major complications observed. CONCLUSION: PAE with PEGM is safe and effective treatment in patients with symptomatic BPH, with a significant improvement in both subjective and objective outcomes.

The joint use of 99mTc-MAA-SPECT/CT and cone-beam CT optimizes radioembolization planning.

PURPOSE: To determine which imaging method used during radioembolization (RE) work-up: contrast-enhanced computed tomography (CECT), 99mTc-MAA-SPECT/CT or cone beam-CT (CBCT), more accurately predicts the final target volume (TgV) as well as the influence that each modality has in the dosimetric calculation. METHODS: TgVs from 99mTc-MAA-SPECT/CT, CECT and CBCT were consecutively obtained in 24 patients treated with RE and compared with 90Y PET/CT TgV. Using the TgVs estimated by each imaging modality and a fictitious activity of 1 GBq, the corresponding absorbed doses by tumor and non-tumoral parenchyma were calculated for each patient. The absorbed doses for each modality were compared with the ones obtained using 90Y PET/CT TgV. RESULTS: 99mTc-MAA-SPECT/CT predicted 90Y PET/CT TgV better than CBCT or CECT, even for selective or superselective administrations. Likewise, 99mTc-MAA-SPECT/CT showed dosimetric values more similar to those obtained with 90Y PET/CT. Nevertheless, CBCT provided essential information for RE planning, such as ensuring the total coverage of the tumor and, in cases with more than one feeding artery, splitting the activity according to the volume of tumor perfused by each artery. CONCLUSION: The joint use of 99mTc-MAA-SPECT/CT and CBCT optimizes dosimetric planning for RE procedures, enabling a more accurate personalized approach.

Comparative study of four different spherical embolic particles in an animal model: a morphologic and histologic evaluation.

PURPOSE: To perform a study in a porcine model comparing four different spherical embolic particles in terms of postembolization patency, deformation, and potential for recanalization, with a focus on a relatively new agent--HepaSphere. MATERIALS AND METHODS: Partial embolization of both kidneys was performed in 18 pigs. Nine animals were sacrificed at 48 hours and nine at 4 weeks. In the same animal, the right kidney was embolized with HepaSphere particles ("dry" size, 50-100 microm; presumed final size, 200-300 microm), and the left kidney was alternatively embolized with EmboSphere (100-300 microm), Contour (150-350 microm), or Bead Block (150-350 microm) particles. The authors analyzed the size, deformation, and number of particles in each vessel, their morphologic characteristics, and recanalization. RESULTS: Particle sizes and deformation (1,096 particles) were as follows: HepaSphere, 225.3 microm +/- 67 and 26% +/- 19.7, respectively; EmboSphere, 132.9 microm +/- 36 and 18.1% +/- 14.2; Bead Block, 108.1 microm +/- 38 and 16.5% +/- 13.9; and Contour, 240.8 microm +/- 135 and 55.5% +/- 33. HepaSphere and Bead Block particles were distally located, and EmboSphere and Contour particles were located more proximally. EmboSphere and Bead Block particles were round, HepaSphere particles were round and/or ovoid, and Contour particles had an amorphous aspect. EmboSphere particles had a higher tendency to aggregate. No recanalization was seen with HepaSphere particles, and variable recanalization was observed with the others. CONCLUSIONS: Despite similar initial morphologic characteristics, the performance of the agents tested in this study differed in terms of final size, shape, deformation, and luminal recanalization. These differences have potential clinical relevance, and the knowledge of the differing embolic performance may be helpful in choosing agents for specific therapeutic purposes.

Safety and efficacy assessment of flow redistribution by occlusion of intrahepatic vessels prior to radioembolization in the treatment of liver tumors.

We evaluated the feasibility, safety, and efficacy of radioembolization (administered from one or two vascular points) after the redistribution of arterial blood flow in the liver in patients with hepatic neoplasms and arterial anatomic peculiarities (AAP). Twenty-four patients with liver neoplasms and AAP (graded according to Michel's classification) were included in the study. During pretreatment angiographic planning, all extrahepatic vessels that could feed the tumor were embolized and the intrahepatic vessels occluded in order to redistribute blood flow. The distribution of microspheres was initially assessed by using technetium-99m-labeled macroaggregated albumin ((99m)Tc-MAA) from one of two vascular points before the administration of yttrium-90 ((90)Y)-radiolabeled resin microspheres. Perfusion of lesions situated in the redistributed segments (L-RS) and nonredistributed segments (L-NRS) were compared by assessing the distribution of (99m)Tc-MAA by SPECT/CT. Perfusion was graded as normal, reduced, or absent. (90)Y resin microspheres were then injected from the same arterial sites as (99m)Tc-MAA and the tumor response recorded 3 months later. The tumor response in L-RS was compared with that in L-NRS and graded as better, similar, or worse. Among 11 patients with type I AAP in whom mainly vessels in segments I-III or IV were occluded, perfusion of L-RS was graded as similar (n = 7) or reduced (n = 4). Among the remaining 13 patients with AAP types III (n = 3), V (n = 4), VIII (n = 3), and others (n = 3) in which aberrant arteries were occluded, perfusion of L-RS was graded as similar (n = 9), reduced (n = 3), or absent (n = 1). Overall, (99m)Tc-MAA was present in the L-RS of 95.8% patients and the distribution of (99m)Tc-MAA in L-RS and L-NRS were graded as similar in 66.6% of patients. Compared with lesions in the L-NRS, tumor response in L-RS was similar in 23 cases and worse in 1 case. No complications were recorded after the administration of (90)Y resin microspheres. Redistribution of flow in L-RS is feasible and enables a safe and effective delivery of (90)Y resin microspheres that are able to be distributed via intrahepatic collaterals and access the microvasculature of L-RS.