Janice Campbell

Reduction of Metastatic Load to Liver after Intraarterial Hepatic Yttrium-90 Radioembolization as Evaluated by [18F]Fluorodeoxyglucose Positron Emission Tomographic Imaging

PURPOSE To assess the response of hepatic metastases after treatment with intraarterial yttrium 90 radioembolization (ie, use of SIR-Spheres) with use of [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET). MATERIALS AND METHODS Nineteen patients with metastatic cancer to the liver from various solid tumors with progression despite polychemotherapy were included. All patients underwent baseline computed tomography, FDG PET, hepatic angiography, and intraarterial technetium 99 m macroaggregated albumin scan for assessment of lung shunting fraction. Patients were treated with 90Y resin microspheres on a lobar basis and were monitored for 3 months with use of dedicated attenuation-corrected PET. For each patient, regions of interest were drawn along the liver edge to measure total liver standard uptake value (SUV) on axial images, covering the entire liver. Visual estimates were also performed and graded as +1, 0, -1, -2, or -3 for progression, no change, and mild, moderate, and dramatic improvement by posttreatment PET. RESULTS The median absorbed dose for the tumor was 76 Gy. There was a significant overall decrease in total liver SUV after treatment (baseline, 71,134 +/- 38,055; after SIR-Sphere treatment, 59,941 +/- 26,509; P = .028) for the entire group. Visual estimates placed 15 patients (79%) in response categories (-3 to -1) and four patients (21%) in nonresponse categories (0 to +1) for the liver. The percentage change of total liver SUV after treatment in the response group (-19%) was significantly greater and different in direction than that in the nonresponse group (+27%; P = .03). This percentage change was also correlated significantly with the respective visual estimates (r = 0.72; P < .0005) for each individual patient. Three patients had major complications related to hyperbilirubinemia (transient, n = 1; permanent, n= 2). CONCLUSIONS The results suggest that there is significant reduction of hepatic metastatic load as evaluated objectively by PET after 90Y radioembolization for the treatment of unresectable metastatic disease to the liver. 90Y radioembolization provides encouraging results by arresting progression of metastatic cancer to the liver.

Y-90 Microsphere Therapy: Prevention of Adverse Events

OBJECTIVE Thirty-three (33) events that were inconsistent with intended treatment for 471 Y-90 microsphere deliveries were analyzed from 2001 to 2007. METHOD Each occurrence was categorized, based on root-cause analysis, as a device/product defect and/or operator error event. Events were further categorized, if there was an adverse outcome, as spill/leak, termination, recatheterization, dose deviation, and/or a regulatory medical event. RESULTS Of 264 Y-90 Therasphere (MDS Nordion, Ottawa, Ontario, Canada) treatments, 15 events were reported (5.7%). Of 207 Y-90 SIR-Spheres (Sirtex, Wilmington, MA) treatments, 18 events were reported (8.7%). Twenty-five (25) of 33 events (76%) were device/product defects: 73% for Therasphere (11 of 15) and 78% for SIR-Spheres (14 of 18). There were 31 adverse outcomes associated with 33 events: 15 were leaks and/or spills, 9 resulted in termination of the dose administration, 3 resulted in recatheterization for dose compensation, 2 were dose deviations (doses differing from the prescribed between 10% and 20%), and 2 were reported as regulatory medical events. Fifty-five (55) corrective actions were taken: 39 (71%) were related to the manufacturer and 16 (29%) were hospital based. CONCLUSIONS This process of analyzing each event and measuring our outcomes has been effective at minimizing adverse events and improving patient safety.

Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography/Computed Tomography Predicts Extrahepatic Metastatic Potential of Colorectal Metastasis: A Practical Guide for Yttrium-90 Microsphere Liver-Directed Therapy

The objective of this retrospective study was to assess the likelihood of extrahepatic metastases based on tumor metabolic load index (TMLI) for patients with colorectal liver metastases to determine the potential intermediate endpoint of yttrium-90 (Y-90) microsphere liver-directed therapy. Forty-eight (48) patients with colorectal metastatic cancer of the liver who were referred for Y-90 microsphere therapy and F-18 fluoro-2-deoxy-D-glucose positron emission tomography (PET) imaging were included. All patients had baseline computed tomography, hepatic angiography, and planning intra-arterial technetium-99m macro-aggregated albumin scans. Pretreatment PET images were analyzed by visual inspection of extrahepatic metastases and by computer quantification of total liver tumor metabolism. For each patient, regions of interest were drawn along the liver edge to measure total liver standard uptake value on axial images, covering the entire span of the liver. The total liver standard uptake value was then converted by logarithm in equivalent volumes of liver mass to obtain TMLI for comparison. A Levene test for equality of variances and t-tests were used for comparing pretreatment TMLIs of patients with or without extrahepatic metastasis. Discriminant and receiver operating characteristic (ROC) analyses were used to obtain a cutoff value with highest specificity in predicting negative extrahepatic metastasis. There were 21 and 27 patients identified as negative and positive for extrahepatic metastasis, respectively. The TMLI of the group with negative extrahepatic metastasis was significantly lower than that with positive extrahepatic metastasis (10.22 + 0.32 versus 10.74 + 0.57, p < 0.0005). The cutoff TMLI with 100% specificity was found to be 10.65. There was a significant difference in liver tumor load with respect to the presence or absence of an extrahepatic metastatic tumor as evaluated objectively with PET. This leads to the identification of TMLI threshold, below which extrahepatic metastases are unlikely and thus may provide guidance for Y-90 therapy.

Yttrium-90 Infusion: Incidence and Outcome of Delivery System Occlusions during 885 Deliveries.

PURPOSE To evaluate the incidence, cause, and management of delivery system occlusions during yttrium-90 (90Y) microsphere infusions and to identify techniques to prevent occlusions. MATERIALS AND METHODS A retrospective review was conducted of 885 consecutive radioembolization deliveries during 820 procedures (some with multiple deliveries) in 503 patients (mean age, 65 y; 293 male) performed between June 2001 and July 2013 at a single academic tertiary care hospital. Occlusions were reported prospectively, and procedural details were reviewed. Statistical analysis assessed associations between catheter occlusions and patient and procedural characteristics. RESULTS Of 885 90Y microsphere deliveries, 11 resulted in occlusion (1.2%). Five occlusions were associated with contained leakage of radioactive material, and one was associated with a spill. Treatment was completed in the same day in 10 patients; repeat catheterization was required in five patients. One patient returned 1 week later to complete treatment. Occlusions were more frequent with deliveries of resin (11/492; 2.2%) versus glass (0/393; 0%) microspheres (P = .002). Occlusions were more likely to occur within the proximal portion of the delivery apparatus (P = .002). There was no significant relationship with any patient characteristics, and there was no improvement with operator experience. The most common cause of occlusion was resin microsphere delivery device failure. CONCLUSIONS (90)Y microsphere delivery device occlusion is uncommon but does occur with resin microspheres. Understanding causes and how to troubleshoot can limit the incidence and detrimental effects.

5:27 PM, Abstract No. 239 - Yttrium-90 infusion: incidence and outcomes of delivery system occlusions

(HCC) with portal vein thrombosis (PVT). Materials and Methods: From 9/2006-9/2014, a total of 675 patients underwent Y treatment. Of this total, 97 patients (age: 63(57-72) years, male1⁄479, 81%) underwent Y therapy (glass-based1⁄472, resin-based1⁄425) for HCC with PVT. In all cases, the presence of PVT was documented on pre-treatment imaging (within 90 days) and verified by an independent radiologist. All patients were classified as BCLC C. Patients were stratified according to prior treatment, Child-Pugh classification, ECOG performance status, extent of PVT, and AFP levels. Outcome variables included CTCAEv4 clinical and laboratory toxicities at 90 days, imaging response (mRECIST), time-to-progression (TTP), and overall survival. Results: A total of 101 treatments were administered. Clinical toxicities included grade 1/2: fatigue1⁄430%, abdominal pain1⁄428%, nausea1⁄417%, ascites1⁄47%. Laboratory Toxicities included grade 1/2: bilirubin1⁄437%, AST1⁄464%, ALT1⁄446% and grade 3/4: bilirubin1⁄417%, AST1⁄415%, ALT1⁄42%. The 30and 90-day mortality rates were 2% and 18% respectively. Forty patients (41%) had baseline imaging with measurable target lesions according to mRECIST criteria, of which, the objective response and disease control rates were 50% (CR1⁄410%, PR1⁄440%) and 63% respectively. The median TTP was 9.1 (5.4-11.7) months. The median overall survival was 9.3(6.1-15) months. Patients who received glass-based therapy survived a median of 15(8.6-19.5) months while those who received resin based therapy survived a median of 4.1(2.7-6.6) months. Univariate analysis demonstrated improved survival in the following subgroups: glass-based therapy (p1⁄40.001), ECOGo1 (p1⁄40.001), and AFPr400 (p1⁄40.003). Conclusion: Patients with HCC and PVT treated with glassbased therapy survived a median of 15 months while those treated with resin-based therapy had a median survival of 4.1 months. Additional predictors of improved overall survival included ECOGo1 and AFPr400.

SU‐GG‐I‐76: Reduction of CT Field on SPECT‐CT Scans: Impact on Patient Dose and Diagnostic Information

Purpose: To evaluate a process for reducing the CT field of view on SPECT‐CT scans and assess its impact on the diagnostic value of the resultant scan interpretation. Method and Materials: 529 prescribed SPECT‐CT scans were evaluated. The physician determined if the CT field could be reduced by review of the initial planar and SPECTimages. 309 met the physician criteria for CT reduction. The CT techniques were recorded before and after the field reduction. The CT automatic exposure control was used on all scans. The interpreting physician completed a data form indicating clinical information CT added or omitted. Effective doses were estimated using the ImPACT CT Patient Dosimetry Calculator for both the full and limited CT.Radiopharmaceutical effective doses were estimated based on MIRD methodology. Results: 95.5% (295/309) of the limited studies had a reduction in the CT effective dose. The mean full CT effective dose was 2.99mSv (+/− 1.38) per patient. The mean limited CT effective dose was statistically less (p<0.001) at 1.81mSv (+/− 1.28). This calculated to a mean decrease of 1.19mSv (42.5%) with a maximum 4.78mSv reduction. The average decrease in total effective dose was 13.6%. There was no effective dose change in 8 and a slight increase (max of 0.3mSv) in 6 studies. 174 (56.3%) reduced fields eliminated a radiation sensitive organ such as the thyroid, cornea, gonads or breast. 31 CT scans revealed incidental findings. Physicians indicated in 232 cases the CT allowed them to make a more accurate anatomical identification of the physiological process than SPECT alone. There were 5 cases that the reduction omitted anatomical information that could have been helpful. Conclusion: Over half of the SPECT‐CT studies were performed with a limited CT field of view, reducing the patients exposure, yet maintaining diagnostic information and quality of interpretation.