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Fluoroscopic Radiation Exposure in Chemoembolization and Radioembolization: Results from a Prospective Randomized Study
SPECIAL LETTERS SECTION Fluoroscopic Radiation Exposure in Chemoembolization and Radioembolization: Results from a Prospective Randomized Study From: Ahmed Gabr, MD Joseph Ralph Kallini, MD Robert J. Lewandowski, MD Riad Salem, MD, MBA Section of Interventional Radiology (A.G., J.R.K., R.J.L., R.S.) Department of Radiology, and Division of Hematology and Oncology (R.S.) Department of Medicine Northwestern University 676 North St. Clair, Suite 800 Chicago, IL 60611
Editor: Hepatocellular carcinoma (HCC) accounts for most primary liver cancers, resulting in 740,000 deaths annually (1). Locoregional therapies, including yttrium-90 (90Y) radioembolization and conventional transarterial chemoembolization, are often applied to unresectable HCC. Several studies have been conducted to compare 90Y radioembolization and conventional transarterial chemoembolization in regard to survival outcomes, time to progression (TTP), response, and toxicities. Despite lack of evidence, the need for planning angiography before 90 Y radioembolization has been perceived as “extra radiation” compared with conventional transarterial chemoembolization. We present data regarding cumulative lifetime fluoroscopic radiation exposure and dose received by patients with HCC enrolled in a prospective randomized phase II trial comparing 90Y radioembolization and conventional transarterial chemoembolization (2). With institutional review board approval, 45 patients with early or intermediate HCC were prospectively randomly assigned to conventional transarterial chemoembolization or 90 Y radioembolization as part of the PREMIERE Trial. The primary endpoint was TTP. The results favored 90Y radioembolization, with longer median TTP (> 26 months) than patients in the conventional transarterial chemoembolization group (6.8 months; P ¼ .0012) (hazard ratio 0.122; 95% confidence interval [CI], 0.027–0.557; P ¼ .007). Using available intention-to-treat data in this prospective study, fluoroscopy times and total doses were compared by patient and by treatment. Statistical significance was set at P < .05. Twenty-one patients received conventional transarterial chemoembolization (32 treatment sessions), and 24 patients
R.S. and R.J.L. are both scientific advisors to BTG International Ltd (London, United Kingdom). Neither of the other authors has identified a conflict of interest. http://dx.doi.org/10.1016/j.jvir.2017.05.005
received 90Y radioembolization (29 treatment sessions) with glass microspheres. All patients receiving 90Y radioembolization underwent separate planning angiography before 90Y radioembolization. One patient received coil embolization of the falciform artery to avoid nontarget radioembolization. The median fluoroscopic time of planning angiography was 10.9 minutes (95% CI, 8.5–13), whereas median fluoroscopic dose was 1.2 Gy (95% CI, 0.6–2.4). Planning angiography represented an extra procedure compared with the conventional transarterial chemoembolization cohort. Median fluoroscopy time was 10 minutes (95% CI, 7.6–16.6) for 90Y radioembolization treatment and 15.4 minutes (95% CI, 14.2–19) for conventional transarterial chemoembolization treatment (P ¼ .02). Median fluoroscopic dose was 1 Gy (95% CI, 0.5–1.5) for 90Y radioembolization treatment and 1.6 Gy (95% CI, 1.3–2.1) for conventional transarterial chemoembolization (P ¼ .035). When comparing accumulated fluoroscopy radiation exposure from all 90Y radioembolization and conventional transarterial chemoembolization treatments received by the patients after randomization, including fluoroscopy exposure from 90Y radioembolization planning angiography and cone-beam computed tomography median cumulative fluoroscopy time for conventional transarterial chemoembolization after multiple treatments, length of exposure was 22 minutes (95% CI, 15.3–35.5) for conventional transarterial chemoembolization and 28 minutes (95% CI, 21.7–33.9) for 90Y radioembolization (P ¼ .82). Median cumulative fluoroscopic dose was 2.8 Gy (95% CI, 1.6–5.5) for conventional transarterial chemoembolization and 2.5 Gy (95% CI, 1.9–4.6) for 90Y radioembolization (P ¼ .38). Granular details are provided in the Table. The results of this single-center phase II trial showed that 90 Y radioembolization provided significantly longer TTP; however, both treatments demonstrated similar survival outcomes. The choice between conventional transarterial chemoembolization and 90Y radioembolization may at times be confounded by the assumption that the requirement for planning angiography during 90Y radioembolization will translate into greater lifetime radiation dose. Our observation does not support this contention. 90Y radioembolization with glass microspheres consumes little procedure time and rarely requires prophylactic coil embolization, with single vessel injections and no concern for reflux given microembolic effect (3). In contradistinction, performing conventional transarterial chemoembolization often involves a slow and deliberate injection with magnification view, resulting in longer procedural time and exposure to fluoroscopy. Contemporary techniques now involve a same-day 90Y radioembolization treatment paradigm, further reducing total procedural time as well as patient travel (4). In this paradigm, patients undergo planning angiography, technetium-99m macroaggregated albumin scan, and 90Y radioembolization treatment in a single outpatient encounter, saving patient time and cost. In conclusion, procedural radiation exposure from fluoroscopy is significantly lower in 90Y radioembolization
Volume 28 ▪ Number 9 ▪ September ▪ 2017
Table. Fluoroscopic Exposure in
90
1273
Y Radioembolization versus Conventional Transarterial Chemoembolization Chemoembolization
Radioembolization
Median (95% CI)
Mean (95% CI)
Median (95% CI)
Mean (95% CI)
15.4 (14.2–19) 22* (15.3–35.5)
18.3 (15.3–21) 29.3* (20.7–38)
10 (7.6–16.6) 28* (21.7–33.9)
13.3 (10–16.6) 28.3* (23.7–32.8)
N/A
N/A
P Value
Fluoroscopy Time (min) Per treatment session Cumulative fluoroscopy for all treatments per patient Planning angiography
10.9 (8.5–13)
.02 .82
11.6 (9.3–13.8)
Fluoroscopy Dose (Gy) Per treatment session Cumulative fluoroscopy for all treatments per patient
1.6 (1.3–2.1)
1.8 (1.4–2.3)
1 (0.5–1.5)
2.8* (1.6–5.5)
3.9* (1.8–6.1)
2.5* (1.9–4.6)
N/A
1.2 (0.6–2.4)
Angiography
N/A
1.2 (0.7–1.5) 2.9* (1.9–4)
.035 .38
1.6 (1.0–2.3)
CI ¼ confidence interval; N/A ¼ not applicable. *For patients with available cumulative radiation data.
compared with conventional transarterial chemoembolization. However, intention-to-treat lifetime fluoroscopic radiation exposure is equivalent between patients receiving 90Y radioembolization with glass microspheres and conventional transarterial chemoembolization as a treatment for HCC. Efforts are underway to further reduce procedural time and fluoroscopic radiation exposure using the same-day treatment paradigm.
REFERENCES 1. Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulent J, Jemal A. Global cancer statistics, 2012. CA Cancer J Clin 2015; 65:87–108. 2. Salem R, Gordon AC, Mouli S, et al. Y90 radioembolization significantly prolongs time to progression compared with chemoembolization in patients with hepatocellular carcinoma. Gastroenterology 2016; 151:1155– 1163.e2. 3. Sato K, Lewandowski RJ, Bui JT, et al. Treatment of unresectable primary and metastatic liver cancer with yttrium-90 microspheres (TheraSphere): assessment of hepatic arterial embolization. Cardiovasc Intervent Radiol 2006; 29:522–529. 4. Gabr A, Kallini JR, Gates VL, et al. Same-day 90Y radioembolization: implementing a new treatment paradigm. Eur J Nucl Med Mol Imaging 2016; 43:2353–2359.
Incidence of “Occult” Prostatopudendal Arterial Anastomoses during Prostatic Artery Embolization From: Jeremy I. Kim, MD Hemant Desai, BS Ari J. Isaacson, MD Department of Radiology (J.I.K., A.J.I.) University of North Carolina
From the SIR 2017 Annual Meeting. A.J.I. receives personal fees from BTG (West Conshohocken, Pennsylvania). Neither of the other authors has identified a conflict of interest. http://dx.doi.org/10.1016/j.jvir.2017.02.009
101 Manning Dr. Chapel Hill, NC 27514; and University of North Carolina School of Medicine (H.D.) Chapel Hill, North Carolina
Editor: Complications associated with prostatic artery embolization (PAE) have occurred secondary to inadvertent embolization of the bladder, rectum, seminal vesicles, and penis (1,2). Of these nontarget sites, the penis is of particular concern because of the risk of tissue ischemia or erectile dysfunction. Previous studies of pelvic arterial anatomy have demonstrated prostatic artery anastomoses with the internal pudendal artery in as many as 43.3% of pelvic side anastomoses and with the lateral accessory pudendal artery in as many as 20% (3,4). Occasionally, these pathways are often not visible on initial digital subtraction angiography (DSA) of the prostatic artery, but then become apparent after embolization of the intraprostatic branches. In this study, a review was performed to determine the incidence of these “occult” prostatopudendal anastomoses (PPAs). Retrospective analysis was performed with institutional review board approval. DSA images from PAE procedures performed at a single institution between April 2014 to April 2016 by a single interventional radiologist with 3 years of experience were reviewed. Angiography was performed through a 2.4-F microcatheter (Direxion; Boston Scientific, Marlborough, Massachusetts) placed in the anterior/lateral prostatic artery. Iohexol (Omnipaque 300; GE Healthcare, Waukesha, Wisconsin) was hand-injected at a rate of 0.1–0.2 mL/s through a 3-mL syringe. Tris-acryl gelatin microspheres (Embosphere Microspheres; Merit Medical, South Jordan, Utah) ranging in size from 100 μm to 300 μm were diluted with 9 mL of saline solution and 9 mL of iohexol (GE Healthcare) before embolization. Intraembolization angiography was performed when decreased embolic flow was seen on fluoroscopy. Embolization was performed until stasis was
Editor: Hepatocellular carcinoma (HCC) accounts for most primary liver cancers, resulting in 740,000 deaths annually (1). Locoregional therapies, including yttrium-90 (90Y) radioembolization and conventional transarterial chemoembolization, are often applied to unresectable HCC. Several studies have been conducted to compare 90Y radioembolization and conventional transarterial chemoembolization in regard to survival outcomes, time to progression (TTP), response, and toxicities. Despite lack of evidence, the need for planning angiography before 90 Y radioembolization has been perceived as “extra radiation” compared with conventional transarterial chemoembolization. We present data regarding cumulative lifetime fluoroscopic radiation exposure and dose received by patients with HCC enrolled in a prospective randomized phase II trial comparing 90Y radioembolization and conventional transarterial chemoembolization (2). With institutional review board approval, 45 patients with early or intermediate HCC were prospectively randomly assigned to conventional transarterial chemoembolization or 90 Y radioembolization as part of the PREMIERE Trial. The primary endpoint was TTP. The results favored 90Y radioembolization, with longer median TTP (> 26 months) than patients in the conventional transarterial chemoembolization group (6.8 months; P ¼ .0012) (hazard ratio 0.122; 95% confidence interval [CI], 0.027–0.557; P ¼ .007). Using available intention-to-treat data in this prospective study, fluoroscopy times and total doses were compared by patient and by treatment. Statistical significance was set at P < .05. Twenty-one patients received conventional transarterial chemoembolization (32 treatment sessions), and 24 patients
R.S. and R.J.L. are both scientific advisors to BTG International Ltd (London, United Kingdom). Neither of the other authors has identified a conflict of interest. http://dx.doi.org/10.1016/j.jvir.2017.05.005
received 90Y radioembolization (29 treatment sessions) with glass microspheres. All patients receiving 90Y radioembolization underwent separate planning angiography before 90Y radioembolization. One patient received coil embolization of the falciform artery to avoid nontarget radioembolization. The median fluoroscopic time of planning angiography was 10.9 minutes (95% CI, 8.5–13), whereas median fluoroscopic dose was 1.2 Gy (95% CI, 0.6–2.4). Planning angiography represented an extra procedure compared with the conventional transarterial chemoembolization cohort. Median fluoroscopy time was 10 minutes (95% CI, 7.6–16.6) for 90Y radioembolization treatment and 15.4 minutes (95% CI, 14.2–19) for conventional transarterial chemoembolization treatment (P ¼ .02). Median fluoroscopic dose was 1 Gy (95% CI, 0.5–1.5) for 90Y radioembolization treatment and 1.6 Gy (95% CI, 1.3–2.1) for conventional transarterial chemoembolization (P ¼ .035). When comparing accumulated fluoroscopy radiation exposure from all 90Y radioembolization and conventional transarterial chemoembolization treatments received by the patients after randomization, including fluoroscopy exposure from 90Y radioembolization planning angiography and cone-beam computed tomography median cumulative fluoroscopy time for conventional transarterial chemoembolization after multiple treatments, length of exposure was 22 minutes (95% CI, 15.3–35.5) for conventional transarterial chemoembolization and 28 minutes (95% CI, 21.7–33.9) for 90Y radioembolization (P ¼ .82). Median cumulative fluoroscopic dose was 2.8 Gy (95% CI, 1.6–5.5) for conventional transarterial chemoembolization and 2.5 Gy (95% CI, 1.9–4.6) for 90Y radioembolization (P ¼ .38). Granular details are provided in the Table. The results of this single-center phase II trial showed that 90 Y radioembolization provided significantly longer TTP; however, both treatments demonstrated similar survival outcomes. The choice between conventional transarterial chemoembolization and 90Y radioembolization may at times be confounded by the assumption that the requirement for planning angiography during 90Y radioembolization will translate into greater lifetime radiation dose. Our observation does not support this contention. 90Y radioembolization with glass microspheres consumes little procedure time and rarely requires prophylactic coil embolization, with single vessel injections and no concern for reflux given microembolic effect (3). In contradistinction, performing conventional transarterial chemoembolization often involves a slow and deliberate injection with magnification view, resulting in longer procedural time and exposure to fluoroscopy. Contemporary techniques now involve a same-day 90Y radioembolization treatment paradigm, further reducing total procedural time as well as patient travel (4). In this paradigm, patients undergo planning angiography, technetium-99m macroaggregated albumin scan, and 90Y radioembolization treatment in a single outpatient encounter, saving patient time and cost. In conclusion, procedural radiation exposure from fluoroscopy is significantly lower in 90Y radioembolization
Volume 28 ▪ Number 9 ▪ September ▪ 2017
Table. Fluoroscopic Exposure in
90
1273
Y Radioembolization versus Conventional Transarterial Chemoembolization Chemoembolization
Radioembolization
Median (95% CI)
Mean (95% CI)
Median (95% CI)
Mean (95% CI)
15.4 (14.2–19) 22* (15.3–35.5)
18.3 (15.3–21) 29.3* (20.7–38)
10 (7.6–16.6) 28* (21.7–33.9)
13.3 (10–16.6) 28.3* (23.7–32.8)
N/A
N/A
P Value
Fluoroscopy Time (min) Per treatment session Cumulative fluoroscopy for all treatments per patient Planning angiography
10.9 (8.5–13)
.02 .82
11.6 (9.3–13.8)
Fluoroscopy Dose (Gy) Per treatment session Cumulative fluoroscopy for all treatments per patient
1.6 (1.3–2.1)
1.8 (1.4–2.3)
1 (0.5–1.5)
2.8* (1.6–5.5)
3.9* (1.8–6.1)
2.5* (1.9–4.6)
N/A
1.2 (0.6–2.4)
Angiography
N/A
1.2 (0.7–1.5) 2.9* (1.9–4)
.035 .38
1.6 (1.0–2.3)
CI ¼ confidence interval; N/A ¼ not applicable. *For patients with available cumulative radiation data.
compared with conventional transarterial chemoembolization. However, intention-to-treat lifetime fluoroscopic radiation exposure is equivalent between patients receiving 90Y radioembolization with glass microspheres and conventional transarterial chemoembolization as a treatment for HCC. Efforts are underway to further reduce procedural time and fluoroscopic radiation exposure using the same-day treatment paradigm.
REFERENCES 1. Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulent J, Jemal A. Global cancer statistics, 2012. CA Cancer J Clin 2015; 65:87–108. 2. Salem R, Gordon AC, Mouli S, et al. Y90 radioembolization significantly prolongs time to progression compared with chemoembolization in patients with hepatocellular carcinoma. Gastroenterology 2016; 151:1155– 1163.e2. 3. Sato K, Lewandowski RJ, Bui JT, et al. Treatment of unresectable primary and metastatic liver cancer with yttrium-90 microspheres (TheraSphere): assessment of hepatic arterial embolization. Cardiovasc Intervent Radiol 2006; 29:522–529. 4. Gabr A, Kallini JR, Gates VL, et al. Same-day 90Y radioembolization: implementing a new treatment paradigm. Eur J Nucl Med Mol Imaging 2016; 43:2353–2359.
Incidence of “Occult” Prostatopudendal Arterial Anastomoses during Prostatic Artery Embolization From: Jeremy I. Kim, MD Hemant Desai, BS Ari J. Isaacson, MD Department of Radiology (J.I.K., A.J.I.) University of North Carolina
From the SIR 2017 Annual Meeting. A.J.I. receives personal fees from BTG (West Conshohocken, Pennsylvania). Neither of the other authors has identified a conflict of interest. http://dx.doi.org/10.1016/j.jvir.2017.02.009
101 Manning Dr. Chapel Hill, NC 27514; and University of North Carolina School of Medicine (H.D.) Chapel Hill, North Carolina
Editor: Complications associated with prostatic artery embolization (PAE) have occurred secondary to inadvertent embolization of the bladder, rectum, seminal vesicles, and penis (1,2). Of these nontarget sites, the penis is of particular concern because of the risk of tissue ischemia or erectile dysfunction. Previous studies of pelvic arterial anatomy have demonstrated prostatic artery anastomoses with the internal pudendal artery in as many as 43.3% of pelvic side anastomoses and with the lateral accessory pudendal artery in as many as 20% (3,4). Occasionally, these pathways are often not visible on initial digital subtraction angiography (DSA) of the prostatic artery, but then become apparent after embolization of the intraprostatic branches. In this study, a review was performed to determine the incidence of these “occult” prostatopudendal anastomoses (PPAs). Retrospective analysis was performed with institutional review board approval. DSA images from PAE procedures performed at a single institution between April 2014 to April 2016 by a single interventional radiologist with 3 years of experience were reviewed. Angiography was performed through a 2.4-F microcatheter (Direxion; Boston Scientific, Marlborough, Massachusetts) placed in the anterior/lateral prostatic artery. Iohexol (Omnipaque 300; GE Healthcare, Waukesha, Wisconsin) was hand-injected at a rate of 0.1–0.2 mL/s through a 3-mL syringe. Tris-acryl gelatin microspheres (Embosphere Microspheres; Merit Medical, South Jordan, Utah) ranging in size from 100 μm to 300 μm were diluted with 9 mL of saline solution and 9 mL of iohexol (GE Healthcare) before embolization. Intraembolization angiography was performed when decreased embolic flow was seen on fluoroscopy. Embolization was performed until stasis was