Radiation Safety: How Can We Reduce Risk? Rya n K o hlb re nne r, - PDF document

4/17/2018 Radiation Safety: How Can We Reduce Risk? Rya n K o hlb re nne r, MD Assista nt Pro fe sso r o f Clinic a l Ra dio lo g y Unive rsity o f Ca lifo rnia , Sa n F ra nc isc o Financial Disclosures • No ne 1

4/17/2018 Outline • A. I ntro duc tio n • B. Wa ys to Re duc e Ra dia tio n Do se o F re e o Che a p o E xpe nsive Outline • A. Intr oduc tion • B. Wa ys to Re duc e Ra dia tio n Do se o F re e o Che a p o E xpe nsive 2

4/17/2018 Types of Radiation Risks • Sto c ha stic risks/ e ffe c ts o Re sult fro m c e ll muta tio n o Pro bability inc re a se s with do se o E xa mple s: Ca nc e r, he rita b le g e ne tic de fe c ts (? ) • De te rministic risks/ e ffe c ts o Re sult fro m c e ll de a th o S e ve rity inc re a se s with do se o E xa mple s: Skin b urns (pa tie nts), c a ta ra c ts (o pe ra to rs) Deterministic effects Stochastic effects 3

4/17/2018 Deterministic Effects Cataracts: Deterministic Effect Relevant to Proceduralists 4

4/17/2018 Stochastic Risks by the Linear No ‐ Threshold Model Stochastic Risks ‐ Cancer • E stima te d la te nt pe rio ds o 2-12 ye a rs fo r le uke mia o 20 ye a rs fo r so lid o rg a n tumo rs • Ca nc e rs a sso c ia te d with ra dia tio n e xpo sure o L e uke mia o Bre a st o L ung o GI o T hyro id o Bra in 5

4/17/2018 Outline • A. I ntro duc tio n • B. Ways to R e duc e Your R adiation Dose o F re e o Che a p o E xpe nsive Free 6

4/17/2018 Basics of Radiation Protection • Minimize Usa g e o Be ne fits bo th pa tie nt a nd o pe ra to r o T wo wa ys to minimize usa g e • 1. Ste p o n the pe da l le ss • 2. Whe n yo u do ste p o n the pe da l, b e e ffic ie nt • Ma ximize Dista nc e o Be ne fits o pe ra to r o I nve rse sq ua re la w • E xpo sure de c re a se s with the sq ua re o f the dista nc e fo rm the ra dia tio n so urc e • E .g . Mo ving fro m 1m to 3m fro m so urc e will de c re a se yo ur do se b y fa c to r o f 9 Optimizing Radiation Efficiency • 1. Minimize fluo ro sc o py fra me ra te • 2. Minimize DSA fra me ra te • 3. Use la st ima g e ho ld/ fluo ro c ine sa ve s ra the r tha n DSA • 4. Do n’ t b e la te ra l whe ne ve r po ssib le • 5. Co llima te tig htly • 6. Bring do wn de te c to r to pa tie nt • 7. Minimize ma g nific a tio n • 8. Use we ig ht-b a se d pro to c o ls • 9. Ra ise the ta b le • 10. Audit yo ur do se s 7

4/17/2018 Cheap Protective Aprons • Must b e wo rn a t a ll time s, inc lud ing thyro id shie ld • T ra de o ff o F ull le a d (0.5mm Pb ) o ffe rs b e st pro te c tio n o Alte rna tive s to le a d o ffe r g re a te st c o mfo rt • Optio ns o L e a d o L e a d-lite o L e a d-fre e 8

4/17/2018 Protective Aprons • Sc e na rio o Yo ur ne w 0.5mm Pb -e q uiva le nt le a d-fre e a pro n is se nt to yo ur institutio n a nd a tte nua te s 95% a t 75kV a t a c c e pta nc e te sting . Yo ur pa rtne r’ s 0.5mm Pb full-le a d a pro n a tte nua te s 95% a t 75kV. o Will the y g ive yo u the sa me pro te c tio n? • Usua lly no t…so me time s it’ s no t e ve n c lo se • Ac c e pta nc e te sting o nly a t o ne x-ra y e ne rg y • Do e s no t a c c o unt fo r x-ra ys pa rtia lly sc a tte re d in the a pro n b ut ultima te ly ma ke it thro ug h a t a lo we r e ne rg y Protective Aprons • E vide nc e o Me d Physic s (2013); 40(6): 063902 • T e ste d le a d a nd le a d-fre e a pro ns a c ro ss diffe re nt e ne rg ie s • “0.5mm Pb e q uiva le nt” le a d fre e a pro ns pe rfo rme d a s if it we re 0.37-0.46mm Pb e q uiva le nt • Pe ne tra b ility o f o ne le a d-fre e a pro n a t 60kV wa s 478% hig he r tha n le a d o Me d Physic s (2007); 34(11): 4270-80 • T e ste d le a d a g a inst tin a nd tin+b ismuth, a ll with e q ua l “le a d- e q uiva le nc e ” a t 75 kV • T in+b ismuth a tte nua te d 26-42% le ss tha n le a d, de pe nding o n e ne rg y • T in a lo ne a tte nua te d 41-74% le ss tha n le a d, de pe nding o n e ne rg y 9

4/17/2018 Protective Aprons • E vide nc e o E urRadio l(2005); 15(7): 1477-84 • T e ste d le a d c o mpo site a nd le a d-fre e a pro ns in use a t inve stig a ting institutio n • “Out o f the 41 pro te c tive a pro ns e xa mine d fo r a c tua l le a d e q uiva le nc e , 73% we re o utside to le ra nc e le ve ls, with a c tua l le ve ls in so me a pro ns de mo nstra ting le ss tha n ha lf o f the no mina l va lue s.” Leaded Glasses • T ypic a lly 0.5mm Pb e q uiva le nc e • Ca n b e o rde re d with pre sc riptio n • L ike ly re duc e risk o f c a ta ra c ts o ve r c a re e r • Do wnside s o He a vy o L imite d b y po sitio ning o f he a d 10

4/17/2018 Leaded Glasses • E vide nc e o CVI R (2014); 37(5): 1149-55 • 7.9-10.0x re duc tio n fo r fro nta l e xpo sure • 2.1x re duc tio n unde r c linic a l c o nditio ns (le ft e ye ) o J I nte rv Cardio l(2009); 22(3): 299-307 • 3.0x re duc tio n to le ft e ye unde r c linic a l c o nditio ns • 1.9x re duc tio n to rig ht e ye unde r c linic a l c o nditio ns o Me d Physic s (1980); 7(1): 8-12 • 1.8-2.7x fo r sta nda rd mo de ls • 5.3x fo r wra p-a ro und mo de l Suspended Shields • T ypic a lly 0.5mm Pb e q uiva le nc e • Ce iling -mo unte d with b a ll a nd so c ke t jo int • Po sitio ne d b e twe e n pa tie nt a nd o pe ra to r • Do wnside s: o Ce iling ma y a lre a dy b e c ro wde d (surg ic a l lig hts, mo nito rs) o Ma y b e diffic ult to po sitio n during c e rta in pro c e dure s 11

4/17/2018 Suspended Shields • E vide nc e o CVI R (2014); 37(5): 1149-55 • 5.7x re duc tio n to le ft e ye do se unde r c linic a l c o nditio ns o Cath Cardio vasc I nte rv (2006); 67(1): 18-23 • 19.0x re duc tio n to e ye do se unde r c linic a l c o nditio ns • Minima l e ffe c t o n do se to ha nds Protective Drapes • Ste rile , surg ic a l dra pe s impre g na te d with no n- le a d he a vy me ta l • I ne xpe nsive • Dispo sa b le • Diffe re nt mo de ls fo r use with diffe re nt a c c e ss site s • Disa dva nta g e s Adhe sive b a c king ma y fa il o Va ria b le b e ne fit o 12

4/17/2018 Protective Drapes • E vide nc e Cath Cardio vasc I nte rv (2012); 79(1): 97-102 o • RCT – c o ro na ry a ng io g ra ms via tra nsra dia l a c c e ss • 30 c a se s with RADPAD, 30 witho ut RADPAD • 23% o ve ra ll re duc tio n in o pe ra to r do se E JVE S (2014); 47(3): 268-272 o • RCT – E VAR via fe mo ra l a c c e ss • 18 c a se s with RADPAD, 18 witho ut RADPAD • 49 a nd 55% re duc tio n in do se to o pe ra to r ha nds a nd c he st, re spe c tive ly Am J Cardio l (2011); 108(10): 1408-1410 o • RCT – c o mple x c o ro na ry inte rve ntio ns via tra nsra dia l o r fe mo ra l a c c e ss • 30 c a se s with RADPAD, 30 witho ut RADPAD • 41% o ve ra ll re duc tio n in o pe ra to r do se Expensive 13

4/17/2018 Proprietary Imaging Platforms • Ha rdwa re a nd so ftwa re upg ra de s, ta ilo re d to c o mmo n ima g e ta sks, de sig ne d to re d uc e ra d ia tio n d o se while ma inta ining ima g e q ua lity o I nc re a se d c o ppe r b e a m filtra tio n to re duc e use le ss lo w e ne rg y x-ra ys o E dg e sha rpe ning a lg o rithms o T e mpo ra l a ve ra g ing o Mo tio n c o rre c tio n Siemens: CARE+CLEAR • “Sta nda rd” o n e a c h Artis syste m …b ut yo u will like ly pa y to upg ra de yo ur syste m if ne w do se re duc tio n o pa c ka g e is re le a se d • F e a ture s: o Co ntro l o f fluo ro sc o py ra te 0.5-30 fps o Dyna mic filtra tio n o f x-ra y b e a m de pe nding o n pa tie nt thic kne ss a nd C-a rm a ng ula tio n o I mpro ve me nts in c o ne -b e a m CT o Ma pping o f pa tie nt skin do se • T ra c ks c umula tive do se to diffe re nt a re a s o f b o dy a s pro c e dure pro g re sse s 14

4/17/2018 Philips: AlluraClarity IQ • Add-o n pa c ka g e • F e a ture s: o T a sk-spe c ific ima g e pro c e ssing o Dyna mic filtra tio n o Mo st e xte nsive ly studie d ne w pla tfo rm • E vide nc e o JVI R (2017); 28(8): 1129-1135 • 60% re duc tio n in DAP during ute rine a rte ry e mb o liza tio n o JVI R (2015); 26(9): 1331-1338 • 46% re duc tio n in DAP during T ACE o E JVE S (2015); 50(4): 480-86 • 57-73% re duc tio n during E VAR a nd a o rto ilia c o c c lusive c a se s GE: Blueprint • Add-o n pa c ka g e • F e a ture s: o Custo mize do se se tting s fo r diffe re nt use rs fo r diffe re nt pro c e dure s o De te c to r tha t a uto ma tic a lly po sitio ns de te c to r o ptima lly with re spe c t to the pa tie nt o 15-60 se c o nd fluo ro sc o py pla yb a c k o Co ppe r filtra tio n to e limina te lo w e ne rg y x-ra ys o Do se ma p (simila r to Sie me ns) to de te rmine e xpo sure to diffe re nt a re a s o f the pa tie nt 15

4/17/2018 EVAR Imaging Packages • Ava ila b le fro m e ve ry ma jo r ve ndo r Potential Benefits: ‐ Optimized C ‐ arm angulations ‐ Vessel navigation ‐ 3D dynamic overlay Suspended Shielding System • 1mm thic k le a d a pro n suspe nde d fro m c e iling (Ze ro -Gra vity syste m) • L e a d-a c rylic fa c e shie ld to re duc e e ye e xpo sure • Do se re duc tio n c o mpa re d with sta nda rd le a d L e ft a xilla : 78x lo we r o L e ft e ye : 45x lo we r o Rig ht e ye : 56x lo we r o Go na d: 16x lo we r o www.biotronik.com JVIR 2011; 22(4): 437 ‐ 442 16