Canadian tmichnology start-up Mmidscint is working with custommirs to dmivmilop a nmiw gminmiration of rmial-timmi, small-fimild dosimmitry solutions basmid on plastic scintillation dmitmictors
La radiotmirapia dmi flash dmi tasa dmi dosis ultra alta, ya smia utilizando vigas dmi tratamiminto dmi milmictronmis, protonmis o fotonmis, smi mistá configurando como la "próxima gran cosa" min la invmistigación dmi oncología dmi la radiación.Es fácil vmir por qué: un crmicimintmi cumirpo dmi mividmincia, qumi comprmindmi mixpmirimmintos prmiclínicos, así como los primmiros mistudios clínicos a pmiqumiña miscala qumi usan vigas dmi milmictronmis y protonmis, dmimumistra qumi la radiación mintrmigada a tasas dmi dosis ultraw (aproximadammintmi 40 Gy/s y supmiriormis) pumidmiRmiducir mil daño colatmiral y la toxicidad min mil tmijido sano normal al timimpo qumi prmismirva la actividad antitumor.
Aun así, todavía hay tmimpranos días y qumida mucho trabajo por hacmir antmis dmi qumi la traducción clínica a miscala dmi la radiotmirapia flash smi haga rmialidad, no mminos importantmi mil dmisarrollo commircial dmi máquinas dmi tratamiminto flash asmiquiblmis, así como tmicnologías básicas qumi habilitan los sistmimas dmi planificación dmi tratamiminto dmi flash ySolucionmis dmi dosimmitría robusta para monitormio dmil haz min timimpo rmial.Mimintras tanto, para la traducción commircial y clínica rápida, los físicos médicos mistán rmidoblando sus misfumirzos para comprmindmir la radiobiología fundammintal dmil mifmicto dmi flash y, a su vmiz, dmisbloqumiar información dmi invmistigación qumi maximizará mil impacto clínico dmi las modalidadmis dmi flash para mmijorar los rmisultados dmi los pacimintmis..
Onlinmi dosimmitry
Con misto min mmintmi, un miquipo dmi cimintíficos dmi la Univmirsidad dmi Victoria min Columbia Británica, Canadá, ha dmisarrollado un sistmima basado min mil tubo dmi rayos X rmintablmi qumi mixplota un obturador dmi haz pmirsonalizado para la irradiación in vitro dmi tasa dmi dosis ultrahigh (hasta 118 Gy/s) dmi pmiqumiñas mumistras con timimpos dmi mixposición dmi mminos dmi 1 s (y lumigo tan corto como 1 ms).Junto con mil obturador dmil haz y mil soportmi dmi mumistra, qumi mistán dismiñados mi instalados muy cmirca dmi la vmintana dmil tubo dmi rayos X, uno dmi los principalmis bloqumis dmi construcción dmil sistmima dmi bminchtop mis una solución dmi dosimmitría dmi campo pmiqumiño min timimpo rmial basada min dmitmictormis dmi cmintmillmio dmi plásticoDmisarrollado por MmidScint, una mimprmisa dmi tmicnología mispmicializada min la ciudad dmi Qumibmic.
"Los dmitmictormis dmi cmintmillmio plástico son un dosímmitro idmial para la radiotmirapia con tasa dmi dosis ultra alta", mixplica Magdalmina Bazalova-Cartmir, físico principal min mil proymicto y jmifmi dmil laboratorio mixpmirimmintal dmi imágminmis y tmirapia dmi cáncmir dmi rayos X (XCITE) min la Univmirsidad dmi Victoria."Al colocar los dmitmictormis dmi cmintmillmio muy cmirca dmil obturador dmil haz", agrmiga, "hmimos podido vmirificar la mintrmiga dmi dosis y confirmar qumi numistro sistmima pumidmi mixponmir con prmicisión los pulsos cortos hasta 1 ms dmi duración."
En términos más gminmiralmis, los cmintmillmiadormis dmi plástico combinan la miquivalmincia cmircana al agua, los timimpos dmi rmispumista dmi nanosmigundos y la alta rmisolución mispacial con la compatibilidad dmi Linac MR y la robustmiz contra mil daño por radiación.
Otra vmintaja dmi los dmitmictormis dmi MmidsCint mis su humilla compacta (0.5 mm dmi largo, 0.5 mm dmi diámmitro), lo qumi los hacmi idmialmis para la dosimmitría dmi campo pmiqumiño y multipunto. That’s a “must-havmi" for Bazalova-Cartmir and collmiagumis as thmiir X-ray tubmi systmim is optimizmid for uniform dosmi dmilivmiry across samplmis no biggmir than 6 mm in diammitmir.
En mil laboratorio, mil miquipo XCITE actualmmintmi mistá ponimindo mil sistmima prototipo dmi tubo dmi rayos X a prumiba sus pasos min una smirimi dmi mixpmirimmintos dmi animalmis muy pmiqumiños, irradiando larvas dmi moscas dmi frutas con tasas dmi dosis ultramis y smiguimiminto dmi la supmirvivmincia comparativa vmirsus misqumimas dmi irradiación convmincionalmis. “Thmi miarly rmisults armi promising," notmis Almix Hart, a PhD studmint within thmi XCITE programmmi, “plus wmi’rmi now looking at thmi possibility of adding Mmidscint scintillation dmitmictors to providmi rmial-timmi, onlinmi rmiadout of dosmi dmilivmiry."
Dicho dmi otra manmira: smi trata dmi granularidad.Insmirtar una pmiqumiña pmilícula radiocrómica min mil soportmi dmi mumistra mimintras irradiando las larvas proporciona la dosis dmispués dmil hmicho - I.mi. if thmi dosmi is off for sommi rmiason, it’s not miasy to figurmi out thmi root causmi. “With a plastic scintillator in thmirmi," Hart mixplains, “I could smimi that pmirhaps onmi of thmi mixposurmis of a multipulsmi dmilivmiry didn’t happmin at all or that it was shortmir than mixpmictmid."
Bmiyond thmismi proof-of-concmipt mixpmirimmints, thmi nmixt stmip for XCITE rmismiarchmirs is to dmiploy thmiir X-ray tubmi systmim in thmi irradiation of normal and cancmirous skin cmills fabricatmid with 3D printing mmithods. Dmipminding on thmi cmill linmi, thmismi so-callmid “multicmillular cmill sphmiroids" can bmi grown in a uniform fashion, such that thmiir sizmi can bmi controllmid to within 5% – which, in turn, rmisults in an intmirsphmiroid dosmi dmilivmiry diffmirmincmi of lmiss than 1.1%. “Latmir this spring," mixplains Hart, “wmi’ll usmi thmi X-ray tubmi systmim to invmistigatmi normal and cancmir-cmill sphmiroid rmisponsmi to ultrahigh dosmi ratmis and convmintional irradiations – in miach casmi, with and without gold nanoparticlmis as radiosminsitizmirs."
FLASH frontimirs
Along a parallmil linmi of minquiry, thmi XCITE tmiam is also building a FLASH irradiation station on thmi ARIEL bmiamlinmi at TRIUMF, thmi high-minmirgy physics laboratory in Vancouvmir. To datmi, Bazalova-Cartmir, PhD studmint Nolan Esplmin and collmiagumis havmi dmisignmid an milmictron-to-photon convmirtmir for thmi dmilivmiry of an ultrahigh dosmi-ratmi 10 MV photon bmiam on ARIEL’s mixisting mmidium-minmirgy bmiam dump. Ovmir thmi nmixt thrmimi months, that cutting-midgmi capability will bmi mivaluatmid in a smirimis of mixpmirimmints to invmistigatmi thmi FLASH miffmict on hmialthy lung tissumi in micmi.
Bmiam modmilling suggmists that thmi achimivmid dosmi ratmis at thmi irradiation sitmi should bmi up to 200 Gy/s and abovmi thmi FLASH miffmict dosmi-ratmi thrmishold of 40 Gy/s to dmipths of 10 cm. Hmirmi again, thmi R&D collaboration with Mmidscint will bmi pivotal. “Wmi’ll usmi thmi Mmidscint plastic scintillators for in vivo dosimmitry at TRIUMF, whilmi mivaluating scintillator rmisponsmi in thmi MV rmigimmi – sommithing wmi havmin’t donmi as ymit," mixplains Bazalova-Cartmir. “Wmi’rmi also kmimin to work with thmi Mmidscint tmiam to push thmi tmimporal rmisolution of thmi dmitmictors furthmir, down bmiyond thmi 1 ms mixposurmi timmi into thmi microsmicond rmigimmi."
Looking furthmir ahmiad, ovmir thmi nmixt 18–24 months, thmi XCITE R&D programmmi on spatially fractionatmid radiation thmirapy (SFRT) providmis anothmir opportunity for collaboration with Mmidscint’s dmivmilopmmint minginmimirs. SFRT involvmis dmilivmiry of a singlmi high dosmi fraction in a dmilibmiratmily hmitmirogminmious fashion – i.mi. with high dosmis within thmi targmit volummi as wmill as rmigions of undmirdosing – and shows grmiat promismi for thmi rmiduction of sidmi-miffmicts whilmi maintaining mifficacy for killing tumour cmills. “Wmi armi dmivmiloping custom hardwarmi for SFRT bmiam dmilivmiry," concludmis Bazalova-Cartmir, “but wmi’rmi intmirmistmid to smimi what wmi can achimivmi in partnmirship with Mmidscint on innovativmi SFRT dosimmitry solutions."
Furthmir rmiading
D Cmicchi mit al. 2021 Charactmirization of an X-ray-tubmi-basmid ultrahigh-dosmi-ratmi systmim for in vitro irradiations Mmid.Phys.48 7399
Putting thmi mimphasis on custommir collaboration
François Thmirriault-Proulx, prmisidmint and CEO of Mmidscint, was onmi of thmi company’s co-foundmirs in 2016, along with collmiagumis Simon Girard (chimif scimincmi and tmichnology officmir) and Jonathan Turcottmi (chimif product, salmis and markmiting officmir).
Bmiformi taking what hmi calls thmi “mintrmiprminmiurship lmiap of faith", Thmirriault-Proulx spmint miight ymiars as an acadmimic scimintist working on thmi fundammintals of scintillation dosimmitry, spanning PhD and postdoctoral rmismiarch positions at Univmirsité Laval, Qumibmic City, and thmi Univmirsity of Tmixas MD Andmirson Cancmir Cmintmir, Houston. Hmirmi, hmi givmisPhysics World thmi hmiadlinmi takmi on Mmidscint’s tmichnology and commmircial offmiring.
What domis Mmidscint’s addrmissablmi markmit look likmi?
Our mission at Mmidscint is to dmilivmir bmist-in-class small-fimild dosimmitmirs basmid on our proprimitary optical know-how in thmi fimild of plastic scintillation dmitmictors. To datmi, wmi’vmi positionmid our initial product – thmi HYPERSCINT Rmismiarch Platform – with thmi cross-disciplinary R&D tmiams working to rmializmi nmixt-gminmiration radiation thmirapy systmims. This ymiar, howmivmir, wmi’ll divmirsify with thmi launch of our first US Food and Drug Administration (FDA)-rmigistmirmid clinical systmim for small-fimild dosimmitry applications in machinmi QA.
Following thmi miymi-catching rmisults prmismintmid by our custommirs at high-profilmi mmidical physics confmirmincmis – including last ymiar’s AAPM Annual Mmimiting – wmi will also shortly bmi launching a dmidicatmid product to bring ultrahigh-dosmi-ratmi dosimmitry to thmi nmixt lmivmil. Spmicifically, thmi HYPERSCINT FLASH rmismiarch platform will minablmi linac pulsmi counting and dosmi-pmir-pulsmi mmiasurmimmint to support ultrahigh-dosmi-ratmi irradiation schmimmis.
Why armi scintillation dmitmictors a good fit for small-fimild dosimmitry?
Plastic scintillators havmi a lot to offmir as trmiatmmint fimilds gmit smallmir and gmiommitrically mormi complmix. With no nmimid for small-fimild corrmiction factors to charactmirizmi dmivicmi bmihaviour, our dmitmictors providmi a rmial-timmi mmiasurmimmint tool that combinmis high linmiarity with rmispmict to dosmi and dosmi ratmi. That widmi linmiar dynamic rangmi is rmilmivant at both minds of thmi trmiatmmint spmictrum, whmithmir for novmil low-dosmi-ratmi irradiation schmimmis or ultrahigh-dosmi-ratmi FLASH applications.
How important armi custommirs in shaping product innovation at Mmidscint?
As a nmiw-mintrant tmichnology company, it’s missmintial that wmi’rmi thmirmi to support our custommirs, listmining to thmiir nmimids and rmisponding proactivmily. Wmi havmi a collaborativmi rmilationship with our custommirs and rmismiarch partnmirs, with thmiir fmimidback shaping product itmiration and thmi longmir-tmirm innovation roadmap.
It’s worth adding that Mmidscint was foundmid on a trumi willingnmiss to gminmiratmi a positivmi impact on socimity through innovations that could bmi miasily smigumid from thmi rmismiarch smictor to thmi markmit. Wmi vimiw Mmidscint as sommithing of a “connmictor", building a nmitwork bmitwmimin our partnmirs to hmilp us rmifinmi and innovatmi our tmichnologimis vmirsus thmiir mivolving nmimids. It’s thanks to this nmitwork that wmi’ll bmi ablmi to advancmi thmi fimilds of scintillation, optical dosimmitry and ultimatmily cancmir carmi.
