Skin Tech

Question 1

Adjuvant dose fractionation for melanoma?

Answer 1

50 Gy in 20 fractions of 2.5 Gy given in 4 weeks. 60 Gy in 30 fractions given in 6 weeks

Question 2

Palliative dose fractionation for melanoma?

Answer 2

8 Gy in a single fraction. 20 Gy in 5 daily fractions of 4 Gy given in 1 week. 36 Gy in 6 fractions of 6 Gy once weekly given in 6 weeks.

Question 3

Whole brain fractionation for melanoma?

Answer 3

12 Gy in 2 daily fractions given on consecutive days. 20 Gy in 5 daily fractions of 4 Gy given in 1 week.

Question 4

What are the treatment options for BCC and SCC?

Answer 4

Surgery
Cryosurgery
Electrodessication& curettage
Moh’smicrographic surgery
Widelocalexcision
Skingrafting
Lymphnodedissection
Topicalchemotherapy
Photodynamictherapy (PDT)
Radiationtherapy

Question 5

What is cyrosurgery?

Answer 5

Smallsuperficiallesions LiquidN2spray Tissuedies,scabformsanddropsoff Cost‐effective Mayrequire>1session Notsuitablenearorganssuchastheeye

Question 6

What is ElectrodessicationandCurettage?

Answer 6

Electrodessicationburns tumour
Tumourthen‘scraped’away
Electricneedletocauterise& killmargin
Mayneedrepeating2‐3times
Goodcosmeticoutcome
Safe&welltolerated
Applications:
Smalllesions(<0.5cm‐95% success)
Multiplelesions

Question 7

What is Mohs Micrographic surgery?

Answer 7

Specialisedandhighlyeffectivetechnique DrFredericMohs(1930s)UniversityofWisconsin Microscopicexamination Permitsimmediate&completemicroscopicexaminationof removedcanceroustissues,soroots&extensionofcancercan beeliminated Normaltissueisspared Highestreportedcurerates

Question 8

What are the advantages of Mohs?

Answer 8

Cancers‐deceptivelylarge‐“roots”inskin,(bloodvessels/nerves/cartilage) Recurrenceskincancers‐sendoutextensionsdeepunderscartissue Techniquespecificallydesigned‐removecancersbytracking&removingthese cancerous“roots” Impossibletopredictpreciselyhowmuchskinwillhavetoberemovedpriorto surgery Finalsurgicaldefect‐slightlylargerthantheinitialcancer Removesonlycanceroustissue,sparingnormaltissue

Question 9

What are the indications for Mohs?

Answer 9

Cancersthathaverecurredfollowingprevioustreatment,or forcancersthatareathighriskforrecurrence Thenose,eyelids,lips,hairline,hands,feet,&genitals Typically‐outpatientprocedure Patientsareawake Discomfortisusuallyminimal&nogreaterthan‐more routineskincancersurgeries

Question 10

What is wide local excision and why do you use it?

Answer 10

Forincompleteexcisionorinadequate margins Mayrequireskingraft Localorgeneralanaesthetic

Question 11

What is topical chemotherapy?

Answer 11

5FU(fluorouracil)orImiquimodcreams Homeapplication,2x/d,~3w Steroidcreamsaddedifnecessary(for swelling)

Question 12

What is photodynamic therapy?

Answer 12

Hypersensitisingcellstolight Injectionortopicalapplicationofdrug(5‐ALA) Laserthenkillscells Outpatientprocedure Keepcoveredanddryfor~36h Scabformsandfallsoffin~3weeks Mayneedrepeattreatmentforthicklesion

Question 13

What are the advantages of surgery?

Answer 13

Quick,Safe
Canhavegoodcosmeticresult
Doesn’trequiremultiplehospitalvisits
onlywaytoproducecompletespecimenforpathologist
Forlargertumoursinvolvingcartilage,bone–risk ofradionecrosis ishigh!
LesionsthatrecurafterRT
UsuallySCCneedswiderexcisionduetopossiblelymphaticspread
Treatmentofchoicefornodalinvolvement

Question 14

What are the distadvantages of surgery?

Answer 14

Generalanaestheticforlargetumours Skingratingmaybenecessarywithlessacceptablecosmetic result Riskofpost‐opcomplications Difficultsites(i.e.innercanthusofeye)–best avoidedsince: damagemayoccure.g.tonasolacrimalduct Reconstructioncanbeverydifficult

Question 15

What are the indications for radiation therapy?

Answer 15

Patientswhoaremedicallyunfitforsurgeryorananaesthetic
Cosmesisi.e.theface
Preservefunction–lower eyelid,lip,nose,innercanthus
Largesuperficialtumourswhere
Extensivesurgeryrequiredforminorclinicalproblem(surgerygives poorercosmeticresult)
Surgerywouldcausemajorlossoffunctione.g.mouthdribbling, numbness,eyelidectropion
Mutilationwouldbeinvolved–e.g. earamputation,nasectomy
Patientspronetokeloid
Recurrence
Positivemargins
Nodaldisease
Perineuralinvasion(spreadalonganerve)or lymphovascularinvasion

Question 16

What are the contradictions for RT?

Answer 16

Youngage(scarisoftenlessnoticeablethantheshapeoftheRTfield whichmayincludeareasoftelangiectasia.Thereisalsotherisk secondarymalignancy,fibrosis)
Previousirradiation
Areapronetotraumae.g.overbonyprominencei.e.shin,backofhand
Uppereyelid
Gorlin‐Goltzsyndrome(patientlikelytodevelopmanytumours)

Question 17

What is superficial treatment and when is it used?

Answer 17

Superficialtreatment
Superficial(kVphotons) Usefulforsmalltumours Frailpatients ImportantRTdepartmentstocontinuetoprovideaccess Newprivatecentresopening Electron HDRBrachytherapy(Esteya)

Question 18

What is the fractionation for SXRT?

Answer 18

36 Gy in 8 fractions of 4.5 Gy given in 17 days treating M/W/F. 30–32 Gy in 4 fractions of 7.5–8 Gy given in 2–4 weeks (one or two fractions/week). 18 Gy in a single fraction.

Question 19

What immobilisation is used?

Answer 19

Positionsupine,prone,decubitus,semiprone,seated
Headrestspillowssandbagsusedifrequired
Formostpatientsbolus/ricebagscanbeusedto supportthepatientandimmobilisethetreatment area.
Forlesionsontheheadandneckacastmaybeused.

Question 20

What are the steps in clinical mark up and why is it important?

Answer 20

Recordenoughinformationtoensuresetupisreproducible. Usuallynottattooed–especiallyifontheface Tracingrequired–includingoutlineoffieldandit’s relationshiptosurfacelandmarks Photosofthetreatmentareaandpatientposition Makesureitiswelldocumented

Question 21

What shielding is used?

Answer 21

Thicknessdependsonenergyused
4mmforelectronsupto10MeV
Individualcut‐outsrequiredforsmalllesions– especiallyifclosetocriticalstructures.
LMPAcutoutinsert
Secondaryx‐raysabsorbedinlead
Waxmaybeaddedtoprovidebuild‐uptodoseatskin
Extraprotectionneededforeyes/nasalcavity

Question 22

What 2 techniques are used for electrons?

Answer 22

Directfield(fixedangles)–usedifwewant toavoidcriticalstructuresormatchto anotherfield Skinapposition(bestcontact)–angles mayvaryfromdaytoday,duetopatient positioningontreatmentcouch.

Question 23

What are the advantages of electrons?

Answer 23

Varyingenergy Canreachcertaindepthdoses–dependingonenergy Rapidfalloffatdepth Cantreatlesionsnearbone&cartilage

Question 24

What are the disadvantages of electrons?

Answer 24

Difficulttomatchfieldsduetobowingisodosecurves–treatmentareais greaterthanthatseenontheskinsurface Notpossibletotreatfieldsizeslessthan4cm

Question 25

What is the electron fractionation of SCC for <5cm and >5cm lesions?

Answer 25

Lesions<5cmindiameter
45Gyin9#(5Gy/#)givenonalternatedaysover3weeksor
54Gyin20#(2.7Gy/#)daily
Lesions>5cmindiameter
Canalsouse50‐54Gyin20#or66Gyin33#

Question 26

What is the post op electron fractionation for SCC?

Answer 26

PostopXRTdoses
50Gyin20#
60Gyin30#

Question 27

What is the side effects of treatment?

Answer 27

Acute: erythema dryitchyskin, dry/moistdesquamation Chronic: pigmentation,telangiectasia, ischaemia,thickening

Question 28

What fractionation for keloid scars and when is it given?

Answer 28

Following surgical excision Radiation therapy is indicated within 24-72 hours post surgery 6 -9Gy/1#

Question 29

What is some alternative therapies for NMSC?

Answer 29

Black Salve Cansema