How IMRT is changing since itsfi t i It lHow IMRT is changing since itsfi t i It lfirst use in Italyfirst use in Italy

October 21-22, 2011University of Modena and Reggio EmiliaUniversity of Modena and Reggio Emilia

CLINICAL EXPERIENCES WITHCLINICAL EXPERIENCES WITH TOMOTHERAPY AT HSRTOMOTHERAPY AT HSR

NADIA DI MUZIONADIA DI MUZIO

TOMOTHERAPY  PROTOCOLS  AT  HSR

SITE STAGE INDICATIONSCHEDULE

n fractions Gy / f

H&N IVa/bradical 30 1.8-

2.15(2.25)

dj 30 1 8 2 3adjuvant 30 1.8-2.3

LUNG IIIa/b radical 25 2.5

PANCREAS III radical 15 > 3.2

pT2-T4pN0 adjuvant 20 2.9PROSTATE

T1-T3 radical 28 1.85-2.65

LUNG MTS max 3 < 3cm radical 6 > 6LUNG MTS max 3 , < 3cm radical 6 > 6

LIVER MTS max 4 , < 3cm radical 5 > 8

RETREATMENTS var radical var var

TomoTherapy :

work-flow at HSR

CT +

PET HN, lung, pelvis

NMR b i l iNMR brain, pelvis

4D-PET/CT lung, pancreas, liver

SPECT lungg

Contouring BTV/GTV and OARs

Planning strategy:

Constraints related to dose/fraction value

Patient dosimetry: Part of QC. Critical cases

Daily MVCT-KVCT match

treatment

Up to 20% of patients are excluded from radical 

RT treatment because of unsuspected metastasesPET

Lardinois et al. 2003

Schrevens et al 2004

Impact of the motion on PET images : Lung Study

PET SUVBASAL:  2.0BIN1: 2 6

BASAL BIN‐ 1 BIN‐ 2

BIN1:      2.6BIN2:      2.3BIN3:      2.5BIN4: 3 2BIN4:      3.2BIN5:      2.9BIN6:      2.5

BIN‐ 3 BIN‐ 4 BIN‐ 5SUV =: SUVbw(g/ml)

BIN‐ 6 HSR‐Milano

Impact of the motion on PET images: Liver Study

“St ti ”“Static”PET 4D‐PET

SUVPhase 6=3.1SUV=1.8

“Static”

4D‐PETPET

SUVPhase 1=2.9SUV=1.6

SUV =: SUVbw(g/ml)HSR‐Milano

RPM Respiratory Gating™ System

TM : Varian  Medical System Gating School Copenhagen

4D Data Sorting

Patient Breathing Curve

X‐ray ONPET acquisition 

CT or PET Images Phases

Goal:Define the target volume and the volume of space that encompasses tumor motion.

4D-PET/CT CONTOURING

st

BTV

exp

insp sum

HSR , Milan

4D-PET/CT CONTOURING

ITV ITV

HSR , Milan

SIMULTANEOUSSIMULTANEOUS 

INTEGRATED 

BOOSTBOOST

TARGET DOSETARGET DOSE

Intermediate risk Intermediate risk

VolumesVolumes Low risk NCCNLow risk NCCN

Intermediate risk Intermediate risk NCCN NCCN

Roach formula Roach formula <15%<15%

HighHigh risk NCCNrisk NCCNRoach formula Roach formula ≥≥ 15%15%

D/frD/fr DtotDtot D/frD/fr DtotDtot D/frD/fr DtotDtot

PTVPTV11PTVPTV11(LN+P+VSI)*(LN+P+VSI)* 1.851.85 51.851.8 1.851.85 51.851.8

PTVPTV22(P+VSI)(P+VSI) 22 5656 2 22 2 61 661 6 2 342 34 65 565 5PTVPTV22(P+VSI)(P+VSI) 22 5656 2.22.2 61.661.6 2.342.34 65.565.5

PTVPTV33(P+(P+ VSVS11//33)) 2.22.2 61.661.6 2.342.34 65.565.5 2.652.65 74.274.2

PP TVTV44 (P)(P) 2.552.55 71.471.4 2.652.65 74.274.2 2.652.65 74.274.2

PP OVERLAPOVERLAP 2.342.34 65.565.5 2.342.34 65.565.5 2.342.34 65.565.5

TOMOSIB ( + LN )

PTVPBowelsout of N

Femoral headOverlap

Rectum PTV SVFemoral head

PTV LN

60 pts median follow up : 47.2 months ( 34.2- 60.1 m)

ACUTE TOXICITYACUTE TOXICITYRESULTSRESULTS

4550

484225G0

UGI 29/60

LGIGURTOG

303540

GU12(5)1821G1

484225G0

202530 GU

LGI(rectum)UGI

002G3

0012G2

51015

05

G0 G1 G2 G3

100 pts median follow up : 40.7 months (18.4-60.1 m)

ACUTE TOXICITYRESULTS

70

80

RTOG GU LGI UGI

G0 35 71 7250

60

GUG0 35 71 72

G1 38 28 25

30

40GULGI(rectum)UGI

G2 25 1 3

G3 2 0 0 10

20

0G0 G1 G2 G3

60 pts median follow up : 47.2 months ( 34.2‐ 60.1 m)

LATELATE TOXICITYTOXICITYRESULTSRESULTS

50

60

605148G0

UGI 29/60

LGIGURTOG

40

50

GU076G1

605148G0

20

30GULGI(rectum)UGI

002G3

024G2

10

20

0G0 G1 G2 G3

100 pts median follow up : 40.7 months ( 18.4- 60.1 m)

LATELATE TOXICITYTOXICITYRESULTSRESULTS

60

70

6957G0

LGIGURTOG

40

50

2223G1

6957G0

30

40GULGI(rectum)

05G3

915G2

10

20

0G0 G1 G2 G3

DFS median follow up 40 m (17 57 months)DFS median follow up  40 m (17‐57 months) 

97%

PANCREATIC CANCERHypofractionated Tomotherapy with concomitant 

h th i d d ti d ichemotherapy in advanced pancreatic adenocarcinoma. Preliminary results of a phase I study.

ENDPOINT

To determine the radiotherapy MTD to tumor sub volume infiltrating vesselsTo determine the radiotherapy MTD to  tumor sub‐volume infiltrating vessels

METHODS

44 patients in stage III or IV previously CT‐treated 

Simulation performed with contrast enhanced 4D CT/PETSimulation performed with contrast‐enhanced 4D‐CT/PET

GTV1: the tumor, and 

GTV2:  a tumor sub‐volume 1 cm around infiltrated vessels 

were contoured on 4D‐CT.

MATERIALS AND METHODSMATERIALS AND METHODSMATERIALS AND METHODSMATERIALS AND METHODS

• ● From June 2005 to November 2008

• ● 44 pts (♀. 23; ♂. 11)

SIB GROUPSIB GROUP: : 2525 ptsptsPTV2PTV2 44.25 44.25 GyGy/15 f. +/15 f. +

SIBSIB withwith dose escalationdose escalation toto PTV1PTV1• ●Median age: 60 ys (40‐74)

• ●Median KPS : 90 (60‐100)

SIB SIB withwith dose escalation dose escalation toto PTV1 PTV1 (48 (48 GyGy: 4 : 4 ptspts, 50 , 50 GyGy: 6 : 6 ptspts, ,

52 52 GyGy: 3 : 3 ptspts, 55 , 55 GyGy: 6 : 6 ptspts, 58 , 58 GyGy 7 7 ptspts))ed a S : 90 (60 00)

• ● Adenocarcinoma: 44

II d ti CHT 29 di N° f l 6

c.i.c.i. 5FU / CAPECITABINE 5FU / CAPECITABINE 5-FU 250mg/m2/day c i in the first 6 pts• ● IInduction CHT 29 pz, mmedian N° of cycles : 6 

(2‐11)• (PEXG: 11, PDXG: 8, PEFG: 6, GEM: 3, 

CDDP+GEM: 1)

5 FU 250mg/m2/day c.i. in the first 6 pts. 23 remaining pts received capecitabine, 1250 mg/m2/day

• ● Stage: III 23 pts, IV 3 pts (2 pts with CR ofhepatic metastases, 1 pt with stable disease 6 months after the end of CHT), local relapse 3 pts No SIB GROUP: 19 No SIB GROUP: 19 ptspts

44 2544 25 GG /15 f PTV (/15 f PTV (PTV2PTV2))44.25 44.25 GyGy /15 f. PTV (/15 f. PTV (PTV2PTV2))

MATERIALS AND METHODSMATERIALS AND METHODS

volumes Definition:

SIB GROUPSIB GROUP Non SIB GROUPNon SIB GROUP

GTV in 4 series of 4D CT

GTV in 4 series of 4D-CT4D-CT 4D CT

GTV2GTV2 GTV1GTV1GTV2GTV2(tumor)(tumor)

GTV1 GTV1 (infiltrated vessels (infiltrated vessels + 5+ 5--10 mm)10 mm)

ITV=ITV1ITV=ITV1boolean Union

ITV2ITV2 ITV1ITV1

ITV=ITV1ITV=ITV1boolean Union

4D4D--PTV2PTV2 4D4D--PTV1PTV14D4D--PTV=4DPTV=4D--PTV2PTV2

0.5-0.5-0.7 cm

Volume definition:Volume definition:

Pancreatic Tumour: two 4D‐PTV

4D‐PTV24D PTV1 4D PTV2 

(44.25 Gy, 15 fr)

4D‐PTV1 

“Vascular region ” 

(48 58 Gy 15 fr)(48‐58 Gy, 15 fr)

STST‐‐PTVs 3DCRT vs 4DPTVs 3DCRT vs 4D‐‐PTVs 3DCRTPTVs 3DCRT

ST‐PTV vs 4D‐PTC: GEOMETRIC RESULTS

4D‐PTVs were smaller than ST‐PTVs in all pts

4D‐PTVs were 36% smaller than ST‐PTV (mean value 187 cm3 vs 295 cm3 p=0 0006)cm3, p=0.0006)

Overlapping volumes between 4D‐PTVs and stomach was 59% smallerpp gthan overlapping volumes between ST‐PTVs and stomach (mean value 7 vs 18 cm3, P=0.0014)

Overlapping volumes between 4D‐PTVs and duodenum was 43% smallerthan overlapping volumes between ST PTVs and duodenum (mean valuethan overlapping volumes between ST‐PTVs and duodenum (mean value 9 vs 16 cm3, P=0.006)

STST‐‐PTVs 3DCRT vs 4DPTVs 3DCRT vs 4D‐‐PTVs 3DCRTPTVs 3DCRT

3DCRT TargetsOrgan DVH

ParametersST-PTV(MeanV l )

4D-PTV(MeanV l )

OrganSpared

(%)

P

Values) Values) (%)

Stomach D mean 22 6 17 6 22% 0 007Stomach D_meanV20V50

22.648.513,9

17.639.78.3

22%18%40%

0.0070.010.004

Duode-num

D_meanV20

35.069.9

30.163.4

24%9%

0.010.01

V50 36.1 25.3 29% 0.01Kidney D_mean

V209.0

18 56.9

13 223%28%

0.030 05V20

V3018.511.2

13.27.7

28%31%

0.050.06

3DCRT vs TOMOTHERAPY

Target = 4DPTVs

Organ DVHP t

3DCRT( )

TOMO( )

OrganS d PParameters (Mean values) (Mean values) Spared

(%)P

Stomach D mean 17 6 16 5 8% 0 36Stomach D_meanV20V50

17.639.78.3

16.529.24.3

8%29%48%

0.360.0040.001

Duode-num

D_meanV20

30.163.4

24.650.5

17%20%

0.0030.001

V50 25.3 12.7 49% 0.001Kidney D_mean

V206.913 2

13.318 0

-48%26%

0.00060 16V20

V3013.27.7

18.01.2

-26%84%

0.160.01

Pancreatic Tumour: HT plan

Dose distribution two 4D‐PTV 

PANCREATIC CANCERRESULTS

DOSE LEVELS:

I level, 48 Gy: 3 ptsI  level, 48 Gy: 3 ptsII  level, 50 Gy: 6 ptsIII  level, 52Gy: 3 ptsIV level 55 Gy: 6 ptsIV  level, 55 Gy: 6 ptsV  level, 58 Gy: 7 pts 

G3 TOXICITYG3 TOXICITY:

Gastric ulcer: 1 pt at the II level

Gastro‐duodenitis: 1 at the IV level

COMMENTS:COMMENTS:The planned final dose to PTV1 was 58 Gy

RESULTS:TOXICITYRESULTS:TOXICITYEarly toxicity

SIB Group N°Pts (%) Non SIB Group N° Pts(%)

Diarroea G1 3 ( 20%) 5 (12% )

Diarroea G2 2 ( 13%) 2 (15%)

Nausea e vomiting G1 5 ( 33%) 5 ( 28%)

N i i G2 3 (1 %) 9 (20%)Nausea e vomiting G2 3 (15 %) 9 (20%)

Nausea e vomiting G3 0 ( 0%) 1 (4% )

Anorexia G1 3 (13%) 1 (7% )

Anorexia G2: 1 ( 6%) 1 (7% )Anorexia G2: 1 ( 6%) 1 (7% )

Abdominal pain G1 2 (13%) 0 ( 0%)

Abdominal pain G2 3 (20 %) 5 ( 38%)

Weigth loss G1 1 ( 6%) 0 ( 0%)Weigth loss G1 1 ( 6%) 0 ( 0%)

trombocitopenia G1 1 ( 6%) 1 (7% )

Neutropenia G2 0 (0%) 2 (15%)

Hepatotoxicity G1 2 (13%) 2 ( 15%)

E l T i it G3 t i l i SIB G 1/25 ti t (4%)

Hepatotoxicity G1 2 (13%) 2 ( 15%)

Hepatotoxicity G2 1 (6%) 0 (0%)

●● Early Toxicity G3: gastric ulcer in SIB Group : 1/25 patients (4%) ●● LateLateToxicity: hemorragic gastro-duodenitis G3 in Non SIB Group : 1/19 pz (5%)

“Common Terminology Criteria for Adverse Events (CTCAE)” v 3.0‐NCI‐ 2003.

RESULTS: RESPONSES CT/RESPONSES PETRESULTS: RESPONSES CT/RESPONSES PET

RESPONSES SIB Group No SIB Group 29 / 44 pts

CT PET

RESPONSES SIB Group (24/25 pts)

No SIB Group (19/19 pts)

29 / 44 pts

PR 4 pts (17%) 3 pts (16%) 20 pts (68%)

CR 0 pts (0%) 1 pts (6%) 3 pts (10%)

SD 17 pts (70%) 11 pts (58%) 4 pts (15%)

PD 3 pts (13%) 4 pts (20%) 2 pts (7%)p ( ) p ( ) p ( )

RESULTS: SITES OF FIRST PROGRESSIONRESULTS: SITES OF FIRST PROGRESSION

Local + systemic: 23/44 (53%)l l / ( )Local only: 4/44 (10%)

Median TTP : 12 2 mMedian TTP : 12 2 mMedian TTP : 12.2 m. Median TTP : 12.2 m. Median TTLP: 16.2 m. Median TTLP: 16.2 m. Median OS : 18 6 mMedian OS : 18 6 mMedian OS : 18.6 m.Median OS : 18.6 m.

Time to progression

44

Time to local progression

44

Overall Survival

44

PANCREATIC CANCERPANCREATIC CANCERPANCREATIC CANCERPANCREATIC CANCER

A dose of 44.25 Gy in 15 fractions on PTV2 concomitant to 5-FU c.i. or oral capecitabine is feasible and effective ( mild rate of toxicity)capecitabine is feasible and effective ( mild rate of toxicity) .

Th i b i fil d l d i hThe concomitant boost to infiltrated vessels does not seem to improve the response rate; however, once the maximum tolerated dose to the tumor sub-volume is reached, its efficacy will be tested on potentially operable disease.

The sequence of induction chemotherapy followed by chemoradiationseems to allow the best long term survival resultseems to allow the best long term survival result

DOSEDOSE

ESCALATION

DOMINANT  INTRAPROSTATIC  LESION (DIL)

Mounting evidence that radioresistant cells and/or high‐clonogen density volumes may bevolumes may be concentrated in one or more local foci [Cellini 2002] , named “dominant intra‐prostatic lesions” (DIL)

Intraprostatic IMRT boosting under DCE‐MRI and MRST guidance

Van Lin et al2006

Intraprostatic IMRT boosting under DCE‐MRI and MRST guidance

Van Lin et al.,2006

DIL dose escalation by Tomotherapy: Planning study design at HSRPlanning study design at HSR

• DIL defined by T2WI + diffusion weighted (DWI) MRIdiffusion weighted (DWI) MRI

• PTV DIL = DIL + 5mmPTV DIL   DIL   5mm

• Increasing the dose to PTV‐DIL i 28 f i IGRTDIL in our 28 fractions IGRT scenario (71.4 Gy to prostate) with Tomotherapy

PTVDIL

• N=7 patients

PTVDIL71,4 Gy; 2,55 Gy/fr (EQD2=75 Gy)80 Gy; 2,86 Gy/fr (EQD2=86 Gy)

PTV(p+sv)71 4 G 2 55 G /f

y; , y/ ( Q 2 y)90 Gy; 3,21 Gy/fr (EQD2=99 Gy)100 Gy; 3,57 Gy/fr (EQD2=113 Gy)120 Gy; 4 29 Gy/fr (EQD2=143 Gy)*71,4 Gy; 2,55 Gy/fr 120 Gy; 4.29 Gy/fr (EQD2=143 Gy)*

EQD2 calculated with α/β=10

PTV‐DILD il li IGRT (MVCT)• Daily on‐line IGRT (MVCT)

• Minimization of prostate shape deformation through dailyMinimization of prostate shape deformation through daily rectal enema; rectum emptying procedures if full rectum at daily MVCT [Fiorino IJROBP 2008]

• Residual “safe” margin (IGRT system uncertainty, intra‐fraction, contouring) = 5 mmfraction, contouring)   5 mm

Example of post‐MVCT emptying procedure1° SCAN 2° SCAN

(1 h ft )(1 h after)

Constraints‐ Rectum constraints: 

‐ Bladder constraints:

V75 < 0.1 cc

Constraints

V80 < 0.1 cc (EQD2=94Gy)

V75 (EQD2=85Gy) < 1 cc

“As low as possible” out PTV

‐Femoral heads

BRA

V70 (EQD2=77Gy) < 2 cc

V68.5 (EQD2=75Gy) < 5%

Dmax < 40 Gy

‐Urethra

CHY

V65.5 (EQD2=70Gy) < 20%

V40 < 60%

V90 < 0.1 cc

‐ Bulbus of the penis

Y

V52<50%

EQD2 calculated with α/β 3α/β=3

Results (Patient with large overlap b PTV DIL d )between PTV‐DIL and rectum)

P+SV = DIL = 71 4 G

Step 0

71.4 Gy

P+SV = 71.4 Gy DIL= 80 Gy

Step 1

y

P+SV = 71.4 Gy yDIL= 100 Gy

Step 3

DIL

RectumPTV‐DIL

PTV

BladderF. Heads

urethra

Preliminary conclusions

Ultra‐high dose escalation (EQD2 > 110 Gy) on DIL definedUltra high dose escalation (EQD2 > 110 Gy) on DIL defined by T2WI‐DWI MRI should be feasible 

Tomotherapy guarantees   target coverage, maintaining a 5 mm margin while respecting the constraints on OARs (in particular no significant increase of rectal NTCP is expectedparticular, no significant increase of rectal NTCP is expected compared to conventional dose delivery)

DIL theorem + availability of powerful IMRT/IGRT tools + predictive NTCP = rationale for future clinical pstudies….ΔTCP evaluations in progress….

A Clinical Phase I‐II study should start within the year

RECTAL CANCERRECTAL  CANCER

PURPOSETo test the clinical feasibility of adaptive RT concomitant to oxaliplatin (oxa) and 5FU c.i. in rectal cancer. 

BACKGROUND: ANALYSIS OF RECTUM VOLUME VARIATION DURING TOMOTHERAPY

• The rectum was retrospectively contoured on the daily Megavoltage images (MVCT) of six patients previously treated with Tomotherapy. The variations of rectum volume during Tomotherapy were examinedTomotherapy were examined.

• Rectal volume shows a linear decrease of  58.2 % between the start and end of the treatment (range: 28.6%‐75.4%); most of the rectum volume variation was observed in the first half of th t t t ith d ti f 50%the treatment with an average reduction of 50%.

• A first estimate of optimized margins for  adaptive RT with concomitant boost to the tumour was achieved by expanding the rectal contouring during the initial MVCT s and subsequently d i h d h lf f h i h diff i (0 5 0 7 1 1 5 2 )during the second half of the treatment with different margins (0.5, 0.7, 1, 1.5, 2 cm).

• In the second half of the treatment, more than 90% (range: 82.4%‐100%) of the rectal volume union was contained within a margin of 0.5 cm, while a margin of at least 1 cm is necessary to obtain the same coverage in the first part of the treatment.

• Based on the results of this investigation, a pilot adaptive approach was started in which aBased on the results of this investigation, a pilot adaptive approach was started in which a concomitant boost is delivered on the last 6 treatment fractions.

PATIENT CHARACTERISTICSPATIENT CHARACTERISTICS

• N° of patients treated: 12 (F:4, M: 8)• Median age: 54 years (37‐77)• Median KPS: 100• Eligibility criteria : histologically proven adenocarcinoma, 

li i l t T3 T4 T ith N iticlinical stage T3‐T4 or anyT with N positive• Clinical stage: 

T3N+: 7 ptsT3N+: 7 pts T4N0: 3 pts (anal canal infilration) T4N+: 2 pts (cervical and vaginal infiltration : 1 pt; anal canalT4N+: 2 pts (cervical and vaginal infiltration : 1 pt; anal canal infiltration: 1 pt)

• Distance of tumor from anus ≤6 cm/> 6 cm: 6/6 pts

MATERIALS AND METHODS♦ Simulation and contouring: ‐ after positioning on Comby‐fix®,  patients underwent a contrast‐enhanced CT and MRI simulation; both examinations were repeated after 10 Tomotherapy fractions. ; p py

♦ PTV1: CTV (mesorectum and regional lymph‐nodes) with a margin of 0.5 cm.

♦ ‐ PTV2: residual tumour visible on the intermediate MRI/CT with a margin  of 0.5 cm, taking rectal deformation into account.

♦ Prescription dose: ‐ 41.4 Gy in 18 fractions, 2.3 Gy/fr, to PTV1.dose escalation consisted of a concomitant boost on PTV2: 2 7 Gy/fr (3 pts) 2 9 Gy/fr (9‐ dose escalation consisted of a concomitant boost on PTV2: 2.7 Gy/fr (3 pts), 2.9 Gy/fr (9 pts) on the last 6 fractions.

♦ Concomitant ChT: Oxaliplatin (100mg/m2) on day ‐14, 0 (the start of RT), +14, 5‐FU ♦ Co co ta t C O a p at ( 00 g/ ) o day , 0 (t e sta t o ), , 5 U(250mg/m2/day c.i.) from day ‐14 to the end of RT.

♦ All patients completed RT with a median treatment time of 24 days, and all received 100% of ChT dose.

DOSE DISTRIBUTION WITH TOMOTHERAPY

PTV1 PTV2

RESULTS

i iAcute toxicity (NCI‐CTC‐v3)

Acute ToxicityAcute Toxicity G1G1--G2G2diarrhoeadiarrhoea 45%45%diarrhoeadiarrhoea 45%45%

tenesmustenesmus 45%45%

rectal bleeding rectal bleeding 27%27%

dermatitisdermatitis 27%27%

No G3 acute toxicity occurred

RESULTS

♦ N° of patients undergoing surgery 11/12 pts♦ N° of patients undergoing surgery: 11/12 pts

♦Median time from RT to surgery: 13 weeks (10‐19)

♦ Type of surgery: ‐ LAR: 8 pts‐Miles: 2 pts‐ The youngest pt (37 y) with initial minimal infiltration of anal canal (T4N0) achieved complete remission, refused the operation, and is still free from 

i h f h d f hprogression 16 months after the end of the treatment.

♦ Response:‐ CR: 3/12 pts (25%)‐ Downstaging: 8/12 pts (67%)‐ SD: 1 pt (8%)p ( )

OUTCOME OF SURGERY Clinical Clinical

stagestageType of surgeryType of surgery ResponseResponse TRGTRG Residual cell

vitality

1 T3N1 LAR T2N0 3 1%

2 T4N0 Miles pCR 4 -

3 T4N0 No surgery cCR3 T4N0 No surgery cCR - -

4 T4N0 LAR pCR 4 -

LAR+hysterectomyand bilateral 5 T4N2 salpingo-oophorectomy T4N0 3 20% 6 T4N2 Laparoscopic Miles T3N0 3 5%

7 T3N2 LAR T1N0 3 <5%7 T3N2 LAR T1N0 3 5%

8 T3N1 LAR T2N0 3 5%9 T3N2 LAR T3N1 3 1 % 10 T3N1 LAR T3N1 2 50%

11T3N1 LAR T3N0 3 1 mm from radial

margin

12 T3N2 LAR T3N0 3 focal residual

RECTAL CANCERRECTAL  CANCER

• The estimation of rectal volume variation gives the possibility to better guide d f l h lirradiation for preoperative treatment. In particular the tumour volume 

reduction and the possibility to decrease the PTV margin in the second half of the treatment could allow an escalation of tumour dose using SIB adaptive t t i ith d d i f th T t f th b tstrategies with reduced margins for the T component of the boost. 

• This “adaptive” approach seems to be feasible and well tolerated: no G3 acute toxicity occurred in the 12 pts treated. 

CONCLUSIONSCONCLUSIONS

Tomotherapy offers:

• Great versatility in dose modulation

• Efficacy in SIB delivery

• Good possibility to irradiate targets in motion

• Possibility to perform adaptive radiation therapy and focalPossibility to perform adaptive radiation therapy and focaldose escalation (thanks to IGRT)