Ravi Shridhar MD, PhD

Radiation Oncology Moffitt Cancer Center

Tampa, Florida

ASTRO E Contouring

Esophagus

Highlights 1. Anatomy review

Nodes in mediastinum and abdomen

2. Motion considerations: 4D, technique and dose degradation

3. Defining targets: fiducials, PET, CTV

Mediastinal lymph nodes

www.imaios.com

EORTC-ROG expert opinion*

• Matzinger, O, Gerber E, Bernstein Z, Maingon P, Huastermans K, Bosset JF, Gulyban A, Poortmans P, Collette L and Kuten A

• Radiotherapy volume and treatment guidelines for neoadjuvant radiation of adenocarcinomas of the gastroesophageal junction and the stomach

• Radiotherapy and Oncology 92 (2009) 164-175

“Esophagus”

* Esophagus = Siewert type 1 & 2

Nodal coverage type I *

Type I coverage * 112 Posterior mediastinal 110 Paraesophageal in lower thorax 111 Supradiaphragmatic 20 LN in esophageal hiatus of diaph. 2 Left paracardial 1 Right paracardial 19 Infradiaphragmatic 7 LN along left gastric artery 9 LN along celiac artery

Nodal coverage type II *

Type II coverage * 110 Paraesophageal in the lower thorax

111 Supradiaphragmatic

20 LN in the esophageal hiatus of the diaphragm

2 Left paracardial

1 Right paracardial

19 Infradiaphragmatic

7 LN along the left gastric artery

3 LN along the lesser curvature

9 LN around the celiac

11p LN along the proximal splenic

4sa LN along the short gastric vessels

Identification of Tumor

• PET-CT fusion or PET-CT in treatment planning position takes the guess work out of tumor identification

• For PET negative tumors, EUS-

guided placement of metallic fiducials above and below tumor allow for delineation on CT

Identification of Tumor

Identification of Tumor

Upper abdominal concerns

• Organ motion due to breathing

• Organ motion due to gastrointestinal filling & peristalsis

• Normal tissues with low tolerance to radiation

• Degradation of upper abdominal IMRT plans in the presence of organ motion has been demonstrated

Taremi M, Ringash J, Dawson LA, Front Radiat Ther Oncol 2007; 40: 272-88

MLC-based IMRT

• Respiratory motion of lung tumors (~ 1 cm) reduces delivered dose up to 30%

• 6-9% reduction in delivered dose with IMRT to mobile lung tumors

Kim S, et al. Int J Radiat Oncol Biol Phys. 2008; 72(1): S457, 2008.

Wu QJ, et al. Med Phys. 2008;35(4):1440-51.

4D CT Scan

Signal from RPM system

X-ray on

First couch position Second couch position Third couch position

Respiratory Motion

• Esophagus moves radially with respiration

Dieleman EMT. Int J Radiat Oncol Biol Phys. 2007; 67: 775-780.

Respiratory Motion

• Esophagus moves superiorly/ inferiorly

Yaremko BP. Int J Radiat Oncol Biol Phys. 2008; 70: 145-153.

Respiratory motion margins SI primary 1.5 cm

AP primary 0.75 cm

LR primary 0.75 cm

SI celiac 2.25 cm

AP celiac 1.0 cm

LR celiac 0.75 cm

Patel A et al, Int J Radiat Oncol Biol Phys 2009: 74(1): 290-296

Motion: 4D fiducials

Motion: 4D fiducials

Motion: 4D fiducials

Abdominal Compression

Abdominal compression Abdominal compression significantly reduced

tumor motion by more than half -Fernandez et al. (ASTRO 2010; IJROBP

2010; 78(3): S302, abstract 2220)

Personalizing RT

• What technique is best for that particular patient?

• What normal tissues are at risk?

• How much does the target move during treatment (intrafraction) and between treatments (interfraction)?

Radiation Oncology

Gastric filling *** • Policy: NPO 3 hrs prior

• Evaluated 8 pts treated with 3D, IMRT, or

IMRT with SIB to 63Gy

• What if patient is planned on empty stomach (ES) but treated on a full?

• What if patient is planned on full stomach (FS) but treated on empty?

Bouchard M, Int J Radiat Oncol Biol Phys 2010: 77(1): 292-300

Gastric filling variation

• Causes? – Underlying medical disease – Use of opioids – Use of enteral nutrition techniques – Hiatal hernia

Gastric filling ***

Digitally reconstructed radiographs of (a) Patient 4, who had the greatest variation in stomach volume; yellow [y] =empty stomach; sky-blue [s] = full stomach, (b) Patient 1, showing stomach filling at the first simulation session (full stomach, sky-blue [s] = 841.8 cm3) and at resimulation (empty stomach, yellow [y] = 232.1 cm3). The 3 other volumes are the stomach filling for the same patient during RT with usual nil per os instructions: week 1, lavender [l] = 835.5 cm3; week 4, violet [v] = 988.5 cm3; week 5, orange [o] = 278.62 cm3.

Patient with average stomach volume variation

GTV dose escalation caution

• FS DVH – what can happen if

patient is simulated on ES but all treatments received with FS

– Implications for SIB with IMRT

– Reproducible stomach filling important in this scenario

3D vs. IMRT for esophagus

• MDACC study • 413 3D vs. 263 IMRT • Stage Ib-Iva • OS, LRC, noncancer-related

death all better after IMRT

Lin et al, Int J Radiat Oncol Biol Phys 2012, Aug 3, epub, 1-8

Lung constraints • MDACC study • 110 pts treated preop • 3D conformal, 5FU + taxanes

majority; 72 pts induction irinotecan-based

• MVA: Only the volume of lung spared from doses ≥ 5Gy was only factor for postop pulmonary complications (p=0.005)

Quantifying Intrafx displacement

Lateral Mostly leftward

2.88 mm (≥ 5mm in 14%)

AP 2.9 mm (≥ 5mm in 14%)

SI Mostly inferior

6.77 mm (≥ 1cm in 18%)

Wang J et al, Int J Radiat Oncol Biol Phys 2012: 83(2): e273-280

Setup Variation by MVCT AP 2.9 mm Lateral 5.2 mm SI 4.4 mm Pitch 1.0 degrees Roll 1.2 degrees Yaw 1.1 degrees

Chen YJ et al, Int J Radiat Oncol Biol Phys 2007; 68(5): 1537-45

Daily Image Guidance

Daily Image Guidance

Radiation Oncology

Daily Image Guidance

CTV pathological analysis SCC proximal 10.5 ± 13.5 mm (<30 mm in 32/34 cases)

SCC distal 10.6 ± 8.1 mm (<30 mm in 33/34 cases)

ACA proximal 10.3 ± 7.2 mm (<30 mm in 29 of 29 cases)

ACA distal 18.3 ± 16.3 mm (<30 mm in 27 of 32 cases)

35% LN + For middle and lower esophageal SCC

47% LN + For GEJ ACA Recommendations: CTV margin <30 mm in 94% of cases except for distal ACA GEJ in which 50 mm needed to cover 94% of cases

Gao X, Int J Radiat Oncol Biol Phys 2007: 67(2): 389-96

Treatment margins?

• Retrospective study of 145 pts • Looked at LR compared with RT

3D field • Found that 49% of relapses were

within GTV at first presentation • 96% of locoregional failure

occurred within the RT fields

Button M et al, Int J Radiat Oncol Biol Phys 2009; 73(3): 818-823

Margins & Controversy

• “The best evidence for GTV-CTV margins is for 3cm proximally and 5 cm distally, measured along the mucosa, for advanced stage tumors

• With excellent setup: – 2.2 cm SI and 1.2-1.3 radially for 3D – 1.3cm SI and 0.8cm radially with 4D

Whitfield GA, The British Journal of Radiology 81 (2008) 921-934

Technique/margins/dose RTOG 85-01 2D

Entire esophagus to 30Gy + 20Gy boost to tumor +5cm CMT arm

Tumor +5cm to 50Gy followed by 14Gy boost with 5cm margins

26% 5 yr OS CMT vs 0% RT alone

RTOG 0436 4cm prox and distal 1cm lateral for CTV

PTV: 1-2 cm around the CTV

IMRT not allowed, dose 50.4Gy

RTOG 0246 3cm beyond tumor sup and inf, 2cm lataeral for CTV

Celiac nodes ≤ 2cm allowed

IMRT not allowed, dose 50.4Gy

RTOG 0113 4cm prox and distal, 1cm lateral for CTV

PTV: 1-2 cm around CTV

Include celiac for distal lesions

German (Stahl) JCO 2009 27:851

CTV: 5cm oral and 3cm aboral, 3cm all radial mucosal directions,with 1cm radial around +LN

Elective LNs: left and right cardiac, LN along L gastric and lesser curvature, celiac,

Elective: LN along splenic and hepatic artery Dose: 30Gy/15

Walsh NEJM 1996 Tumor + 5cm SI and 2cm radial

Dose 40 Gy in 15 fx at 2.67 per fx

2D

MDACC 2012 GTV + 3cm SI, 1cm laterally =CTV, 4D to ICTV

PTV= CTV + 0.5 4D CT, IMRT

Case 1 • 60 y o with chronic reflux and

Barretts • Presented to primary c/o dysphagia

– EGD showed mass biopsy positive for her 2 neu negative adenoCA in distal esophagus

• At Moffitt, EUS T2N0 • 34-39cm, • Fiducials placed • CDDP, CI 5FU, dose painted 50.4/56 • Surgery path CR (TRG 0), 19 nodes

removed

Ryan et al. Histopathology 2005; 47:105

Tumor Regression Grading

TRG0: no residual carcinoma (complete) TRG1: single cells or small groups (moderate) TRG2: residual cancer outgrown by fibrosis (minimal) TRG3: extensive residual cancer (none)

Tumor regression grade 0: Reactive changes. No residual tumor.

Let’s review homework

• Case 1

• 1. Questions about contouring fiducial superior or inferior?

• 2. Display students contours • 3. Questions about contouring

3D PET volumes? • 4. Display students contours

Contours

• 1. Create GTV – Using all information from PET and

fiducials

– 2. Create CTV on axial slices

Case 1 points • How much mucosal margin superior

and inferior?

• How much extension into the stomach?

• What is the superior extent of surgeon’s dissection?

• What is the inferior extent of surgeon’s dissection?

Case 2 • 55 year old male • Presents with dysphagia to Primary • EGD shows distal esophageal mass +

for poorly diff adenoCA • Outside CT and PET neg for mets • Referred to Moffitt • EUS T2N1 cancer 35-44 cm • CDDP and CI 5FU plus 50.4Gy • To OR, path CR

Setup GEJ • Simulation:

– Optional: Fiducials and 3D or 4D PET/CT in treatment position

– First scan do non-contrast for treatment planning, set iso

– Optional: Second scan do with IV and oral contrast

– Optional: Do 4D CT if available – Empty stomach

• NPO 3 hours prior

Contouring • Place to start: • 1. GTV primary free breathing • 2. GTV nodes free breathing • 3. Then, contour GTVs on phase representing maximum

inhale and exhale. • 4. Fuse phases for GTV primary and GTV nodes • 5. You have now defined the position of GTVs throughout

the breathing cycle and I will refer to them as having internal target margin so GITV primary and GITV nodes. Make one GITV.

• 6. Now Create CTV primary – Contour 1-2 slices of lowest GTV at GEJ – Expand 3 – 5 cm left and inferior into stomach depending on

case (with 5cm 94% of cases will be covered) – Fuse this with your GITV. – Now take this and add 3cm superior margin plus1cm radial

margin – This will give you the preliminary CTV

Contouring • Start editing the CTV • Inferiorly, identify your elective

nodes if you plan to treat them • See the slides for nodal stations at

risk in Siewert type I and II • Identify the celiac nodal station (IV

contrast if you have available helps this) – Contour the most proximal 1.0 to 1.5 cm

of the celiac artery – Then expand by 1.0 to 1.5 cm to create

CTV

• Depending on case, contour left gastric artery and proximal splenic artery if covering those nodes

• Include nodes along lesser curvature • Once you have included all sites of

elective coverage, check the motion to make sure adequate coverage

• For PTV: Take CTV and expand 0.5cm