disclosures - accuray exchange · nodal dose(eqd2) bowel(eq d2) bowel. bed. tomotherapy (54 gy/27...

Disclosures

• An honorarium is provided by Accuray for this presentation

• The views expressed in this presentation are those of the presenters and do not necessarily reflect the views or policies of AccurayIncorporated or its subsidiaries. No official endorsement by AccurayIncorporated or any of its subsidiaries of any vendor, products or services contained in this presentation is intended or should be inferred.

INCIDENCE OF CANCER CERVIX -570000/YEAR AND DEATHS FROM THE DISEASE -311000/YEAR IN 20184th most common cancer amongst women world wideAge standardized rates are 13.1/100000 women globally (2-75/100000)China &India contributed >1/3 of total cervical cancersAverage age at presentation is 53 years(44-68 years)

Arbyn et al,Estimates of incidence and mortality of cervical cancer in 2018,a worldwide analysis.THE LANCET,Dec 04,2019

Primary prevention-HPV 16 &HPV 18-Responsible for 70-75% of all cervical cancers and 40-60% of its precursors

-Bivalent vaccination provides efficacious protection against infection & precancerous lesions associated with these types-Nonvalent vaccine provides protection against 7 carcinogenic HPV types that are causative factor for 90% of cervical cancers

Secondary prevention-PAP smear and detection of precancerous lesions has been the paradigm of secondary prevention for almost half a century

Joura et al,NEJM.2015;372:711-723IARC-Cervix screening-IARC handbooks of cancer prevention.vol 10.IARC press,Lyon,2005

Indications for Radiotherapy for Cancer Cervix• Radical treatment of locally advanced disease IB2-IVA• Post operative patients with high risk features-

• Stromal invasion-with LVSI• Deep 1/3(T size-Any),Middle 1/3(T>2cm),Superficial 1/3(T>5cm),Middle

or Deep1/3 & No LVSI(T>4cm)• Lympho- vascular space invasion

• Positive margins• Positive lymph nodes• Parametrial invasion

• Sedlis et al,Gynae Oncol,1999:73:177-183

Locally advanced cancer cervix-Stage IB3,IIB,IIIA,IIIB,IIIC,M0

• Pre-EBRT – UPG involving the cervix and vaginal fornices extending to posterior upper vagina, with bilateral parametrial involvement(short of pelvis)

Post-EBRT – Residual (3x4 cms) involving the cervix with bilateral parametrial involvement(Right >> Left)

Central recurrences-

• 20-40% for patients receiving conventional radiation experience locoregional relapse

• Options of treatment include • a)Pelvic exenteration-High morbidity• b)Chemotherapy-Poor control• c)Re-irradiation-SBRT/Brachytherapy

Imaging required for GTV delineation-• Contrast enhanced CT scan of abdomen & pelvis

• Levels defined as per individual patient ,however from L2-L3 to introitus

• Fusion with MRI abdomen/pelvis

• Fusion with PET-CT, if available(can change staging in 20% of advanced cancer cervix cases)

CTV/PTV Guidelines• CTV Pelvic/para-aortic nodes-• Obturator nodes, internal, external and common iliac lymph nodes upto

bifurcation of aorta using blood vessels as a surrogate with a 7 mm margin

• Modify to exclude the bone, psoas muscle, bladder and bowel.• Subaortic presacral nodes to be covered by connecting the nodal areas

either side of S1&S2 with a 10mm strip volume• If nodes are present at aortic bifurcation or at common iliac

vessels(histology/PET-CT/>15mm) most superior extent of nodal volume will be at renal hilum.

• A margin of 2 cm is added above the highest involved lymph node• PTV nodes is CTV nodes +7-8mm

1.Taylor A et al,Mapping of pelvic lymph nodes.Int Jl of Radiat Oncol,Biol,Phys.20052.Bansal et al,J Can Res Ther,2013;9:4,574-582

CTV/PTV guidelines-Tumour

• Gross tumour, uterus and parametria, upper third of vagina (unless there is involvement by disease, then 2 cms margin below the apparent disease).Inclusion of proximal half of utero-sacral ligaments

• PTV-Add 15-20mm margin to CTV anterior /posterior/superior and inferior,7-10mm to lateral extension

• PTV parametria and upper vagina =CTV tumour +7 mm

1.Taylor A et al,Mapping of pelvic lymph nodes.Int Jl of Radiat Oncol,Biol,Phys.20052.Bansal et al,J Can Res Ther,2013;9:4,574-582

Simulation and imaging

• Bladder protocol is followed strictly.• One day before planning CT , laxatives are

prescribed to patient to avoid loaded rectum.• A contrast CECT for planning is done (3 mm

sections)• Advanced cases undergo Whole body PETCECT.• MRI is done in almost all cases with advanced

disease.

Banerjee S,Kataria T et al, Division of Radiation Oncology,Medanta The Medicity,2020

Consensus guidelines for EBRT

GTV= Gross tumor in imaging(MR)

HRCTV= GTV+ cervix.

LRCTV= HRCTV+B/L parametria+ Rest of uterus + 2 cm of distal vagina .

Contouring of GTV and CTV

HRCTV

LRCTV

PTV

ITV

Lim et al, Target volume delineationInt. J. Radiation Oncology Biol. Phys., Vol. 79, No. 2, pp. 348–355, 2011

Yashar et al, Computed Tomography Consensus Clinical Target Volume Contouring for Intensity Modulated Radiation Therapy in Intact Cervical Carcinoma. DOI: https://doi.org/10.1016/j.ijrobp.2016.06.047 Banerjee S,Kataria T et al, Division of Radiation

Oncology,Medanta The Medicity,2020

https://doi.org/10.1016/j.ijrobp.2016.06.047

Generating ITV to account for internal motion• Basic IGRT, standard

margin approach The ITV =LRCTV with the following margins:

• 10-15 mm, anterior-posterior.

• 10 -15mm superior-inferior

• 5 mm lateral.• Distal vagina no

additional margin.• The ITV edited from the

muscle and bony boundaries of the pelvis.

PTV

ITV

HRCTV

LRCTV


PTV and Imaging- our practice.• PTV margin of 5 mm to ITV and elective nodal

volume, with daily image guidance and corrections with soft tissue & bony fusion.

• Daily XVI is done for all patient as image guidance.

• Adaptive planning is rarely done in Cervical cancer cases.


Prescription and Plan evaluation in EBRT

• Prescription: Whole pelvis 45Gy in 25# over a 5 weeks, 5# / week.

• Nodes with Gross disease(More than 1 cm) receive a boost of 54 Gy (with SIB).

• Plan evaluation is aimed at limiting bowel, bladder and rectal, pelvic bone dose.

• We aim to restrict • Rectal D2 cc dose to <75 Gy EQD2,D2cc • Sigmoid <75Gy and • Bladder D2 cc to 90 Gy EQD2 • ( taking both EBRT and Brachy in consideration as per the

EMBRACE trial and ABS guidelines).

Pelvic bones

bowel bladder

Kidney RT/LT

Femoral heads

PTV54

PTV45


Boost to GTVnode.After 50 Gy /25 Fr., a CK boost of 8Gy/ 2 Fr was planned and compared with conventional boost. PTV

45GTV_Node Covered by 95% isodose

Modality Nodal Dose(EQD2) Bowel(EQD2)

BowelBED

TomoTherapy(54 Gy/27 Fr)

54 Gy 50.9 Gy 84.8 Gy

TomoTherapy®+ CyberKnife®(50 Gy/25 Fr+8 Gy/2Fr)

60 Gy 52.7 Gy 87.8Gy


Planning for Brachytherapy• Total treatment duration is about 8 weeks unless patient has

severe haematological toxicities.

• Pre Brachytherapy clinical examination is done.

• In post EBRT cases, if we find residual disease on clinical examination a MRI evaluation (both contrast and T2 sequence) is done.

• Brachytherapy is planned by.– Standard intra cavitary Brachytherapy.– Medanta AOLO applicator. – MUPIT.

Brachy plans

Preparation for Brachytherapy

• Clinical examination is done.• A schematic diagram of HRCTV is drawn on the post EBRT

MRI• No. of Needles and positions is planned• Application is done under GA.• Post application a CT imaging is done.• HRCTV and IRCTV are drawn as per MRI findings &clinical

examination • A dose of 7Gy X 4 fraction is planned to attain HRCTV EQD2

of >85 Gy. Banerjee S,Kataria T et al, Division of Radiation Oncology,Medanta The Medicity,2020

At diagnosis Ca Cervix IIIB : PRE-EBRT-MRI

At Brachytherapy : POST-EBRT-MRI


Post EBRT- Preimplant images

Axial Coronal Sagital


Contouring of Target volume as per GEC-ESTRO/ ICRU 89 guidelines and organs at risk (OARs), including the bladder, rectum, and sigmoid.

HRCTV= Entire cervix + EUA findings at BT.

Haie-Meder C et al, GEC-ESTRO Working Group : Target-volume definition and delineation, Radiother Oncol. 2005 Mar;74(3):235-45.

ICRU Report 89,Prescribing,Recording and Reporting Brachytherapy for Cancer Cervix,Oxford University Press,vol13,No 1-2 2013

At Brachytherapy : Planning CT


Planning - Applicator re-construction


Planning results of Brachytherapy


Clinical Implementation Yellow – 200% , Red – 150 % , Blue – 100%, Violet – 75%


Case of Ca Cervix IIBPost EBRT volumes of • GTV(brachy)• HRCTV(Brachy)• IRCTV(Brachy)were drawn on planning CT and plans were createdCyberKnife® is able to create a pear shaped distribution like real brachytherapy.The coverage of treatment volumes and dose to OARs are comparable.[Only for planning study]

250 %

Brachytherapy(BT) is most conformal form of radiotherapy.SBRT can produce similar dose distribution on planning scans.Clinical data shows SBRT can not replace BT in cancer cervix due to significant better results by BT.

In cases where a BT procedure is impossible, SBRT may be offered after detail discussion.

SBRT is called virtual brachytherapy.

GTV and HCTV adequately covered by 100 percent dose in the planning study.

Indications for SBRT/TomoTherapy• 1. Medical contra-indications to brachytherapy• 2.Anatomical difficulty to ICRT/Interstitial implant• 3.Steep dose gradients to rectum, bladder ,sigmoid and

bowel are possible• 4.Central recurrence• 5.Para-aortic/Pelvic Lymph node boost• 6.Extended field Helical TomoTherapy®• 7.Distant metastases-Oligo metastatic disease-

Lungs/Bone/Brain

• Radiat Oncol , 8, 109 2013 May 2- Brachytherapy-emulating Robotic Radiosurgery in Patients With Cervical Carcinoma-Simone Marnitz.

• **Technol Cancer Res Treat , 15 (6), 759-765 Dec 2016- Stereotactic Radiotherapy in the Retreatment of Recurrent Cervical Cancers, Assessment of Toxicity, and Treatment Response: Initial Results and Literature Review- Antonio Pontoriero 1,

Acknowledgements

• Medanta Cancer Institute• Dr Susovan Banerjee• Dr Kushal Narang• Dr Shyam Bisht• Dr Gargi Sharma

• Mr Venkatesan• Mr Tamil Selvin• Mr K.Dayanithi• Mr Dinesh Kumar

• Accuray India

THANK YOU

disclosures - accuray exchange · nodal dose(eqd2) bowel(eq d2) bowel. bed. tomotherapy (54 gy/27...

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