22 Dimensional Versus 3 Dimensional Versus 3 Dimensional (Conformal) Dimensional (Conformal)

Radiation Therapy in the Radiation Therapy in the Management of Operable Left Management of Operable Left

Breast CancerBreast CancerDr.Dr.Mohamed AbdelrahmanMohamed Abdelrahman

Lecturer of Clinical Oncology- Faculty of Lecturer of Clinical Oncology- Faculty of Medicine-Cairo UniverstyMedicine-Cairo Universty

IntroductionIntroduction-Breast cancer is the most common malignancy Breast cancer is the most common malignancy

in women in women (Jemal et al 2006)(Jemal et al 2006)..In Egypt, constitutes In Egypt, constitutes 33% of all female cancer.33% of all female cancer. (El-Bolkoiny, 2000)(El-Bolkoiny, 2000)..

Post-operative Radiation Therapy (PORT) Post-operative Radiation Therapy (PORT) reduces local recurrence.reduces local recurrence.(Pierce et al., 1994)(Pierce et al., 1994)..

But there were reports of a breast cancer But there were reports of a breast cancer cause- specific survival advantage for cause- specific survival advantage for radiotherapy.radiotherapy.( Overgaard et al., 1997 and Ragaz et ( Overgaard et al., 1997 and Ragaz et al., 1997)al., 1997)

Standard tangential breast radiotherapy Standard tangential breast radiotherapy exposes lung and heart tissue to exposes lung and heart tissue to radiationradiation ((Foo et al 1993Foo et al 1993).). Standard Standard mortality ratio for heart disease was mortality ratio for heart disease was 1.62 times higher for irradiated 1.62 times higher for irradiated patients than for the non-irradiated patients than for the non-irradiated patientspatients.. (EBCTCG 2000 &2005 )(EBCTCG 2000 &2005 )..

3D treatment of the left breast has 3D treatment of the left breast has reduced the average excess cardiac reduced the average excess cardiac mortality risk by 50% .mortality risk by 50% . ((Muren et al 2002Muren et al 2002))

Aim of WorkAim of WorkTo compare between To compare between 2 2 dimensional & dimensional & 3 3 dimensional dimensional ((ConformalConformal ) radiation therapy techniques in the ) radiation therapy techniques in the PORT of the left breast cancer following PORT of the left breast cancer following mastectomy or breast conservative surgery as mastectomy or breast conservative surgery as regardsregards

Physical outcomePhysical outcome considering dose distribution considering dose distribution inside the target volume (s) & doses received inside the target volume (s) & doses received by surrounding risk structures specially the by surrounding risk structures specially the lungs & the heartlungs & the heart..

Clinical outcomeClinical outcome considering Local control & considering Local control & toxicitytoxicity..

Patients & MethodsPatients & Methods6060 patients with patients with leftleft breast cancer were recruited in breast cancer were recruited in

this study at (this study at (NEMROCKNEMROCK) during the period from) during the period from::

November 2004November 2004 to to MayMay 20082008 . .

They underwent history takingThey underwent history taking

, ,general & local examination, blood picture , kidney general & local examination, blood picture , kidney function tests , liver function tests, FT3, FT4 ,TSH function tests , liver function tests, FT3, FT4 ,TSH & serum B-HCG pregnancy test if suspected & serum B-HCG pregnancy test if suspected pregnancy, Baseline chest radiograph and pregnancy, Baseline chest radiograph and pulmonary function tests,, Baseline pulmonary function tests,, Baseline echocardiography and Technetium MIBI-Heart echocardiography and Technetium MIBI-Heart scanscan..

Planning (Planning (NEMROCK Unit (B) Protocol)NEMROCK Unit (B) Protocol) *CT scanning

*Delineation of volumes

2D DCRT

**RandomizationRandomization-:-:

After approval of both plans, patients were After approval of both plans, patients were randomized using closed envelope method to randomized using closed envelope method to receive their treatment by either receive their treatment by either 2D2D (group (group AA) or ) or 3D3D conformal radiation therapy (group conformal radiation therapy (group BB). After the end of the course of radiation ). After the end of the course of radiation therapy patients were put on hormonal ttt if therapy patients were put on hormonal ttt if HR+ve & followed for recurrence and HR+ve & followed for recurrence and toxicitytoxicity

ResultsResultsBoth arms were balanced as regarding most of clinico-pathological features

Planning Results (DVH data):Planning Results (DVH data):A) Homogeneity and Coverage of PTVsA) Homogeneity and Coverage of PTVs::

No statistically significant differences were No statistically significant differences were detected for detected for Breast Breast (30patients), (30patients), CWCW (30patients) (30patients) & & SCLN-PTVSCLN-PTV (13 patients).But statistically (13 patients).But statistically significant difference was detected for significant difference was detected for IMN-PTV IMN-PTV (15 patients)(15 patients)..

B) Doses to Risk Organs:B) Doses to Risk Organs:1) Left Lung1) Left Lung::

2D2D3DCRT3DCRTp-valuep-value

V20GyV20Gy20.220.2 ±±- - 5.35.3% % 18.218.2 ±± 5.25.2% % 0.0310.031

D50%D50%190190 ±± 106106 cGycGy

150150 ±± 7878 cGycGy0.030.03

NTCPNTCP0.750.75 ±± 0.50.5% % 0.590.59 ±± 1.581.58% % 0.0140.014

22))HeartHeartOnly D50% was statistically better in 3DCRT (118.6 ± 49.7 cGyOnly D50% was statistically better in 3DCRT (118.6 ± 49.7 cGy vs101.6 ± 41.2 cGy in 2D, p-value =101.6 ± 41.2 cGy in 2D, p-value = 0.033 0.033))

Clinical Results:Clinical Results:A) Local Control & SurvivalA) Local Control & Survival::

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B) Toxicity:B) Toxicity: * * Cardiac ToxicityCardiac ToxicityNO NO difference in grading of cardiac dysfunction (RTOG)difference in grading of cardiac dysfunction (RTOG)

BUTBUT Percentage of Reduction of EF from Baseline in Both Arms (P value = 0.013 for nuclear scanning & 0.051 for echo heart)

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Arm A Arm B

Nuclear scanning

ecchoheart

* *Differences were statistically insignificant REGARDING otherDifferences were statistically insignificant REGARDING other organs related toxicityorgans related toxicity..

ConclusionConclusion3D-CRT spared the left lung from 3D-CRT spared the left lung from receiving higher radiation dose during receiving higher radiation dose during the post-operative radiotherapy with the post-operative radiotherapy with significant less reduction of cardiac EF. significant less reduction of cardiac EF. 3D-CRT should be offered for patients 3D-CRT should be offered for patients who are going to receive IMN who are going to receive IMN irradiation for better coverage of the irradiation for better coverage of the target volumetarget volume..

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