Post mastectomy or lumpectomy irradiation of the chest wall or breast is common

practice to minimize the local recurrences. Chest wall irradiation is a complicated technical

procedure as the pathological target volume involves the normal structures like lung, heart, and

head of humerus, esophagus and trachea known as organ at risk. The aim of this study was to

verify the cases of the conventional tangential field technique among the breast cancer patients

from year 2006 to 2011. In this study, the previous data of breast cancer patients treated with

radiation from 2006 to 2011 were evaluated. Conventional 2D planning was done by taking body

contour of the patient. Tangential verification films were taken in patients where excess of lung

volume was suspected. The data was analyzed to verify the real lung volume irradiated. From a

total 112 patients underwent tangential verification films during that period, 33% of patients

underwent breast conservative surgery (BCS) while the rest underwent mastectomy. The depth of

the field from the skin to 90% isodose ranges from 2.0 to 8.0 cm. However, 15 (13.4%) out 112

patients needed a replanning. As a conclusion, from 112 cases, the numbers of re-plan cases for

year 2006 to 2011 were only 13 (11.61%) which is less than 15%. This result can be used by the

centre who no dot have the facilities for simulation to verify the depth dose in 2D planning

Bhavaraju, VMK

Mazurawati, M

Nik Ruzman, NIb

Nor Shazleen, AS

Reduan, A

Repository@USM

Reduan et al. 2013 Health and the Environment Journal, 2013, Vol 4, No 2 pp 115-126 115  Tangential Film Verification for Lung Volume Involvement in Breast Cancer Radiation Treatment: East Coast Malaysia Experience  Reduan A a*, Mazurawati M b, Bhavaraju VMK b, Nik Ruzman NIb , Nor Shazleen AS a.  a School of Health Sciences, USM, Kubang Kerian b Dept of Nuclear Medicine, Radiotherapy and Oncology, School of Medical Sciences, USM, Kubang Kerian   ABSTRACT: Post mastectomy or lumpectomy irradiation of the chest wall or breast is common practice to minimize the local recurrences. Chest wall irradiation is a complicated technical procedure as the pathological target volume involves the normal structures like lung, heart, and head of humerus, esophagus and trachea known as organ at risk. The aim of this study was to verify the cases of the conventional tangential field technique among the breast cancer patients from year 2006 to 2011. In this study, the previous data of breast cancer patients treated with radiation from 2006 to 2011 were evaluated. Conventional 2D planning was done by taking body contour of the patient. Tangential verification films were taken in patients where excess of lung volume was suspected. The data was analyzed to verify the real lung volume irradiated. From a total 112 patients underwent tangential verification films during that period, 33% of patients underwent breast conservative surgery (BCS) while the rest underwent mastectomy. The depth of the field from the skin to 90% isodose ranges from 2.0 to 8.0 cm. However, 15 (13.4%) out 112 patients needed a replanning. As a conclusion, from 112 cases, the numbers of re-plan cases for year 2006 to 2011 were only 13 (11.61%) which is less than 15%. This result can be used by the centre who no dot have the facilities for simulation to verify the depth dose in 2D planning.  Keywords: Breast cancer, radiotherapy, mastectomy, tangential field, lung volume, breast conservative surgery        Reduan et al. 2013 Health and the Environment Journal, 2013, Vol 4, No 2 pp 115-126 116  Introduction  Breast cancer is the second most common cancer throughout the world, and is the most common cancer in women, according to the World Health Organization (WHO) . In 2006, Breast Cancer was the most common cancer among female and the most important cancer among population regardless of sex in Peninsular Malaysia (Malaysian Cancer Statistics, National Cancer Council Malaysia (MAKNA). There were 3525 female breast cancer cases registered in National Cancer Registry (NCR) for that year, accounted for 16.5% of all cancer cases registered.   Surgery in the form of mastectomy or breast conservation surgery (BCS) is the one choice of treatment for the breast cancer patients depending on operability and the stage of the disease. In worldwide, women with stage I and II breast cancer usually undergo the breast conserving surgery. Then, the patients need radiotherapy and chemotherapy as adjuvant treatment following the surgery. Radiotherapy plays an important role in the local control of the disease and axillary lymph node recurrence.   The treatment planning for the breast cancer treatment is the most complex and difficult to execute in daily treatment (Figure 1). The common technique used in breast cancer treatment is tangential field technique. The main advantage of this technique is less time consuming and short waiting period for starting the treatment. Besides that, various complex techniques such as CT planning, 3D CRT, IMRT planning was also in practice in selected centers. However, most of the techniques were time consuming and need special equipment for the execution of treatment. The important consideration while planning is how to match the fields to avoid the hot spot inside the target area and reduce dose to normal structures like lungs, heart, and head of humerus, trachea, and esophagus and opposite breast. This study will be a reference for the center without the latest facilities for CT simulation planning and the center which their work load is more for doing the verification routinely.   Figu The majofield of rof the lunlung voluby Shah 6.6% whcase of  medial astochastire 1: The dir limiting fadiation. Asg will definme which iet al. (2008)ich is 0 to 3BCS for a pnd lateral tac effect at magram of conactor in the  the chest witely come is equivalent proved tha.3 Gy in carescribed dngential beore than 20Hventional b and lumpectreatment oall along winto the field to approximt, the dose tse of mastecose of 45 Gams for a li Gy3. A stuealth and the Ereast treatmtomy (BCSf breast cancth inter cost. However, ately 20%o ipsilateral tomy whiley at 2 Gy pnear accelerdy done by nvironment Jouent planning) cases. er is the inal muscles fwe cannot in of lung vollung tissue  0% to 13.5er fraction ator (6 MVNielson et aReduan et arnal, 2013, Vol  process forvolvement oorms the taclude moreume. A preirradiated v4% which i,five fractio) as regardl., (2003) cl. 2013 4, No 2 pp 11 mastectomf the lung irget volume than 3 cm ovious study aried from 0s 0 to 6.77 Gns a week u to possibilioncludes tha5-126117 y n the , part f the done % to y in sing ty of t the   best predlung distto the podirectly cand 0.5%are irradi20 % of breast mare differ            F Material This retrScience, of breast  ictor for theance (CLD)sterior partorrelated to/mm for theated using 3the lung voade the CLDent. igure 2: Mes ospective stHospital Uncancer radio percent of . CLD is the of the ante the percen right lung. cm as a malume was i for each basurement oudy was caiversiti Saintherapy treaHipsilateral lu perpendicurior chest wt-irradiated  It was also ximum for Crradiated. Treast is difff lung volumrried out ats Malaysia ted patientsealth and the Eng volume lar distanceall throughlung volumemeans that LD. For Che differenterent and fue involvem the Radiot(HUSM) ba from year 2nvironment Joutreated by t from the p the isocen which is 018% of left LD is less th of thicknerther dose ent from tanherapy Depsed on the p006 to 2011Reduan et arnal, 2013, Vol angential fieosterior tangtre (Figure .6%/mm folung and 15an 3 cm, it ss for BCS received by gential verartment, Screvious dat. l. 2013 4, No 2 pp 11lds is the ceential field 2) .The CLr left breast% of   rightis mean lessand mastec sensitive orification filmhool of Mea from 112 5-126118 ntral edge D is  lung  lung  than tomy gans .   dical cases   Methods Conventiprocess. lateral wtreatmenta physici From themastectoverificatiinvolvem(Figure 3RE-PLANsurface to  Figure 3technique  onal treatmeImportant inas taken. Th planning cost (Figure 3) planning, my cases, foon film werent. Central). For CLD  procedure 90% of iso: The distan for breast cnt planningformation se patient’s bmputer sys. the depth fr patient wie taken in th lung distanless than 3 c was carriedose line lece from skinancer treatmH was done buch as separody’s contotem and trearom skin suth depth of ese cases, tce (CLD) wm, the treatd out. In css than 3 cm to 90% isoent. ealth and the Eased on patation of the ur was tractment basedrface to 90skin to 90%hey were suas measurement was acase of mast, the treatmedose line mnvironment Jouient’s body body for aned and the i on tangent% of isodo isodose linspected to gd from the dcepted but ectomy patnt planningeasurementReduan et arnal, 2013, Vol contour froterior-posternformation ial techniquse line wae more thanet an excesigitized datfor CLD moient with a  was accept from 2D pll. 2013 4, No 2 pp 11m the simulior and righwas digitizee was plannes measured 3 cm, tanges of lung voa for these re than 3 cmdepth fromed (Figure 1 an for tange5-126119 ation t-left d by d by . For ntial lume cases , the  skin ). ntial   For lumpacceptanthan 5 cmaccepted were anaResults a Table 1 sof patienmastectoplanning cases; 37which wunderwenline less numbers were 19 c  ectomy (intce depth of s, tangentiabut for CLlyzed to verFigure 4: Tnd discussihows a totats underwemy surgery.ranges from.5% of thesere 8% higt breast cothan 5 cm wof patient wases.  act) cases, thkin to 90% l verificatioD more thanify the real lreatment ofon l of 112 patnt breast c Measureme 2.0 to 8.0e measured her than denservative sas consideith depth mHe procedureisodose linen film was 3 cm, the ung volume breast cancients undergonservative nt of depth cm due topatients havpth of skinurgery whicred acceptaore than 5 cealth and the E was almost must be lestaken. For RE-PLAN  irradiated (F  er with Siemo breast irrasurgery (Bfrom skin t variation oe depth of s to isodoseh have intable to minimm were 18 nvironment Jou same with s than 5 cmCLD less thprocedure wigure 4). ens Mevatrdiation duriCS)/ lumpo 90% of isf the breastkin to 90%  same or lect breast, dize the volcases whileReduan et arnal, 2013, Vol mastectomy. For the casan 3 cm, thas carried  on Linac in ng this six yectomy andodose level  thickness. isodose liness than 3 epth of skinume of lun for the depl. 2013 4, No 2 pp 11 cases excepes of depth e treatmentout. All theHUSM ears study. rest underfor conventFor mastec more than cm. For pat to 90% isog irradiatedth less than 5-126120 t the more  was  data  33% went ional tomy 3 cm ients dose . The 5 cm Reduan et al. 2013 Health and the Environment Journal, 2013, Vol 4, No 2 pp 115-126 121  Table 1:  Summary data of the depth (cm) from skin surface to 90% isodose for mastectomy and lumpectomy (intact) cases  Case No. of patients Depth ( skin surface to 90% isodose) Mastectomy  75 ≤ 3cm       >3cm 33 42 Lumpectomy ( intact)  37 ≤ 5cm >5cm 19 18 Total 112 52 60  For mastectomy which distance from skin to 90% of isodose line more than 3 cm, tangential verification films were taken to measure CLD that reflected the volume of lung irradiated. For mastectomy patients, 13 cases of re-plan were identified because 56% of them have CLD more than 3 cm. Maximum CLD measured from film verification was 3.68 cm. Besides that, the maximum volume of lung included in the treatment field for BCS patient was 2.96 cm. From 25 of verification films, there were 2 re-planned cases identified (Figure 5). CLD measured by the physicist to make sure that less than 20% of lung volume involve in treatment fields. If the CLD measured more than 3 cm, some changes were done to original plan.  Reduan et al. 2013 Health and the Environment Journal, 2013, Vol 4, No 2 pp 115-126 122      According to Table 2.0, distance from skin to 90% isodose line was re-measured when the original plan has been changed. The distance for the new plan was reduced by 0.7 cm in average. The highest CLD value that has been measured was 3.68 cm which AP/PA and lateral body separation of that patient was 20 cm and 30 cm respectively. From the data, the lowest CLD value from the table was 3.05 cm for 2 patients but the AP/PA and lateral body separation of those patients were slightly same with the highest CLD patient. So that, CLD was not affected by anterior-posterior and lateral body separation.        Figure 5: The histogram of re-planned cases for mastectomy (M) and lumpectomy (L) (intact) breast Reduan et al. 2013 Health and the Environment Journal, 2013, Vol 4, No 2 pp 115-126 123  Table 2: The data of re-planned cases for mastectomy No. Depth to isodose from original plan (cm) CLD (cm) Depth to isodose after replanning (cm) Separation (cm) AP/PA Lat. 1 3.7 3.08 3.4 20.0 29.8 2 4.0 3.05 3.5 21 31.4 3 4.7 - 3.2 20 31.5 4 4.7 3.20 3.2 19.0 31.5 5 4.6 3.33 3.2 21.3 34.4 6 5.0 3.59 4.5 17.5 28 7 4.4 3.52 3.5 18 34.8 8 3.5 2.93 3.5 23.5 37.2 9 3.7 3.5 3.4 18.4 25.2 10 5.0 3.68 4.0 20 30 11 6.0 2.94 5.5 19 32 12 3.4 3.2 3.0 - - 13 4.0 3.05 3.5 20 31  There were 15 (13.4%) re-planned cases in this study since June 2006 to March 2011 (Table 3). 13 (11.61%) out of 15 were from mastectomy patients and the other 2 were from lumpectomy patients. The result shows, mastectomy patients are more often re-planned than BCS patients. The chest wall thickness is dependant in various factors. The chest wall with certain thickness plays important roles in the underlying lung depth involvement. The highest cases were recorded in the year 2008 (4 cases). There are 2 re-planned cases that involved BCS in 2007 and 2009. In 2011, there was no re-planning procedure from 8 cases. From the data, 15 out of 112 patients required re-planning due to excessive involvement of lung volume. From 15 re-planned cases, 13 of them were mastectomy patients which reflect 86.7% from overall re-planned cases. From the data, there was a significant relationship between depths of lung included in the field with number of cases re-planned for mastectomy patients. For the depth more than 3 cm, patient required a re-planning procedure. This trend cannot clearly be seen in BCS patients. The table also shows there were 63 cases of left breast cancer patients and 49 cases of right breast cancer Reduan et al. 2013 Health and the Environment Journal, 2013, Vol 4, No 2 pp 115-126 124  patient. Patients with left breast cancer are more risky to cardiac complication because of anatomy of the heart. During the treatment planning procedure, all the precautions taken to avoid any risk of cardiac complication to the patient.   Table 3: The summary of re-planned cases at HUSM from year 2006 to 2011 Year Numbers of Cases Rt. Breast Cancer Lt. Breast Cancer Numbers of Re-Planned Cases Mastectomy BCS Total 2006 12 4 8 2 0 2 2007 49 24 25 3 1 4 2008 24 11 13 4 0 4 2009 8 4 4 3 1 4 2010 11 2 9 1 0 1 2011 8 4 4 0 0 0 Total 112 49 63 13 2 15      Due to the complex geometry of the target area of breast cancer, its treatment and dose distribution is complicated and inclusion of a small portion of underlying lung area in the treatment field while treating the breast cancer is inevitable risk of late toxicities which related to volume receiving the dose higher than 20-25 Gy or more. By measuring CLD, the physicist made some changes to the original plan to spare the lung tissue from getting excessive dose. Adjustment to the lateral border has been done by shifting it up 1 cm from the previous border with permission from the oncologist. If the thickness of chest wall was very small, 0.5 cm to 1.0 cm bolus were applied to extend the depth and prevent high dose to lung tissue but the dose to the skin will be increased. For breast cancer patients who have undergone mastectomy and be treated with external beam radiotherapy, there was unavoidable presence of lung tissue in the treatment field. It was because radiotherapy treatment planning of the chest wall is complex due to missing tissue, the thin chest wall (less than 2.5 cm) and the presence of lung.As the result, there was higher dose received by the low density of lung in mastectomy breast compared to BCS. The near position of normalization point to the lung, contributed to the higher lung dose especially for the nearest point to the treatment field. Lung tissue has a lower electron density Reduan et al. 2013 Health and the Environment Journal, 2013, Vol 4, No 2 pp 115-126 125  than muscle and fat, resulting in less attenuation of the primary beam. This made the high radiosensitive of lung tissue received high dose during radiotherapy. The lateral tangential fields that enter laterally to the target volume also increased the dose by producing high internal scatter to that point.  Conclusion  From the study, we noticed several factors such as the contour of the chest wall, thickness of the chest wall; surgical procedure and general condition of the patient play a very important role. Tangential planning shows if the depth is less than 3 cm, lung volume involvement will be less. In our study, the re-planned for mastectomy cases were only 13 (11.6 %). In the other hand, only 2 out of 37 BCS patients with lung depth calculation more than 5 cm were subjected to re-planning. Overall, only 15 patients (13.4%) out of 112 patients needed a re-planning.  As a conclusion, from 112 cases, the numbers of re-planned cases for year 2006 to 2011 were only 15 (13.4%).This is less than 15%. Furthermore, our study will help more centers who do not have the facilities for simulation to verify the depth dose in 2D planning.  Acknowledgement  This study was supported financially by Incentive Grant (No. 10775) of Universiti Sains Malaysia. This work was possible with the cooperation of Radiotherapy Department, School of Medical Sciences, Hospital Universiti Sains Malaysia (HUSM) and School of Health Sciences, Universiti Sains Malaysia (USM).  References  Aspradakis, M. M., McCallum, H. M. & Wilson, N.(2006). Dosimetric and treatment planning considerations for radiotherapy of the chest wall. The British Journal of Radiology, 79, 828-836.doi:10.1259/bjr/26575438 Reduan et al. 2013 Health and the Environment Journal, 2013, Vol 4, No 2 pp 115-126 126  Candace, R.C., Indra, J.S, Harold, I.L, et al. (2009). Association between tangential beam treatment parameters and cardiac abnormalities after definitive radiation treatment for left sided breast cancer. Radiation Oncology, 72, 2,508-516. Carolyn, W.T., (2008). Breast cancer radiotherapy and heart disease. Green College, Oxford University. Fogliata, A., Nicolini, G., & Alber, et al. (2005).IMRT for breast. A Planning study. Radiotherapy and Oncology, 76,300-310 Khan, T.M., Afzal, A., Khan, A., Tahir, H., et al. (2010). A pilot study evaluating health literacy towards breast cancer among multiethnic students. Journal of Clinical and Diagnostic Research, 4, 2504-2511. Malaysian Cancer Statistics, National Cancer Council Malaysia (MAKNA),2006 Nicolini, G., Fogliata, A., & Cozzi, L.(2005). Critical appraisal of a non- coplanar technique for radiotherapy of breast minimizing lung involvement. Radiotherapy and Oncology, 76, 319-325  Redhwan. A.A., Idris, M.N., Fuad, I. et al. (2009). The differences between the quality of life of Malays and non Malays breast cancer survivor’s women from a teaching hospital, Kuala Lumpur. Journal of Community Health, 15, 98-105 Shah, A. and Sidgel, R. (2009) .A study on the area of lung tissue irradiated during treatment of breast cancer by Cobalt-60 by manual treatment planning. Post Graduate Medical Journal of National Academy of Medical Sciences, 8, 1.  World Health Organization. World Cancer Report. (2008). 2009 International Agency for Research on Cancer, Lyon.                                                                                                                                                                                                                                                   

Tangential Film Verification for Lung Volume Involvement in Breast Cancer

Radiation Treatment: East Coast Malaysia Experience

http://eprints.usm.my/35844/1/Tangential_film).pdf

Tangential Film Verification for Lung Volume Involvement in Breast Cancer Radiation Treatment: East Coast Malaysia Experience

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