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Ueda Y, Gerber NK, Das IJ. Model-based cardiac dose estimation in radiation treatment of left breast cancer. Br J Radiol 2018; 91:20180287. [PMID: 30044144 DOI: 10.1259/bjr.20180287] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE: To develop a mathematical model for cardiac dose estimation for patients who have been treated for left-sided breast cancer without CT data. METHODS: After obtaining institutional review board approvals, 147 patients with left-sided breast cancer were selected that were treated supine with opposed tangents. The heart blocks from the tangential fields were removed and dose calculations were performed with 6 MV beams using an advanced algorithm. This study was performed with CT data with DRR to represent a radiographic simulator image of yesteryear treatments. The beam's eye-view images showing delineated breast, lung and heart were created to represent views on radiograph. The maximum heart distance (MHD) was recorded and irradiated heart area (AREA) was computed by combination of triangles and rectangles. Based on accurate 3D dose calculation, mean dose (Dmean) and V10 to V50 of heart were analyzed with respect to MHD and AREA for dosimetric parameters using linear and quadratic fit. RESULTS: The treatment parameters calculated by MHD and segments using 2D radiographs were within 2% of the actual dosimetric parameters computed from the 3D planning system. The MHD and AREA vs Dmean, V10, V20, V30 and V50 showed very good correlation with linear model (R2 > 0.91); however the correlation was significantly better with quadratic model (R2 > 0.92). The analysis of the dosimetric error with our linear and quadratic model is remarkable within <3% error for most cases. CONCLUSION: The proposed mathematical model for the cardiac dose estimation is accurate within ±3% using a radiograph without CT data. This provides avenues for patient pooling in future studies related to radiation dose and cardiac toxicity. These results will help in estimating cardiac dose analysis accurately from previous studies as well as in centers still using 2D planning. ADVANCES IN KNOWLEDGE: The evidence of cardiac risk following radiotherapy continues to be one of the important considerations for the management of left-sided breast cancer patients. One of the problem in the estimation of dose-risk effects is the reconstruction of heart dose for pre-CT treatments. In this study, a simple mathematical model is presented that could estimate cardiac dose within ±3% in left breast cancer treatment from 2D radiograph where CT data do not exist.
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Affiliation(s)
- Yoshihiro Ueda
- 1 Department of Radiation Oncology, Osaka International Cancer Institute , Osaka , Japan
| | - Naamit K Gerber
- 2 Department of Radiation Oncology, New York University Health & Laura and Isaac Perlmutter Cancer Center , New York, NY , USA
| | - Indra J Das
- 2 Department of Radiation Oncology, New York University Health & Laura and Isaac Perlmutter Cancer Center , New York, NY , USA
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2
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Dosimetric comparison of field in field intensity-modulated radiotherapy technique with conformal radiotherapy techniques in breast cancer. Jpn J Radiol 2010; 28:283-9. [DOI: 10.1007/s11604-010-0423-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 01/21/2010] [Indexed: 11/26/2022]
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3
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Calculation and Prediction of the Effect of Respiratory Motion on Whole Breast Radiation Therapy Dose Distributions. Med Dosim 2009; 34:126-32. [DOI: 10.1016/j.meddos.2008.07.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2008] [Revised: 06/30/2008] [Accepted: 07/19/2008] [Indexed: 11/17/2022]
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4
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Dosimetric Effects of Setup Uncertainties on Breast Treatment Delivery. Med Dosim 2008; 33:293-8. [DOI: 10.1016/j.meddos.2008.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 01/20/2008] [Indexed: 11/20/2022]
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Prabhakar R, Rath GK, Julka PK, Ganesh T, Joshi RC, Manoharan N. Breast dose heterogeneity in CT-based radiotherapy treatment planning. J Med Phys 2008; 33:43-8. [PMID: 19893689 PMCID: PMC2772029 DOI: 10.4103/0971-6203.41191] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 02/11/2008] [Indexed: 11/24/2022] Open
Abstract
The aim of this study was to evaluate the breast dose heterogeneity in CT-based radiotherapy treatment planning and to correlate with breast parameters. Also, the number of slices required for treatment planning in breast cancer by tangential field technique has been assessed by comparing the treatment plans according to International Commission on Radiation Units and Measurement (ICRU) 50 guidelines (1993) for single-slice, three-slice, and multi-slice (3D) planning . Sixty women who underwent isocentric tangential field breast radiotherapy were included in this study. The plans were optimized and analyzed with dose volume histograms. Sixty-three percent of the single-slice plans and 26.7% of the three-slice plans showed poor dose homogeneity as compared to the 3D plans. Dose inhomogeneity correlated better with breast volume (r2 = 0.43) than the chest wall separation (r2 = 0.37) and breast area product (r2 = 0.36). Similarly, breast volume correlated better with breast area product (r2 = 0.80) than with chest wall separation (r2 = 0.56). Breast volume can be approximated to breast area product from the relation, breast volume = [(breast area product × 8.85) − 120.05]. The results of this study showed that most of the cases require 3D planning for breast cancer. It also showed that patients with large breast are prone to have more dose inhomogeneity with standard tangential field radiotherapy. In centers where 3D planning is not possible due to lack of facilities or workload, three slices–based planning can be performed to approximate the dosimetric advantage of 3D planning.
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Affiliation(s)
- R Prabhakar
- Department of Radiotherapy, Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, New Delhi, India
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Dundas KL, Atyeo J, Cox J. What is a large breast? Measuring and categorizing breast size for tangential breast radiation therapy. ACTA ACUST UNITED AC 2007; 51:589-93. [DOI: 10.1111/j.1440-1673.2007.01898.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Koseoglu FG, Tuncel N, Kizildag AU, Garipagaoglu M, Adli M, Andic C. Assessment of setup accuracy in patients receiving postmastectomy radiotherapy using electronic portal imaging. ACTA ACUST UNITED AC 2007; 25:45-52. [PMID: 17541512 DOI: 10.1007/s11604-006-0102-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Accepted: 10/25/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE The aim of this study was to investigate the setup accuracy for patients undergoing postmastectomy radiotherapy using electronic portal imaging. MATERIALS AND METHODS Ten patients undergoing radiotherapy via tangent (TG), supraclavicular-axillary (SA), and internal mammary (IM) fields were included. To explore the setup accuracy, distances between chosen landmarks were taken as reference parameters (RPs). The difference between measured RPs on simulation films and electronic portal images (EPIs) was calculated as the setup error. RESULTS A total of 30 simulation films and 120 EPIs were evaluated. In the SA field, calculated RPs were lung length (LL), clavicle-field center perpendicular distance, and clavicle-field center transverse distance. The mean of the standard deviations (SDs) of the random errors (sigma) for these parameters were 4.7, 7.3, and 7.6; and the SDs of the systematic errors (Sigma) were 6.8, 4.4, and 13.5, respectively. In the TG fields, the calculated RPs were the central lung distance (CLD), maximum lung distance (MLD), and central soft-tissue distance (CSTD). In the medial TG field, the sigma values for these parameters were 3.4, 3.6, and 4.1, respectively; and the sigma values were 6.6, 2.6, and 3.4, respectively. In the lateral TG field, Sigma values for the calculated RPs were 2.4, 3.2, and 3.3l, respectively; and the Sigma values were 5.6, 3.6, and 4.8, respectively. CONCLUSION CLD, MLD, and CSTD in TG fields and LL in SA fields are easily identifiable and are helpful for detecting setup errors using EPIs in patients undergoing postmastectomy radiotherapy.
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Affiliation(s)
- Funda Gul Koseoglu
- Department of Radiation Oncology, Akdeniz University School of Medicine, Antalya, Turkey
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Donovan E, Bleakley N, Denholm E, Evans P, Gothard L, Hanson J, Peckitt C, Reise S, Ross G, Sharp G, Symonds-Tayler R, Tait D, Yarnold J. Randomised trial of standard 2D radiotherapy (RT) versus intensity modulated radiotherapy (IMRT) in patients prescribed breast radiotherapy. Radiother Oncol 2007; 82:254-64. [PMID: 17224195 DOI: 10.1016/j.radonc.2006.12.008] [Citation(s) in RCA: 331] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 12/08/2006] [Accepted: 12/12/2006] [Indexed: 12/20/2022]
Abstract
BACKGROUND Radiation dose distributions created by two dimensional (2D) treatment planning are responsible for partial volumes receiving >107% of the prescribed dose in a proportion of patients prescribed whole breast radiotherapy after tumour excision of early breast cancer. These may contribute to clinically significant late radiation adverse effects. AIM To test three dimensional (3D) intensity modulated radiotherapy (IMRT) against 2D dosimetry using standard wedge compensators in terms of late adverse effects after whole breast radiotherapy. METHODS Three hundred and six women prescribed whole breast radiotherapy after tumour excision for early stage cancer were randomised to 3D IMRT (test arm) or 2D radiotherapy delivered using standard wedge compensators (control arm). All patients were treated with 6 or 10MV photons to a dose of 50Gy in 25 fractions to 100% in 5 weeks followed by an electron boost to the tumour bed of 11.1Gy in 5 fractions to 100%. The primary endpoint was change in breast appearance scored from serial photographs taken before radiotherapy and at 1, 2 and 5 years follow up. Secondary endpoints included patient self-assessments of breast discomfort, breast hardness, quality of life and physician assessments of breast induration. Analysis was by intention to treat. RESULTS 240 (79%) patients with 5-year photographs were available for analysis. Change in breast appearance was identified in 71/122 (58%) allocated standard 2D treatment compared to only 47/118 (40%) patients allocated 3D IMRT. The control arm patients were 1.7 times more likely to have a change in breast appearance than the IMRT arm patients after adjustment for year of photographic assessment (95% confidence interval 1.2-2.5, p=0.008). Significantly fewer patients in the 3D IMRT group developed palpable induration assessed clinically in the centre of the breast, pectoral fold, infra-mammary fold and at the boost site. No significant differences between treatment groups were found in patient reported breast discomfort, breast hardness or quality of life. CONCLUSION This analysis suggests that minimisation of unwanted radiation dose inhomogeneity in the breast reduces late adverse effects. Incidence of change in breast appearance was statistically significantly higher in patients in the standard 2D treatment arm compared with the IMRT arm. A beneficial effect on quality of life remains to be demonstrated.
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Affiliation(s)
- Ellen Donovan
- Joint Department of Physics, Royal Marsden Hospital and Institute of Cancer Research, Sutton, Surrey, UK
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Das IJ, Shikama N, Cheng CW, Solin LJ. Choice of beam energy and dosimetric implications for radiation treatment in a subpopulation of women with large breasts in the United States and Japan. Med Dosim 2006; 31:216-23. [PMID: 16905453 DOI: 10.1016/j.meddos.2006.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Revised: 01/27/2006] [Accepted: 02/02/2006] [Indexed: 11/28/2022]
Abstract
Radiation complications are often related to the dose inhomogeneity (hot spot) in breast tissue treated with conservative therapy, especially for large patients. The effect of photon energy on radiation dose distribution is analyzed to provide guidelines for the selection of beam energy when tangential fields and limited slices are used to treat women with large breasts. Forty-eight patients with chest wall separation > 22 cm were selected for dosimetric analysis. We compared the maximum dose in the central axis (CAX) plane (2D) using 6-, 10-, and 18-MV photon beams in all patients and 3D data set for 16 patients. Correlation between hot spot dose (HSD), separation, breast cup size, breast volume, and body weight was derived with beam energy. Among the 48 patients in this study, HSD > 10% in the CAX plane was noted in 98%, 46%, and 4% of the population when 2D dosimetry was performed; however, with 3D study, it was in 50%, 19%, and 6% of the patients with 6-MV, 10-MV and 18-MV beams, respectively. The chest wall separation, body weight, and breast volume were correlated with the HSD in both the 2D and 3D plans. Patient's bra size was not correlated with the hot spot. The chest wall separation was found to be the most important parameter to correlate with hot spot in tangential breast treatment. Simple guidelines are provided for dose uniformity in breast with respect to chest wall separation, body weight, bra size, and breast volume with tangential field irradiations.
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Affiliation(s)
- Indra J Das
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Bauduceau O, Pons P, Campana F, Bollet M, Romero L, Fayolle M. Comparaison simulation classique–simulation virtuelle au cours d'une irradiation mammaire : étude prospective sur 14 patientes. Cancer Radiother 2005; 9:402-10. [PMID: 16226470 DOI: 10.1016/j.canrad.2005.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE To compare conventional 2D simulation and virtual simulation on 14 patients with breast cancer. PATIENTS AND METHODS Patients were simulated for treatment using standard procedure. They subsequently underwent CT scan in the treatment position. The CTV was defined as breast tissue. The PTV was obtained by adding a 3D margin of 1 cm around CTV. Organs at risk (lungs and heart) were outlined. Ballistics and dose distribution obtained with the two planning methods were compared. RESULTS With conventional simulation, 95% of CTV received 95% of the dose prescribed. Virtual simulation significantly improved dosimetric coverage of PTV without increasing irradiation volume of lung and heart. In 2D simulation, using three slices allowed optimisation by adjusting wedge angle. The five-slice plan was a much better predictor of the maximum dose regions when compared to the three-slice plan. Using entire CT data didn't give any benefit. CONCLUSION Variations in CTV delineation and PTV definition limit interest of virtual simulation. In classic simulation, a 5 CT slice-plan can be used to optimise dose distribution.
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Affiliation(s)
- O Bauduceau
- Service d'oncologie-radiothérapie, HIA du Val-de-Grâce, 74, boulevard du Port-Royal, 75005 Paris, France.
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Trouncer RJ, Rowbottom CG, Budgell GJ, Mackay RI, Magee B. Intensity-modulated Radiotherapy Planning from Limited Anatomical Information: Is Sim-CT Sufficient for Planning Women with Breast Cancer Receiving Intensity-modulated Radiotherapy? Clin Oncol (R Coll Radiol) 2005; 17:343-51. [PMID: 16097565 DOI: 10.1016/j.clon.2005.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS To investigate intensity-modulated radiotherapy (IMRT) plans for women with carcinoma of the breast, using a small number of Sim-CT slices, thus avoiding changing the patient's position and potential problems with CT capacity. MATERIALS AND METHODS Ten CT scans of women with breast cancer were obtained for use in the study. IMRT plans based on an open tangent pair and additional top-up segment fields were created using the full CT scan, and represented the gold standard treatment plan for comparison purposes. Five-slice CT simulator scans were artificially created by omitting intermediate slices from the full CT scans. Additionally, the intermediate CT slices were recreated via interpolation of the five slices using a standard interpolation algorithm. IMRT plans were created in the same way as for the full CT scans. To allow a suitable plan comparison to be made, the beam segments and monitor units were transferred to the full CT scans, and the dose distribution calculated. RESULTS The interpolated five-slice plans showed no significant difference in the volume of tissue receiving dose outside the range 95-105%, compared with the IMRT plans created using the full CT data set (1.3 +/- 2.2%, P = 0.092). In contrast, the discrete slice CT simulator plans increased by 6.3 +/- 5.4%, P = 0.0054, showing a statistically significant difference in the dose distribution produced and a clinically inferior plan. CONCLUSIONS Plans created using five discrete slice CT scans were inferior to full CT-derived IMRT treatment plans, and are therefore not acceptable for IMRT. However, interpolating five CT simulator slices provides adequate anatomical information to produce comparable IMRT plans to those created by full CT scans of the patient. This allows the introduction of IMRT for this patient group without the need to change treatment position to accommodate CT scanning.
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Affiliation(s)
- R J Trouncer
- Christie Hospital NHS Trust, Withington, Manchester M20 4BX, UK.
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Winfield EA, Deighton A, Venables K, Hoskin PJ, Aird EGA. Survey of tangential field planning and dose distribution in the UK: background to the introduction of the quality assurance programme for the START trial in early breast cancer. Br J Radiol 2003; 76:254-9. [PMID: 12711645 DOI: 10.1259/bjr/59091776] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
A background survey of UK breast radiotherapy techniques was performed prior to the introduction of the quality assurance programme for the Standardization of Radiotherapy (START) trial in breast cancer, a UK multicentre randomized trial of different dose fractionations for breast radiotherapy. Analysis of patient treatment plans was performed at this initial stage of the quality assurance programme to ensure eventual uniformity of treatment within the randomized trial and hence ensure reliable end results. As an integral part of this initial survey, three patient outlines of different size and shape were circulated between November 1997 and January 1998 to 56 UK radiotherapy centres. Dose distributions were produced according to the routine planning protocol of each department to provide information on treatment planning techniques. Criteria used for treatment plan production and the resultant dose distributions were analysed. The dose distributions varied between centres. Dose inhomogeneity of no more than 10% was achieved, on the central axis, for all chest wall and medium breast size plans. The number of larger breast size distributions exceeding a 10% dose gradient across the treatment volume was 54% (26). Most centres in the UK determine the breast dose distribution by planning on a two-dimensional contour taken along the central plane of the breast. Variation in the breast contour either side of this central plane is not taken into account. Care with plan optimization by selecting the most appropriate beam parameters can lead to an improvement in breast dosimetry.
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Affiliation(s)
- E A Winfield
- Marie Curie Research Wing, Mount Vernon Hospital, Rickmansworth Road, Northwood, Middlesex HA6 2RN, UK
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Vicini FA, Sharpe M, Kestin L, Martinez A, Mitchell CK, Wallace MF, Matter R, Wong J. Optimizing breast cancer treatment efficacy with intensity-modulated radiotherapy. Int J Radiat Oncol Biol Phys 2002; 54:1336-44. [PMID: 12459355 DOI: 10.1016/s0360-3016(02)03746-x] [Citation(s) in RCA: 214] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
PURPOSE To present our clinical experience using intensity-modulated radiation therapy (IMRT) to improve dose uniformity and treatment efficacy in patients with early-stage breast cancer treated with breast-conserving therapy. METHODS AND MATERIALS A total of 281 patients with Stage 0, I, and II breast cancer treated with breast-conserving therapy received whole breast RT after lumpectomy using our static, multileaf collimator (sMLC) IMRT technique. The technical and practical aspects of implementing this technique on a large scale in the clinic were analyzed. The clinical outcome of patients treated with this technique was also reviewed. RESULTS The median time required for three-dimensional alignment of the tangential fields and dosimetric IMRT planning was 40 and 45 min, respectively. The median number of sMLC segments required per patient to meet the predefined dose-volume constraints was 6 (range 3-12). The median percentage of the treatment given with open fields (no sMLC segments) was 83% (range 38-96%), and the median treatment time was <10 min. The median volume of breast receiving 105% of the prescribed dose was 11% (range 0-67.6%). The median breast volume receiving 110% of the prescribed dose was 0% (range 0-39%), and the median breast volume receiving 115% of the prescribed dose was also 0%. A total of 157 patients (56%) experienced Radiation Therapy Oncology Group Grade 0 or I acute skin toxicity; 102 patients (43%) developed Grade II acute skin toxicity and only 3 (1%) experienced Grade III toxicity. The cosmetic results at 12 months (95 patients analyzable) were rated as excellent/good in 94 patients (99%). No skin telengiectasias, significant fibrosis, or persistent breast pain was noted. CONCLUSION The use of intensity modulation with our sMLC technique for tangential whole breast RT is an efficient method for achieving a uniform and standardized dose throughout the whole breast. Strict dose-volume constraints can be readily achieved resulting in both uniform coverage of breast tissue and a potential reduction in acute and chronic toxicities. Because the median number of sMLC segments required per patient is only 6, the treatment time is equivalent to conventional wedged-tangent treatment techniques. As a result, widespread implementation of this technology can be achieved with minimal imposition on clinic resources and time constraints.
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Affiliation(s)
- Frank A Vicini
- Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI 48073, USA.
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Muren LP, Maurstad G, Hafslund R, Anker G, Dahl O. Cardiac and pulmonary doses and complication probabilities in standard and conformal tangential irradiation in conservative management of breast cancer. Radiother Oncol 2002; 62:173-83. [PMID: 11937244 DOI: 10.1016/s0167-8140(01)00468-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND PURPOSE The clinical benefit of irradiating the intact breast after lumpectomy must be weighted against the risk of severe toxicity. We present a study on cardiac and pulmonary dose-volume data and the related complication probabilities of tangential breast irradiation having the following objectives: (1) to quantify the sparing of the organs at risk (ORs), the heart and the lung, achieved by three-dimensional (3-D) conformal tangential irradiation (CTI) as compared to standard tangential irradiation (STI); (2) to elucidate the uncertainty in radiation tolerance data; and (3) to analyse the relation between the amount of OR irradiated and the resulting morbidity risk. MATERIAL AND METHODS Computed tomography (CT)-based 3-D treatment plans of 26 patients prescribed to CTI of the intact breast were applied. Contour-based STI has been our routine treatment, and was reconstructed for all patients. Dose-volume data and normal tissue complication probability (NTCP) predictions from the probit and relative seriality models with several cardiac and pulmonary tolerance parameterizations were analysed and compared. RESULTS AND CONCLUSIONS A significant amount of normal tissues can be spared from radiation by using CT-based CTI, resulting in a 50% reduction of the average excess cardiac mortality risk in the left-sided cases. The risks for pericarditis and pneumonitis were too low to reveal any clinically significant difference between the treatments. For the STI set-up, a regression analysis showed that the excess cardiac mortality risk increased when larger parts of the heart were inside the fields. However, the different excess cardiac mortality and pneumonitis tolerance parameters resulted in statistically significant different NTCPs, which precluded the ability to accurately predict absolute NTCPs after tangential breast irradiation. Despite this uncertainty the different series of cardiac and pulmonary risk predictions were in relatively good agreement when small volumes of the ORs were irradiated. From the present data and without consideration of patient or organ motion, it therefore appears that tangential breast irradiation with less than 1 cm of the heart and 2-2.5 cm of the lung included inside the treatment fields will cause at most 1 per thousand risk for cardiac mortality and pulmonary morbidity. CT-based CTI should be considered, in particular for the left-sided cases, if these requirements cannot be met.
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Affiliation(s)
- Ludvig Paul Muren
- Department of Radiophysics, Haukeland University Hospital, N-5021 Bergen, Norway
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Vicini FA, Sharpe M, Kestin L, Martinez A, Wong J. Intensity-Modulated Radiation Therapy for Breast Cancer. ACTA ACUST UNITED AC 2002. [DOI: 10.2165/00024669-200201040-00001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Delaney G, Blakey D, Drummond R, Kenny L, Centre RO. Breast radiotherapy: an Australasian survey of current treatment techniques. AUSTRALASIAN RADIOLOGY 2001; 45:170-8. [PMID: 11380359 DOI: 10.1046/j.1440-1673.2001.00898.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Prior to the dissemination of evidence-based quality assurance guidelines, the Australian National Breast Cancer Centre Radiation Oncology Group conducted a process survey of breast radiotherapy treatment delivery throughout Australia. A process survey was conducted in August/September 1998. This survey comprised questions enquiring about treatment positioning, immobilization devices used, planning strategies, simulation and dose computation methods, treatment prescribing and quality assurance. The survey was sent to 123 Australian fellows of the Royal Australian and New Zealand College of Radiologists (RANZCR) and to the six directors of New Zealand radiation oncology departments. Fifty-eight questionnaires were returned of which 38 were received from individuals and 20 represented a reply from a department with a routine breast radiotherapy protocol (representing an average of 4.5 radiation oncologists per reply). The study identified great consistency between departments with respect to dose and fractionation for breast tangents. The study also identified some areas of treatment planning and delivery that varied between individuals or departments. These mainly reflected a lack of evidence in some areas of radiotherapy treatment delivery. The circulation of quality assurance guidelines will perhaps improve consistency of radiotherapy techniques in which studies have identified that technique changes improve outcome. This study identified that these areas include the taking of simulation and port films and the use of off-axis dosimetry. Further studies are required for areas of radiotherapy treatment delivery that have little evidence for or against their implementation.
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Affiliation(s)
- G Delaney
- Liverpool Hospital Cancer Therapy Centre, Liverpool, New South Wales, Australia.
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