Radiation dose distribution in functional heart regions from tangential breast cancer radiotherapy

详细信息    查看全文

• 作者：Daniel Wollschlä ; ger^a ; ^{wollschlaeger@uni-mainz.de" class="auth_mail" title="E-mail the corresponding author} ; Heiko Karle^b ; Marcus Stockinger^b ; Detlef Bartkowiak^c ; Sandra Bü ; hrdel^c ; Hiltrud Merzenich^a ; Thomas Wiegel^c ; Maria Blettner^a ; Heinz Schmidberger^b
• 关键词：Breast cancer ; Heart dose ; Dosimetry ; Dose&ndash ; volume histogram
• 刊名：Radiotherapy and Oncology
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：119
• 期：1
• 页码：65-70
• 全文大小：586 K

文摘

To analyze the distribution of individually-determined radiation dose to the heart and its functional sub-structures after radiotherapy in breast cancer patients treated in Germany during 1998–2008.

Material and methods

We obtained electronic treatment planning records for 769 female breast cancer patients treated with megavoltage tangential field radiotherapy. All dose distributions were re-calculated using Eclipse with the anisotropic analytical algorithm (AAA) for photon fields, and the electron Monte Carlo algorithm for electron boost fields. Based on individual dose volume histograms for the complete heart and several functional sub-structures, we estimated various dose measures in patient groups.

Results

Mean heart dose spanned a range of 0.9–19.1 Gy for left-sided radiotherapy and 0.3–11.6 Gy for right-sided radiotherapy. Average (median) mean heart dose was 4.6 Gy (3.7 Gy) for left-sided radiotherapy, and 1.7 Gy (1.4 Gy) for right-sided RT. With left-sided radiotherapy, 66% of the patients had 2 cm³ of the complete heart exposed to at least 40 Gy. Younger age, higher body mass index, tumor location in a medial quadrant, and presence of a parasternal field were also associated with higher heart dose.

Conclusion

Tumor location and treatment choices influence cardiac dose with complex interactions. There is considerable variability in heart dose, with dose metrics of different cardiac sub-structures showing different patterns in their dependency on external influences. Dose–response analysis of late cardiac effects after radiotherapy requires detailed individual dosimetry.