A dosimetric and radiobiological evaluation of VMAT following mastectomy for patients with left-sided breast cancer

Abstract Background To compare the dosimetric, normal tissue complication probability (NTCP), secondary cancer complication probabilities (SCCP), and excess absolute risk (EAR) differences of volumetric modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) for left-sided breast cancer after mastectomy. Methods and materials Thirty patients with left-sided breast cancer treated with post-mastectomy radiation therapy (PMRT) were randomly enrolled in this study. Both IMRT and VMAT treatment plans were created for each patient. Planning target volume (PTV) doses for the chest wall and internal mammary nodes, PTV1, and PTV of the supraclavicular nodes, PTV2, of 50 Gy were prescribed in 25 fractions. The plans were evaluated based on PTV1 and PTV2 coverage, homogeneity index (HI), conformity index, conformity number (CN), dose to organs at risk, NTCP, SCCP, EAR, number of monitors units, and beam delivery time. Results VMAT resulted in more homogeneous chest wall coverage than did IMRT. The percent volume of PTV1 that received the prescribed dose of VMRT and IMRT was 95.9 ± 1.2% and 94.5 ± 1.6%, respectively (p < 0.001). The HI was 0.11 ± 0.01 for VMAT and 0.12 ± 0.02 for IMRT, respectively (p = 0.001). The VMAT plan had better conformity (CN: 0.84 ± 0.02 vs. 0.78 ± 0.04, p < 0.001) in PTV compared with IMRT. As opposed to IMRT plans, VMAT delivered a lower mean dose to the ipsilateral lung (11.5 Gy vs 12.6 Gy) and heart (5.2 Gy vs 6.0 Gy) and significantly reduced the V5, V10, V20, V30, and V40 of the ipsilateral lung and heart; only the differences in V5 of the ipsilateral lung did not reach statistical significance (p = 0.409). Although the volume of the ipsilateral lung and heart encompassed by the 2.5 Gy isodose line (V2.5) was increased by 6.7% and 7.7% (p < 0.001, p = 0.002), the NTCP was decreased by 0.8% and 0.6%, and SCCP and EAR were decreased by 1.9% and 0.1% for the ipsilateral lung. No significant differences were observed in the contralateral lung/breast V2.5, V5, V10, V20, mean dose, SCCP, and EAR. Finally, VMAT reduced the number of monitor units by 31.5% and the treatment time by 71.4%, as compared with IMRT. Conclusions Compared with IMRT, VMAT is the optimal technique for PMRT patients with left-sided breast cancer due to better target coverage, a lower dose delivered, NTCP, SCCP, and EAR to the ipsilateral lung and heart, similar doses delivered to the contralateral lung and breast, fewer monitor units and a shorter delivery time.

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A Dosimetric and Radiobiological Evaluation of VMAT Following Mastectomy for Patients With Left-sided Breast Cancer

10.21203/rs.3.rs-319267/v1 ◽

2021 ◽

Author(s):

Yun Zhang ◽

Yuling Huang ◽

Shenggou Ding ◽

Xingxing Yuan ◽

Yuxian Shu ◽

...

Keyword(s):

Breast Cancer ◽

Radiation Therapy ◽

Chest Wall ◽

Treatment Time ◽

Absolute Risk ◽

Statistical Significance ◽

Conformity Index ◽

Delivery Time ◽

Ipsilateral Lung ◽

Contralateral Lung

Abstract Background: To compare the dosimetric normal tissue complication probability (NTCP), secondary cancer complication probabilities (SCCP), and excess absolute risk (EAR) differences of volumetric modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) for left-sided breast cancer after mastectomy. Methods and materials: Thirty patients with left-sided breast cancer treated with post-mastectomy radiation therapy (PMRT) were randomly enrolled in this study. Both IMRT and VMAT treatment plans were created for each patient. Planning target volume (PTV) doses for the chest wall and internal mammary nodes, PTV1, and PTV of the supraclavicular nodes, PTV2, of 50 Gy were prescribed in 25 fractions. The plans were evaluated based on PTV1 and PTV2 coverage, homogeneity index (HI), conformity index, conformity number (CN), dose to organs at risk, NTCP, SCCP, EAR, number of monitors units, and beam delivery time. Results: VMAT resulted in more homogeneous chest wall coverage than did IMRT. The percent volume of PTV1 that received the prescribed dose of VMRT and IMRT was 95.9 ± 1.2% and 94.5 ± 1.6%, respectively (p < 0.001). The HI was 0.11 ± 0.01 for VMAT and 0.12 ± 0.02 for IMRT, respectively (p = 0.001). The VMAT plan had better conformity (CN: 0.84 ± 0.02 vs. 0.78 ± 0.04, p < 0.001) in PTV compared with IMRT. As opposed to IMRT plans, VMAT delivered a lower mean dose to the ipsilateral lung (11.5 Gy vs 12.6 Gy) and heart (5.2 Gy vs 6.0 Gy) and significantly reduced the V5, V10, V20, V30, and V40 of the ipsilateral lung and heart; only the differences in V5 of the ipsilateral lung did not reach statistical significance (p = 0.409). Although the volume of the ipsilateral lung and heart encompassed by the 2.5 Gy isodose line (V2.5) was increased by 6.7% and 7.7% (p < 0.001, p = 0.002), the NTCP was decreased by 0.8% and 0.6%, and SCCP and EAR were decreased by 1.9% and 0.1% for the ipsilateral lung. No significant differences were observed in the contralateral lung/breast V2.5, V5, V10, V20, mean dose, SCCP, and EAR. Finally, VMAT reduced the number of monitor units by 31.5% and the treatment time by 71.4%, as compared with IMRT. Conclusions: Compared with IMRT, VMAT is the optimal technique for PMRT patients with left-sided breast cancer due to better target coverage, a lower dose delivered, NTCP, SCCP, and EAR to the ipsilateral lung and heart, similar doses delivered to the contralateral lung and breast, fewer monitor units and a shorter delivery time.

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Evaluation on dosimetric plan quality and treatment delivery time of dynamic jaw mode in TomoTherapy® for left-side breast cancer patients

Journal of Radiotherapy in Practice ◽

10.1017/s1460396921000522 ◽

2021 ◽

pp. 1-8

Author(s):

Sin Ting Chiu ◽

Po Man Wu ◽

Ka Fai Cheng ◽

Pui Hei Fok ◽

George Chiu

Keyword(s):

Breast Cancer ◽

Treatment Time ◽

Organs At Risk ◽

Statistical Significance ◽

Left Lung ◽

Delivery Time ◽

Plan Quality ◽

Nodal Involvement ◽

Treatment Delivery ◽

Supraclavicular Fossa

Abstract Background: Few studies claimed that dynamic jaw (DJ) mode in Helical TomoTherapy® (HT) could improve the cranio-caudal dose distribution without prolonging the treatment time in treating different types of cancer. Also, studies suggested that DJ with a wider 5 cm field width (FW) could replace fixed jaws (FJ) with 2.5 cm FW to reduce the delivery time with the sustainable plan quality. Yet, the study on breast cancer with supraclavicular fossa (SCF) nodal involvement using DJ mode in HT is limited. This study aims to evaluate the DJ mode retrospectively by comparing their dosimetric quality with normal tissue complication probability (NTCP) of organs at risk and treatment delivery time with FJ mode on treating left-side breast with SCF nodal involvement. Materials and methods: All post-mastectomy patients, who had been irradiated for left-side breast with SCF nodal involvement were selected retrospectively in this study. With the same dose constraint and prescription as the treated DJ2.5 plan, two extra plans using DJ mode with 5 cm FW(DJ5.0) and FJ mode with 2.5 cm FW (FJ2.5) were computed for plan comparison. Results: No statistical significance was found in all the parameters of PTV and OARs, except for V20 of whole lung. DJ5.0 received V20 in ipsilateral left lung than FJ2.5 and DJ2.5. However, the average delivery time of DJ5.0 was significantly lower than that of DJ2.5 and FJ2.5 by almost 40%. Conclusions: No statistical significance was found in those dosimetric and radiobiological parameters among three modes while the delivery time has greatly reduced by using DJ5.0. A shorter treatment time can minimise intra-fractional error and better the patient’s experience during treatment.

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Dosimetric Comparison of IMRT, Hybrid IMRT and Hybrid VMAT For Early Stage Right-Sided Breast Cancer

10.21203/rs.3.rs-665208/v1 ◽

2021 ◽

Author(s):

Suyan Bi ◽

Rui Zhu ◽

Zhitao Dai

Keyword(s):

Breast Cancer ◽

Early Stage ◽

Absolute Risk ◽

Organs At Risk ◽

Volumetric Modulated Arc Therapy ◽

Intensity Modulated Radiotherapy ◽

Contralateral Breast ◽

Early Stage Breast Cancer ◽

Ipsilateral Lung ◽

Contralateral Lung

Abstract Purpose This study aimed to evaluate the clinical impact of hybrid intensity-modulated radiotherapy (IMRT) and hybrid volumetric-modulated arc therapy (VMAT) for early-stage breast cancer, including plan quality and second cancer risk (SCR). Methods Three different plans were designed in full IMRT, hybrid IMRT, and hybrid VMAT for each of eight patients with early-stage breast cancer. Target quality, organs at risk (OARs) sparing, and SCR were compared among the three plans. Results Compared with the hybrid IMRT, full IMRT showed deterioration in terms of D2% of simultaneous integrated boost (SIB), V10 of ipsilateral lung, and excess absolute risk (EAR) to contralateral lung and esophagus. The homogeneity index (HI) of SIB, V5 of ipsilateral lung and combined lung, the Dmax and Dmean of the esophagus, the EAR to contralateral breast and lung, and the EAR to the esophagus with hybrid VMAT dramatically increased by 12.5%, 19.49%, 18.87%, 90.59%, 167.69%, 50.14%, 264.68%, and 160.95%, respectively (p = 0.022; 0.040; 0.044; 0.041; 0.003; 0.020; 0.000; 0.003). The EAR to contralateral breast and contralateral lung by full IMRT was significantly decreased compared with the hybrid VMAT (26.97%, p = 0.033; 50.01%, p = 0.026). Conclusion The results confirmed that hybrid IMRT could achieve better target quality and OARs sparing than full IMRT and hybrid VMAT for early-stage right breast cancer. Hybrid IMRT was the best treatment option, while hybrid VMAT performed the worst among the three plans in terms of SCR to peripheral OARs.

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Outcome of treatment for breast cancer patients with chest wall recurrence according to initial stage: Implications for post-mastectomy radiation therapy

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/s0360-3016(03)00431-0 ◽

2003 ◽

Vol 57 (1) ◽

pp. 128-135 ◽

Cited By ~ 18

Author(s):

Anees Chagpar ◽

Henry M Kuerer ◽

Kelly K Hunt ◽

Eric A Strom ◽

Thomas A Buchholz

Keyword(s):

Breast Cancer ◽

Radiation Therapy ◽

Cancer Patients ◽

Chest Wall ◽

Breast Cancer Patients ◽

Chest Wall Recurrence ◽

Initial Stage

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Chest Wall Recurrence Rates for Low Risk Patients With Close/Positive Margins After Mastectomy for Breast Cancer, Treated With Reexcision and No Postmastectomy Radiation Therapy (PMRT)

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2015.07.667 ◽

2015 ◽

Vol 93 (3) ◽

pp. E49 ◽

Cited By ~ 1

Author(s):

J.S. Chang ◽

F. Wang ◽

C. Ewing ◽

M.D. Alvarado ◽

L. Esserman ◽

...

Keyword(s):

Breast Cancer ◽

Radiation Therapy ◽

Chest Wall ◽

Low Risk ◽

Recurrence Rates ◽

Positive Margins ◽

Chest Wall Recurrence ◽

Postmastectomy Radiation ◽

Risk Patients ◽

Postmastectomy Radiation Therapy

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Dosimetric Comparison of Three Radiotherapy Techniques in Irradiation of Left-Sided Breast Cancer Patients after Radical Mastectomy

BioMed Research International ◽

10.1155/2020/7131590 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Jian Hu ◽

Guang Han ◽

Yu Lei ◽

Ximing Xu ◽

Wei Ge ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Volumetric Modulated Arc Therapy ◽

Intensity Modulated Radiation Therapy ◽

Radical Mastectomy ◽

Target Volume ◽

Conformity Index ◽

Breast Cancer Patients ◽

Ipsilateral Lung ◽

Significant Difference

Introduction. This study is aimed at evaluating the dosimetric differences among target segmented planning (TSP), conventional 9-field intensity modulated radiation therapy (9FIMRT) planning, and volumetric modulated arc therapy (VMAT) planning for postmastectomy radiotherapy of left-sided breast cancer patients. Material and Methods. Fifteen left-sided breast cancer patients who underwent radical mastectomy were enrolled. In TSP, the planning target volume (PTV) was divided into four regions (supra/infraclavicular, chest wall, external mammary region, and internal mammary region), and each individual PTV region was treated with respective fixed fields. Results. The VMAT plans showed superior to PTV dose conformity index (CI), homogeneity index (HI), protection of the ipsilateral lung, monitor units (MUs), and maximum dose (Dmax) to the contralateral breast compared with TSP and 9FIMRT plans. The TSP provided better protection for Dmean of the heart and left ventricle (p<0.05). A dose for left anterior descending artery from the three techniques had no significant difference. Compared with the 9FIMRT plans, the V5Gy (%) and V10Gy (%) for the ipsilateral lung were significantly reduced with TSP and VMAT (p<0.05). The V5Gy (%) and V10Gy (%) for the ipsilateral lung turned out to be similar between VMAT and TSP techniques. Conclusions. Our study indicates that VMAT should be a better choice of radiotherapy for left-sided breast cancer patients after radical mastectomy. If VMAT is unavailable, 9FIMRT can achieve better CI and HI values and be more MU-efficient compared with TSP; however, TSP can effectively reduce the low dose volume of the ipsilateral lungs and heart.

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5 years of experience with DIBH (Deep inspiration breath-hold) combined with SGRT (Surface-Guided Radiation Therapy) in left-sided breast cancer

Senologie - Zeitschrift für Mammadiagnostik und -therapie ◽

10.1055/a-0849-0524 ◽

2020 ◽

Vol 17 (01) ◽

pp. 14-23

Author(s):

Claudia Steffal ◽

Annemarie U. Schratter-Sehn ◽

Karin Brinda-Raitmayr ◽

Thomas Kann ◽

Daniela Mailat ◽

...

Keyword(s):

Breast Cancer ◽

Radiation Therapy ◽

Side Effects ◽

Left Lung ◽

Breath Hold ◽

Relative Reduction ◽

Deep Inspiration ◽

Deep Inspiration Breath Hold ◽

Ipsilateral Lung

Abstract Background Radiation treatment to the left breast is associated with increased cardiac morbidity as well as mortality. Deep inspiration breath-hold (DIBH) technique with Surface Guided Radiation Therapy (SGRT) could have dosimetric advantages over the free breathing technique (NB, normal breathing) in cardiac (heart and LAD) and ipsilateral lung sparing in patients with left-sided breast cancer after surgery. Therefore this technique was implemented in 2013 at the institute of radiooncology at the KFJ/SMZ-South – Hospital Vienna. Methods From Oct 2013 – December 2018 548 patients were referred to radiotherapy following conservative operation of left-sided invasive breast cancer. All patients gave their informed consent and underwent training sessions for the DIBH-technique independent of age or breathing activity or respiratory disorders. Patients who turned out to be unfit for DIBH were enrolled for NB. The relative reduction in Dmean heart and left lung dose was compared between the two cohorts. Acute radiation induced side effects were classified according to the Radiation Therapy Oncology Group/The European Organisation for Research (RTOG) 37; late toxicity rates according to the Common Terminology Criteria for Adverse Events (CTCAE Version 4.03) Results The median age of the DIBH-patients was 58 years (27–90), of the NB-patients 65 (30–80) years. Follow-up was obtained until June 2019. The median follow-up was 52 months (range 7–73 m). The average coverage of Dmean left lung was 6.91 Gy (1.44 Gy – 12.4 Gy). The average coverage of Dmean heart was 1.17 Gy (0.12 Gy – 3.19 Gy) in the DIBH-cohort. The NB – plans had a Dmean of 8.92 Gy (5.23–16.9 Gy) at the ipsilateral lung and a Dmean of 2.31 Gy (0.71–4.21 Gy) at the heart. This shows that the DIBH-technique halved the Dmean of the heart. The amount of acute side effects was comparable between the two groups: RTOG 1: 70.8 % vs. 64 %, RTOG 3 6.6 % vs. 5.6 %, no reaction 3.2 % vs. 1.4 %. There were more CTCAE 1-late events in the NB-group (51.6 % vs. 12.67 %). Conclusion Deep inspiration breath-hold (DIBH) technique with Surface Guided Radiation Therapy (SGRT) is a rather simple, reproducable method with a high acceptance of the patients who can actively participate in the whole treatment process. The mean dose at the heart and the left lung can be reduced, at the heart even by as much as 50 %.

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