Preventing Cardiotoxicity in Personalized Breast Irradiation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Edy Ippolito and colleagues described “Preventing Cardiotoxicity in Personalized Breast Irradiation”. In the present study, the data was extracted and analyzed from 197 patients including 394 treatment plans in combination of anatomical factors. The authors described the benefit of a deep inspiration breath hold over standard irradiation technique which has higher incidence of adverse cardiac effects, especially in left-sided breast cancer mainly for left descending artery irradiation. Authors claim that deep inspiration breath hold dosimetric is advantageous and this technique reduces the left descending artery irradiation significantly and should be always preferred.

Overall, as authors mentioned in discussion section, that “topic is not novel this is the first study that built a model based on several FB anatomical data. The findings are useful and important for the clinical community, especially because the larger number of cancer patients where cardiotoxicity has been always a big concern in patients after radiotherapy. The manuscript is scientifically sound and written well.  

Manuscript can be accepted after following minor comment:

“Institutional Review Board Statement”  and  “Informed Consent Statement “ should be moved in Methods and Material section, before Patient selection

Author Response

We would like to thank the reviewer for the time spent reviewing our manuscript. We modified the manuscript according to the reviewer’s comments. All changes are tracked in the manuscript and additional section have been highlighted. We also provided a point by point response to the reviewers’comments.

Reviewer 1

Edy Ippolito and colleagues described “Preventing Cardiotoxicity in Personalized Breast Irradiation”. In the present study, the data was extracted and analyzed from 197 patients including 394 treatment plans in combination of anatomical factors. The authors described the benefit of a deep inspiration breath hold over standard irradiation technique which has higher incidence of adverse cardiac effects, especially in left-sided breast cancer mainly for left descending artery irradiation. Authors claim that deep inspiration breath hold dosimetric is advantageous and this technique reduces the left descending artery irradiation significantly and should be always preferred. Overall, as authors mentioned in discussion section, that “topic is not novel this is the first study that built a model based on several FB anatomical data. The findings are useful and important for the clinical community, especially because the larger number of cancer patients where cardiotoxicity has been always a big concern in patients after radiotherapy. The manuscript is scientifically sound and written well. Manuscript can be accepted after following minor comment:

COMMENT 1 “Institutional Review Board Statement” and “Informed Consent Statement “ should be moved in Methods and Material section, before Patient selection

ANSWER 1 done. We added a paragraph called “Ethics” in the Methods and Material section

Reviewer 2 Report

Comments and Suggestions for Authors

The Authors present a  study to identify in a large dataset of patients the anatomical and treatment preplanning characteristics correlated with left descending artery (LAD) dose, in order to evaluate the amount of benefit of deep inspiration breath hold (DIBH) over standard treatment, and eventually guide selection of patients with left-breast cancer and prevent cardiotoxicity. 

The manuscript is interesting and well written but before proceeding to possible publication I would like the authors to clarify some points for me:

1)Why the minimum distance between LAD and tangential fields was measured only in two dimensions and the coronal section was not considered? It could be better specified which standardized parameter was used for this measurement. Could minimum distance measurement heterogeneity affect the results?

2)Why was the positive predictive value (PPV) of cardiac and lung volumes not taken into account and the volume of the LAD was not considered?

3)Maybe I missed it but which DHB technique was used? "All patients received a training session to establish the individual deep inspiration level and optimize compliance to DIBH." Are there no variables between the set-up and the treatment? Is what was measured in CT the same for all treatment sessions?

Thank you

Comments on the Quality of English Language

Minor editing of English language required

Author Response

We would like to thank the reviewer for the time spent reviewing our manuscript. We modified the manuscript according to the reviewer’s comments. All changes are tracked in the manuscript and additional section have been highlighted. We also provided a point by point response to the reviewers’comments.

Reviewer 2

The Authors present a study to identify in a large dataset of patients the anatomical and treatment preplanning characteristics correlated with left descending artery (LAD) dose, in order to evaluate the amount of benefit of deep inspiration breath hold (DIBH) over standard treatment, and eventually guide selection of patients with left-breast cancer and prevent cardiotoxicity. The manuscript is interesting and well written but before proceeding to possible publication I would like the authors to clarify some points for me:

COMMENT 1: Why the minimum distance between LAD and tangential fields was measured only in two dimensions and the coronal section was not considered? It could be better specified which standardized parameter was used for this measurement. Could minimum distance measurement heterogeneity affect the results?

ANSWER 1: We chose to measure LAD distance only in two dimensions as we wanted to offer an easy way to compute it using tangent open fields view. The same two physicians who reviewed indipendently LAD contours calculated the LAD distance in order to reduce the risk of heterogeneity of the measurements.

We better specified it in the material and methods section and in the discussion section as well.

 

COMMENT 2: Why was the positive predictive value (PPV) of cardiac and lung volumes not taken into account and the volume of the LAD was not considered

ANSWER 2: We calculated the PPV of the strongest predictor of LAD dose (either maximum or mean). Then we added the other parameters to increase the PPV. We did not include the LAD volume in this analysis as it can be more influenced by interobserver variability in delineation due to the small size compared to heart volume.