Evaluation of the Key Advantages between Two Modalities of Boronophenylalanine Administration for Clinical Boron Neutron Capture Therapy Using an Animal Model
Round 1
Reviewer 1 Report
This is an original and contributory paper that addresses an issue of great significance in BNCT therapeutic efficacy, i.e. the strategy used to administer the boron compound. Although one step (OSI) and two step (TSI) infusions have been used, this is the first time that the advantages and disadvantages of each strategy have been scientifically compared in an animal model. The benefits of the TSI are suggested based on this study.
I consider the manuscript worthy of publication once the following minor issues have been addressed:
1) I would ask the authors to discuss the potential effects of OSI vs TSI using the same TOTAL dose of boron rather than 400 mg / kg (OSI) vs 500 mg / kg (TSI).
2) Oral mucosa is an important tissue to assess because it is dose-limiting (it gives rise to the unwanted side-effect mucositis). The authors analyze tongue but they do not analyze oral mucosa. Please discuss.
3) Please re-write and clarify the following paragraph:
T/B ratio was an independent of infusion time at 1 h after the end of infusion with the same infusion rate, but the different total BPA dose. At the same total BPA dose, whether boron concentrations in the tumor or blood at a dose rate of 250 mg/kg/h were the same as those at a dose rate 245 of 125 mg/kg/h [33].
4) Please mention the possible role of boron microdistribution in the benefits achieved by TSI vs OSI.
Author Response
Thank you for your comments. All comments have been responded point-by-point. Please find the author's notes file.
Author Response File: 
Author Response.docx
Reviewer 2 Report
General comments
This manuscript seems to be pretty interesting for researchers with some BNCT experience like me.
However, I feel very strange that administered total dose of BPA is different between OSI and TSI methods in this study. As is shown in this manuscript, in clinical BNCT, whether with OSI or TSI method, the amount of BPA administered is the same at 500 mg/kg. Given a fixed dose of BPA available, the question is how it should be administered in the most useful way. TSI is considered to be the mode of administration of BPA that was developed to clarify what mode of administration is the most useful to some extent when the administered total dose of BPA is the same. The main premise is that the administered total dose of BPA remains the same and does not change. It is quite natural that TSI, which consists of OSI consisting only of first step infusion and second step infusion, shows greater usefulness and advantages in biodistribution study after BPA administration. You have to clearly explain why the total dosage was different so that the readers including me can fully understand. If this point cannot be fully and clearly explained, this manuscript is never accepted for publication.
Furthermore, also in this kind of study, concerning an anti-tumor effect through BNCT, the data on the anti-tumor effect after neutron beam irradiation to tumors after BPA administration have to be added and shown. There should be some discussion and consideration concerning the mode of administration of BPA, based on the data not only concerning biodistribution study but also concerning antitumor effects after neutron beam irradiation to tumors after BPA administration.
In addition, the following specific comments must be appropriately addressed and responded to.
Needless to say, when the author re-submits the revised version of this manuscript, the point-by-point response letter that responds to all the comments and/or advices given by the reviewers has to be submitted. Unless the author does so, I also never accept the revised manuscript for publication.
Specific comments
Introduction
The phrase “The accumulated effect” is pretty unfamiliar to general readers. Thus, you have to explain “the accumulated effect” more clearly and in more detail so that general readers can easily understand.
Materials and Methods
The more total dose of BPA was administered in TSI than OSI method. Therefore, it is natural that higher boron-10 concentrations were distributed in many organs and blood in TSI than OSI method. To match the clinically adopted administering regimen of equalizing total BPA doses, in OSI method, BPA should be administered at the dose of 25 mg/kg/min. The reason why 20 mg/kg/min was employed must be explained and described appropriately and in detail.
Results
Figure 4, To make it easily to understand, “OSI” and ”TSI” should be displayed in each graph.
Discussion
Tumor heterogeneity significantly affects the intratumoral distribution of boron-10 from BPA. However, you just used SAS tumors only. Referring to other tumors, discussion and consideration should also be given to the impact of tumor heterogeneity. Discussions and considerations regarding tumor heterogeneity also has to be described.
Again, needless to say, when the author re-submits the revised version of this manuscript, the point-by-point response letter that responds to all the comments and/or advices given by the reviewers has to be submitted. Unless the author does so, I never accept the revised manuscript for publication.
Author Response
Thank you for your comments. All comments have been responded point-by-point. Please find the author's notes file.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Please find and read carefully the comment shown in the last page in the attached file named "cells-1866117-coverletter.-AddedWithComments. You have to respond to the comment. If you do not respond appropriately to the comments, I cannot help rejecting publication of your manuscript.
Comments for author File: Comments.docx
Author Response
All comments have been responded point by point. Please see the attachment file. New responses have been shown on the page 7 and 8.
Author Response File: Author Response.docx
Round 3
Reviewer 2 Report
I don’t ask you to discuss pharmacokinetics for 500 mg/kg of PBA administered in OSI. I ask you to show the really obtained data when 500 mg/kg of PBA was administered in OSI method, and compare the really obtained data between PBA administration at the dose of 500 mg/kg in OSI method and BPA administration of 400 mg/kg plus the second step infusion in TSI method. You have to add the really obtained data when 500 mg/kg of PBA was administered in OSI method. And, you have to compared the really obtained data when BPA was administered at the dose of 500 mg/kg in OSI method and at the dose of 400/mg as the first step infusion plus the second step infusion in TSI method. Anyway, show the really obtained data! If you don’t show the really obtained data, I never accept this manuscript for publication.
Respond to the above-mentioned comment.
(The same commet is shown in the last page of the attached file.)
Comments for author File: 
Comments.pdf
Author Response
Thank you for your comments. The response has been shown on page 9 in attached file. Please find it.
Author Response File: Author Response.docx
