Integrated Multifunctional Laryngoscope for Medical Diagnosis and Treatment

Round 1

Reviewer 1 Report

The paper presents a new laryngoscope that integrates two imaging modes (OCT and white light endoscopy) and a treatment mode (laser ablation) into a common-path system with a single, shared probe. The paper contains very preliminary observations, done ex vivo, on a single porcine sample. The new laryngoscope may have clinical interest and deserves to be reported. However, the manuscript is not adequate. Important information is missing, the discussion is clearly insufficient, and the authors are drawing conclusions concerning early diagnosis of laryngeal cancer based on incorrect clinical criteria. Also, the study does not allow to draw the conclusions presented by the authors.

The authors address several times the question of a more accurate diagnostic:

• On the abstract they state that: This multifunctional laryngoscope has great potential for early diagnosis and accurate laser ablation surgery of laryngeal tumors.
• On the conclusions it is said that “The cross-sectional OCT image and superficial white light image could provide sufficient information for early diagnosis and accurate position for laser ablation surgery procedure”.

These two statements are acceptable since they are not definitive and just present a possibility or a potential. However, in lines 124 and 134, the authors present definitive statements:

• Line 124: “and the simultaneous acquired dual-mode images can improve diagnostic accuracy”.
• Line 132: “Based on the preliminary experimental results, a more accurate diagnose and accurately guided laser ablation surgery can be achieved by using this multi-modal endoscope”.

Possibly is just a case of bad English usage. “Can” is different from “could”. If that is not the case and the sentences are correct, these are very bold statements that, in my opinion, are not supported by the findings. In fact, such conclusions can never be obtained by the type of research presented in the paper. Conclusions on the accuracy of a diagnostic device require well-designed clinical trials and comparison with a reference method like histopathology. It is impossible to obtain this type of conclusions by examining just one non-pathological sample. The only conclusions that can be obtained with the reported study are on the imaged structures and on the possibility of imaging the ablation procedure.

So, the authors should carefully review their paper and remove any statements that are not supported by their findings and that cannot be tested by the presented study.

I also recommend a revision by a clinical expert on laryngeal cancer since there are comments on the paper that are clinically incorrect, particularly on the requirements for an early diagnosis.

The English usage should be improved. There are grammar errors, particularly concerning the correct use of verbs conjugation. I recommend a review by an English language expert.

Specific comments:

1. The used OCT unit is now fully specified. The authors provide the manufacturer but do not mention the model, making impossible to identify properly the OCT source.
2. The authors should discuss briefly why they selected an OCT with a central wavelength of 1310 nm instead of shorter wavelengths (1060 nm or 900 nm). Longer wavelengths have the advantage of lower scattering in the tissue, but the water absorption is much larger.
3. The authors report an imaging range of 10 mm for the OCT. If “imaging range” corresponds to the imaging depth, this value makes no sense. The imaging depth for 1310 nm OCT systems in biological tissues is usually below 2 mm and there are several reports concerning larynx examination with OCTs of the same wavelength that mention maximum imaging depths below 1.5 mm. Also, figure 3c does not provide evidence of a 10 mm imaging depth. Instead, the figure suggests an imaging depth around 1.5 mm. The authors should check this value. If there is no mistake, they must provide more information to verify their claim. What is the number of readouts of the photo diode during one sweep of the light source? What is the depth of focus of the OCT objective? What was he roll-off or the total attenuation over the imaging depth?
4. What is the OCT image (B-Scan) rate?
5. Although this information is provided in the text, the caption of figure 3 should identify all structures marked in the OCT B-Scan.
6. The authors write that “Many studies showed that malignant lesions would lead to the disappearance of BM. Therefore, BM is an indicator for early diagnosis”. I believe that this conclusion is not correct because basement membrane disruption is not a hallmark of early, superficial, stage T1 lesions. It occurs at later stages.
7. On the conclusion the authors state that “The efficiency and accuracy of this integrated multifunctional laryngoscope could be further improved by using some automatic image processing methods”. This sentence is too vague. Since the automatic image processing methods are not identified it is also a speculative sentence. Scientific papers should not contain speculations. If the authors wish to discuss improvements on the efficiency and accuracy of their instrument they should do it properly, identifying the items that must be improve, the imaging features that should be enhanced and the techniques that potentially could provide the desired improvements.
8. The paper lacks an appropriate discussion. The authors never address the limitations of their instrument. What are the technical factors that affect the quality of images obtained with OCT? Is the image quality influenced by factors such as the positioning and the steadiness of the probe? What would be the learning curve for the new instrument? Are motion artifacts from probe and patient a problem?
9. The discussion must also address properly what seems to be the main goal of the instrument: early diagnosis of laryngeal cancer. What the requirements for early diagnosis? Can it detect dysplastic lesions or early microinvasive tumors? The reported system has a lateral resolution of approximately 120 μm, which is not a good value (there are endoscopic OCT systems designed for larynx imaging that claim lateral resolutions around 10 μm). Is it possible to improve the lateral resolution of the instrument?

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors, in my opinion, the article titled “Integrated multifunctional laryngoscope for medical diagnosis and treatment” is an interesting paper but needs improvements.
Below, I present my major comments:

1.There is a lack of novelty in the presented paper. It is necessary to demonstrate the novelty of your investigation according to the recent state of the art because the use of OCT and lasers in medicine is well-known for years.
2. There is necessary to add more technical information about the probe, as well as the technical schema of it.
3. In my opinion it is necessary to expand the investigation for more samples. The probe was investigated only with one biological object what is too little.
4. The conclusion of the paper must be expanded. Please added the technical parameters of your probe comparing to other solutions presented in the literature.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors did a very good job correcting their manuscript and addressed adequately my concerns. In my opinion, the paper deserves publication since it reports the development of an innovative endoscope that includes co-axial OCT and white light imaging together with laser surgery function. This is a significant innovation, with relevant clinical potential that merits publication.

The manuscript could be improved in terms of English usage. This is the weaker point of the paper and, unfortunately, affects its readabilty. If possible this should be addressed before final publication.

Author Response

We would like to thank the reviewer for the suggestion. We have used the English editing service from MDPI to improve the English usage in the manuscript.

Reviewer 2 Report

Dear Authors,

I will recommend this manuscript to be accept in present form.

Author Response

We would like to thank the reviewer for the careful review.