Comparison of Robotic and Open Lobectomy for Lung Cancer in Marginal Pulmonary Function Patients: A Single-Centre Retrospective Study

Round 1

Reviewer 1 Report

Dear Authors,

I read with enthusiasm the paper entitled "Can robotic lobectomy have an impact the postoperative outcomes of marginal pulmonary function patients?".

1) Please add the intraoperative complication rate of both arms (open vs RATS) and in the two timeline groups (RATS Si vs RATS Xi). Please mention these results in the table and also in the discussion paragraph.

2) May you improve the data related to the PFT with the resulted median or mean value of DLCO% and FEV1% in the tables?

3) Please specify if the operations were performed by different surgeons on the patients enrolled in the two arms (open vs RATS).

4) If possible, specify what kind of thoracotomy was the standard (e.g., lateral, postero-lateral, muscle sparing...etc.) 

5) As you stated in the result paragraph, the RATS group included more early stages than the open group. Did you study this aspect as confounding facto in the regression analysis?

6) Some abbreviations should be explained in the tables.

Good job.

Minor corrections are needed as comas, particles, and preopsitions.

Author Response

Dear Reviewer,

Thank you very much for the appreciation of our paper and for the interesting and conscientious suggestions. I will reply to comments in sequence:

• The intraoperative complication rate of the two groups is inserted in the text (line 169). No difference was observed between Si and Xi groups
• FEV1 and FEV1/FVC values are reported in table 1. Unfortunately, the information on DLCO value is not available for all the patients.
• The information about the surgeons who performed the operations (line 140) and the thoracotomy (line 139) has been added to the text
• The TNM stage was one of the possible confounding factors evaluated. The statistical analysis showed gender” and “upper lobectomy” as the only confounding factors.
• The missing abbreviations are inserted in the text

Reviewer 2 Report

Thank you for submitting this interesting and informative manuscript to Current Oncology. I was pleased to receive it as a reviewer.

While your manuscript provides valuable insights in an important thoracic surgical topic, there are some areas that could be refined to further enhance the quality and impact of the work. Here are some respectful suggestions that could potentially improve the paper if you choose to implement them:

Title

- The title could be modified to reflect the study’s design and objectives more accurately. For instance, a title like “Impact of robotic versus open lobectomy on postoperative outcomes in lung cancer patients with marginal pulmonary function: A single-centre, retrospective study” underscores the study's primary focus and methodology.

Introduction

- To enhance the manuscript's background, providing a more comprehensive rationale for focusing on postoperative complications as opposed to long-term oncological outcomes would be beneficial. This could be reinforced by citing further studies highlighting the prognostic significance of mitigating perioperative morbidity.

Methods

- Your observation about using an absolute value of FEV₁ < 1.5 L to identify patients with poor respiratory function is noteworthy. While this cut-off is informative, it may not capture the full representation of the patient population as effectively as percent predicted values. Additionally, it is important to acknowledge that DLCO is a well-established and validated prognostic factor for morbidity and mortality following lobectomy. To enhance the robustness of the study's methodology, it would be advisable to include percent predicted values of FEV₁ and DLCO. Including these metrics aligns with the recommendations of both the ACCP and the ERS/ESTS for preoperative pulmonary evaluation for lung resection. This would not only enhance the methodology but also increase the clinical relevance and comprehensiveness of the study.

- To provide readers with a more informative assessment of the safety of the surgical approaches under examination, it would be advantageous to consider reporting 90-day mortality data instead of the current 30-day mortality data. This extension would offer a more comprehensive perspective on postoperative outcomes.

- For the sake of clarity, the manuscript could benefit from the inclusion of a visual flow diagram illustrating the screening process, enrolment of subjects, distribution into intervention groups, and the various analysis sets. Such a diagram would enhance the reader's understanding of the experimental design.

- To provide valuable context, it would be beneficial to explain the rationale behind the selection of December 2019 as the cutoff for study accrual. Elaborating on this aspect would help readers better understand the timing and scope of the study.

- Addressing potential confounding variables, it would be prudent to describe any standardization of postoperative care that was implemented between the two surgical groups. This would contribute to a more thorough understanding of the study's methodology and potential sources of bias.

- If the sample size allows for it, conducting subgroup analyses by lung function strata could yield more nuanced insights. This approach would offer a deeper understanding of how patients with varying degrees of lung function are affected by the surgical approaches under investigation.

Results

- To provide readers with a more comprehensive understanding of the morbidity profiles in each group, it would be valuable to include a table that details the specific postoperative complications recorded in both groups.

Discussion

- Addressing the safety of longer operative times associated with the robotic approach is a relevant consideration, particularly since the duration of surgery has been linked to complications in some studies. Providing insights into this aspect would help mitigate potential concerns and contribute to a more comprehensive analysis of the findings.

- Including information about any changes in pain management practices over the study period is another pertinent factor to consider. Such changes could have influenced patient outcomes and acknowledging them in the discussion would be both relevant and informative.

- Discussing the cost implications of the robotic approach and whether its potential benefits might offset any cost differentials is a point of interest for both readers and policymakers. This economic perspective could shed light on the broader implications of the study's findings.

Conclusions

- The concluding sentence suggesting that the evolution of technology in the robotic system, in conjunction with high-volume surgical activity, can enhance the postoperative outcomes of frail patients may not be directly supported by the study's findings and could potentially be omitted. It is worth noting that frailty is a well-defined clinical term, and since this factor was not specifically investigated in the present study, the statement may not be directly relevant to the research and its conclusions.

Overall, these suggestions aim to enhance the manuscript's quality and impact for clinicians and researchers considering adoption of robotic approaches for patients with lung cancer and impaired pulmonary function. I believe that implementing some of the above suggestions would make your important work even stronger.

Author Response

Dear Reviewer, 

Thank you for taking the time to review our manuscript and for your interesting feedback

Please consider the following list explaining our answer to your comments:

- Thanks for your suggestion, we have modified the title.

- We argue the rationale for focusing on postoperative complications according to your suggestion (line 51)

-We added the value of percent predicted FEV1 in table 1. Unfortunately, DLCO value is not reported, because not available for all the patients. Moreover, the DLCO value is recognized as a prognostic factor of long-term survival after lung resection, so we didn’t evaluate this data being the aim of this study the analysis of the impact of the robotic approach on short-term outcomes, taking for granted the similar long-term results of the two different surgical approaches. We discuss this point in line 312

- we modified the text: the post-operative 90-day mortality is described in line 184.

- the visual flow diagram of the study design is inserted in materials and methods

- The postoperative management was similar in the two groups over the years and it is specified in the text (line 115).

- Confounding factors were assessed, further analyses were not done due to the small size of the sample

- The details of post-operative complications were reported in table 2.

- Many studies in the literature report a lower rate of complications after robotic surgery, despite longer operating time (line 322)

- There was a similar pain management over the years among the two groups (line 115)

- The costs related to robotic surgery were not evaluated in this study, although we have an economic policy linked to the presence of a multispecialty robotic surgical center which allows us to have similar cost between robotic and open procedures, thanks to the high volumes and high-complexity surgery; however, the articles already published demonstrate the sustainability of robotic surgery in thoracic field

• Patel YS, Baste JM, Shargall Y, Waddell TK, Yasufuku K, Machuca TN, Xie F, Thabane L, Hanna WC. Robotic Lobectomy is Cost-Effective and Provides Comparable Health Utility Scores to Video-Assisted Lobectomy: Early Results of the RAVAL Trial. Ann Surg. 2023 Aug 8
• Nguyen DM, Sarkaria IS, Song C, Reddy RM, Villamizar N, Herrera LJ, Shi L, Liu E, Rice D, Oh DS. Clinical and economic comparative effectiveness of robotic-assisted, video-assisted thoracoscopic, and open lobectomy. J Thorac Dis. 2020 Mar;12(3):296-306
• Shah PC, de Groot A, Cerfolio R, Huang WC, Huang K, Song C, Li Y, Kreaden U, Oh DS. Impact of type of minimally invasive approach on open conversions across ten common procedures in different specialities. Surg Endosc. 2022 Aug;36(8):6067-6075

- The term frail has been modified with “high risk”

Round 2

Reviewer 2 Report

Thank you for the attention and consideration you have shownto my suggested revisions for your manuscript. It is clear that a significant amount of effort and thought has been directed towards the refining of your work, integrating the feedback provided during the peer review process. The resulting modifications demonstrate a thorough approach, and significantly improve the overall quality of your manuscript. I look forward to witnessing the impact your paper will have on the academic community.

Author Response

Thank you.