Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for the submission.

In this study, the size of nidus  and eccentricity is closeley associated with the clinical success.  Those results aregenerally agreed .

But in the clinical situation, the locations of  active tip in the nidus could be varied and they  can be  another factor .

This comment may be added in to improve the discussion. 

 

Thannk you.

Author Response

Reviewer 1 Comment:

In this study, the size of the nidus and eccentricity is closely associated with clinical success. Those results are generally agreed. But in the clinical situation, the locations of the active tip in the nidus could be varied, and they can be another factor. This comment may be added to improve the discussion.

Author Response:

We sincerely thank the reviewer for this valuable and insightful comment.
We fully agree that the position of the active tip within the nidus may vary in clinical practice and can potentially influence the completeness of thermal ablation. In our study, all ablations were performed by the same interventional radiologist under coaxial CT guidance, ensuring consistent central intranidal positioning of the electrode or antenna. Therefore, this variable was relatively standardized within our cohort.

Nevertheless, we acknowledge that minor deviations in active-tip placement could affect heat distribution, especially in eccentric or elongated nidus geometries, potentially influencing treatment success or recurrence risk. In accordance with the reviewer’s suggestion, we have added the following statement to the Discussion section to reflect this important consideration:

“In addition to lesion morphology, small variations in the position of the active tip within the nidus may influence ablation completeness and thereby clinical success, particularly in elongated or eccentrically shaped lesions.”

We are grateful for the reviewer’s constructive feedback, which has helped improve the depth and completeness of our discussion.

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

 

Thank you for your submission. The topic is clinically relevant, and the study provides useful comparative data on RFA versus MWA in the treatment of osteoid osteoma, with robust follow-up. The manuscript is generally well organized and supported by appropriate methodology. However, some revisions are required to enhance clarity, strengthen scientific rigor, and improve readability.

 

1. Introduction

 

The introduction provides a broad overview but is partially redundant. Please streamline the background to clearly identify the existing knowledge gap and emphasize why a head-to-head comparison between RFA and MWA is clinically necessary.

Some references are repeated, and the transition between paragraphs could be improved to avoid narrative overlap.

 

2. Methods

 

Although the procedural details are comprehensive, the section is overly long and could be made more concise.

The retrospective design and the fact that RFA was performed before the introduction of MWA should be discussed as a potential source of temporal or selection bias. Clarification on whether any matching criteria were used would improve transparency.

Please better define and reference the eccentricity index (EI) and its clinical rationale within the context of osteoid osteoma ablation.

 

3. Results

 

The data presentation is clear; however, some numerical findings are repeated both in the text and in the tables. Consider summarizing the narrative and referring to the tables to avoid redundancy.

Please report absolute numbers alongside percentages consistently.

 

4. Discussion

 

The discussion is informative but could be made more concise by limiting general background statements and focusing more on how your findings add new insights to current literature.

It would be helpful to provide more practical recommendations for clinical decision-making based on nidus size and morphology.

The impact of nidus size ≥10 mm as a prognostic factor is a major strength of the study and should be highlighted earlier in the discussion.

 

5. Figures and Tables

 

Overall presentation is acceptable; however, ensure that figure labels and legends are clearly readable in the final layout.

Consider improving the visual quality of Figure 2, where text appears small.

 

6. Language and Style

 

The English language is generally understandable but requires revision for grammar, syntax, and redundancy. Several sentences are long and could be simplified for better readability.

I recommend a professional English language editing service to enhance clarity and fluency.

 

Conclusion

 

The manuscript addresses an important clinical question and provides valuable evidence. With revisions focused on improving clarity, reducing redundancy, and better highlighting the novelty of the findings, the manuscript would be suitable for publication.

 

Comments on the Quality of English Language

The manuscript is generally understandable; however, the quality of English should be improved to enhance clarity and readability. Several sentences are overly long or contain repetitive wording, which may obscure the key scientific message. Minor grammatical errors, incorrect verb tenses, and inconsistent terminology are present throughout the text. A thorough language revision, preferably by a professional editing service, is recommended to ensure scientific accuracy and fluency.

Author Response

Reviewer 2 

General Comment

“The topic is clinically relevant and the study provides useful comparative data on RFA versus MWA. However, some revisions are required to enhance clarity, strengthen scientific rigor, and improve readability.”

Response:
We thank the reviewer for the positive assessment and constructive feedback. The entire manuscript was carefully revised to improve clarity, conciseness, and scientific rigor. The English language has been refined throughout by a professional editor to enhance fluency and readability. Specific revisions are addressed below.

1. Introduction

“The introduction provides a broad overview but is partially redundant. Please streamline the background to clearly identify the existing knowledge gap and emphasize why a head-to-head comparison between RFA and MWA is clinically necessary. Some references are repeated, and transitions between paragraphs could be improved.”

Response:
We revised the Introduction to reduce redundancy, improve transitions, and more clearly emphasize the rationale for the study. Repeated references were removed, and the final paragraph now explicitly highlights the lack of adequately powered comparative studies and the clinical importance of defining modality-specific prognostic factors.

Changes made:

• Consolidated overlapping statements about RFA’s established efficacy and MWA’s emerging potential.

• Clarified the imbalance in existing evidence (large RFA series vs. limited MWA data).

• Added a closing sentence that frames the study as the largest single-center, directly comparative series.
  (See pp. 2–3, lines 65–98 of the revised file.)

2. Methods

“Although the procedural details are comprehensive, the section is overly long and could be made more concise.”

Response:
The Materials and Methods section was streamlined by merging repetitive procedural descriptions and summarizing standard steps (e.g., sedation, monitoring, post-procedure care). Only technique-specific details were retained for clarity.
(See pp. 4–6.)

“The retrospective design and the fact that RFA was performed before the introduction of MWA should be discussed as a potential source of temporal or selection bias. Clarification on whether any matching criteria were used would improve transparency.”

Response:
We explicitly discussed these aspects in both the Methods and Discussion sections:

“Interpretation is limited by the retrospective, single-center design and temporal imbalance, as RFA was performed before MWA introduction. No formal matching or propensity scoring was applied; however, baseline characteristics were compared to ensure overall group similarity.”
(Added at end of Discussion, p. 17.)

“Please better define and reference the eccentricity index (EI) and its clinical rationale within the context of osteoid osteoma ablation.”

Response:
We revised the EI definition to clarify its calculation and rationale, adding relevant references (Baal et al. 2019; Tung et al. 2025):

“The eccentricity index (EI) was calculated as the ratio of the largest to the smallest orthogonal nidus diameter on CT, providing a quantitative measure of geometric asymmetry. This parameter was adapted from prior CT-based RFA studies that identified elongated morphology (EI ≥ 3) as a potential predictor of treatment failure.”
(See Methods, p. 6.)

3. Results

“The data presentation is clear; however, some numerical findings are repeated both in the text and in the tables. Consider summarizing the narrative and referring to the tables to avoid redundancy.”

Response:
Redundant numerical details were removed. The text now highlights only the principal results, with direct references to tables for detailed data (Tables 1–6).
(See pp. 8–10.)

“Please report absolute numbers alongside percentages consistently.”

Response:
All results are now reported as *n (%) * consistently throughout the manuscript and tables.

4. Discussion

“The discussion is informative but could be made more concise by limiting general background statements and focusing more on how your findings add new insights to current literature.”

Response:
The Discussion was shortened by ~15%, removing general literature review material. The revised version emphasizes (a) comparative findings between RFA and MWA, (b) the clinical impact of nidus size ≥ 10 mm, and (c) the novel inclusion of EI as a morphological factor.
(See pp. 12–16.)

“It would be helpful to provide more practical recommendations for clinical decision-making based on nidus size and morphology.”

Response:
We added a paragraph summarizing procedural recommendations:

“Our results underscore the importance of individualized procedural planning based on nidus morphology. Lesions ≥ 10 mm or elongated nidi may benefit from overlapping or multi-cycle ablations to ensure complete coverage, whereas superficial lesions require protective measures against thermal injury.”
(See Discussion, p. 16.)

“The impact of nidus size ≥ 10 mm as a prognostic factor is a major strength of the study and should be highlighted earlier in the discussion.”

Response:
We relocated and emphasized the sentence discussing nidus size ≥ 10 mm at the beginning of the Discussion, presenting it as the primary prognostic finding.
(See first paragraph of Discussion, p. 12.)

5. Figures and Tables

“Ensure that figure labels and legends are clearly readable in the final layout. Consider improving the visual quality of Figure 2, where text appears small.”

Response:
Both figures were reformatted at higher resolution with enlarged axis labels and legend fonts. Figure 2 text size was increased for better readability.
(Revised figures attached in the resubmission package.)

6. Language and Style

“The English language is generally understandable but requires revision for grammar, syntax, and redundancy.”

Response:
The manuscript underwent full English-language editing by a native-speaking professional editor (certificate attached). Long sentences were divided for clarity, and terminology was standardized (e.g., “nidus diameter,” “clinical success,” “eccentricity index”).
(Entire manuscript revised.)

7. Conclusion

“With revisions focused on improving clarity, reducing redundancy, and better highlighting novelty, the manuscript would be suitable for publication.”

Response:
We revised the Conclusion to succinctly summarize the clinical implications:

“Both RFA and MWA are safe and effective for osteoid osteoma. MWA shortens ablation time but does not reduce overall procedure duration. Treatment should be individualized according to lesion-specific factors—particularly nidus size ≥ 10 mm and geometry—rather than energy modality.”
(See p. 17.)

Reviewer 3 Report

Comments and Suggestions for Authors

Nice overview. Some minor remarks:

- You perfom a MRI 1 month after the procedure if the pain persists. In our hospital most patients with a residual osteoid osteoma present with recurrence of pain usually several months after the procedure after initial benefit of the procedure. Is this also your experience? Can you comment on this? And after one month can you still expect signal alterations due to the procedure?
- If there is no clear advantage of MWA or RFA, which would you recommend? Based on which criteria? Location? Size of the nidus? Cost of the electrode?
- You mentioned an ablation time of 5-6 minutes at 90 degrees Celsius using RFA. Is this time and temperature based on earlier reserach or experience based by the interventional radiologist? 

Author Response

REVİEWER 3 RESPONCES

Comment 1

You perform an MRI 1 month after the procedure if the pain persists. In our hospital most patients with a residual osteoid osteoma present with recurrence of pain usually several months after the procedure after initial benefit of the procedure. Is this also your experience? Can you comment on this? And after one month can you still expect signal alterations due to the procedure?

Response:
We fully agree with your observation and share a similar experience in our clinical practice. Therefore, we do not perform routine MRI in any patient after ablation. MRI is requested only when there is no evident clinical improvement, as also reflected in our definition of clinical success.
To avoid potential misunderstanding, we have revised the “Optional Research MRI” section of the manuscript to clarify that this imaging was performed solely in a predefined subset of patients for research purposes and did not influence routine management.
In our experience, the first four months represent the critical period for evaluating residual nidus. The vast majority of our patients achieve complete pain relief within the first month—consistent with previous literature and your clinical experience.
True recurrences in our cohort were observed much later, typically around the 9th to 12th month of follow-up, supporting the view that recurrence generally occurs after an initial pain-free interval rather than in the early post-procedural phase.

Comment 2

If there is no clear advantage of MWA or RFA, which would you recommend? Based on which criteria? Location? Size of the nidus? Cost of the electrode?

Response:
Our data demonstrated comparable technical and clinical success between MWA and RFA, with MWA showing shorter ablation times but no meaningful difference in total procedure duration.
During the early years of our study, RFA was our standard technique, as clinical experience with MWA was still limited. As more evidence accumulated and our institutional experience increased, we gradually transitioned to MWA, which we continue to use as our current routine approach.
In Türkiye, the national reimbursement system provides similar coverage for both RFA and MWA; therefore, there is no cost-effectiveness difference between the two modalities. For this reason, economic factors did not influence our decision-making, and this point was not included in the comparative analysis. We have also noted this temporal shift between modalities as a methodological limitation in the revised manuscript.

Currently, our selection criteria are individualized based on lesion characteristics rather than device type:

• Nidus size and geometry: Larger (≥10 mm) or high-eccentricity lesions require meticulous probe positioning and, if necessary, overlapping or multi-cycle ablation.

• Location and safety margin: For superficial or juxta-articular lesions, conservative energy delivery and protective techniques (e.g., hydrodissection) are preferred.

Hence, with comparable outcomes, our current preference for MWA is guided by accumulated experience and procedural efficiency, not by cost or device availability.

Comment 3

You mentioned an ablation time of 5–6 minutes at 90 °C using RFA. Is this time and temperature based on earlier research or experience of the interventional radiologist?

Response:
The RFA parameters used in our study—temperature-controlled ablation at 90 °C for 5–6 minutes with a Cool-tip™ system—are based on both prior literature and longstanding institutional experience. These settings have been consistently reported in previous RFA series on osteoid osteoma and are part of our standardized departmental protocol. The generator automatically modulated power output to maintain the target temperature, ensuring complete intranidal ablation once optimal probe positioning was achieved.