Safety and Efficacy of 2D Brachytherapy vs. 3D Image-Guided Adaptive Brachytherapy for Locally Advanced Cervical Cancer—A Single Institution Retrospective Study

Round 1

Reviewer 1 Report

The authors compared safety and efficacy between two Brachytherapies for Locally Advanced Cervical Cancer.

 

Comments

1.   Is there discontinuation of the treatment or loss of follow-up existing ? How would these influence toxicity and efficacy ? Authors are suggested to clarify and conduct a sensitivity analysis.

2.  Why is ordered logistic regression used ? The outcome variable seems not to be ordinal.

3.   In table 1, continuous variables are usually displayed as the mean(std), especially for age.

4.  For Figure1-2, please provide extra statistics, including censoring rate, events, median survival time.

Author Response

Please see attachment

Author Response File: Author Response.docx

Reviewer 2 Report

I read your paper with great interest. The authours objective was to compare institutional experience/outcomes of 2D BT vs 3D BT.

I think this is worthy of publication but I have a few comments for consideration:

Methods page 3 - side effects were collected using CTCAE, since this is a retrospective study, were side effects graded via retrospective chart review, or is toxicity prospectively collected during/after RT at your institution, can you elaborate upon this? The use of PET, CT/MR post RT - is this part of a study protocol or is this your routine surveillance strategy?

Study endpoints page 3 - acute toxicity classified as up to 6 months post RT, however we typically defined acute toxicity as within 90 days/3 months of RT, can you clarify how you came about your end point. I would encourage you to evaluate your endpoints with acute = up to 3 months, and late as >3 months to align with studies such as EMBRACE.

 

Results - there are only 48 patients treated with 3D BT and the follow up for this cohort was 25 months; however, clinical outcomes are reported for 3 years and 5 years. Would it be better to evaluate LC for example, at 2 years, as it may be more meaningful. I am also referring to Figure 1A and 1B.

14 had ring/cylinder/needles, what number/% of patients specifically had interstitial brachytherapy. I would assume numbers are too small to do any meaningful analysis?

 

For table 1 you comment upon BT dose, but there is no dosimetry provided for the cohorts such as HRCTV D90, rectum/bladder D2cc, vaginal D2cc or ICRU RV point (surrogate for vaginal toxicity). In addition to comparing toxicity between cohorts it would be good to describe/compare dosimetric endpoints as toxicity predictors.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors solved all the issues. Thank you for your response.