Analysis of Skeletal-Related Events in a Liaison Treatment for Metastatic Spinal Tumors: A 10-Year Retrospective Study

Dear Shyam Sundar Sah, MD, and Abhishek Kumbhalwar, PhD,

We sincerely appreciate the thoughtful and constructive comments provided by Sah et al. regarding our study, “Analysis of Skeletal-Related Events in a Liaison Treatment for Metastatic Spinal Tumors: A 10-Year Retrospective Study.”¹⁾ We value the opportunity to clarify several methodological points and to further discuss the implications of our findings within the broader context of metastatic spine care.

1. Use of SINS Thresholds and Risk Stratification

We have undoubtedly relied solely on SINS for evaluating spinal instability up to now.

We investigated a focused retrospective review of SRE cases that occurred in patients with low SINS scores (<6), which are generally considered stable. All patients who developed SREs despite low SINS scores had junctional involvement, corresponding to three points in the SINS Location category. No SREs were observed in patients with low SINS scores and non-junctional locations. This finding suggests that even when the overall SINS score is low, junctional lesions may represent a higher-risk subgroup for SREs. We have revised the manuscript to highlight that special attention is warranted for junctional spine involvement, and that reliance on the total SINS score alone may underestimate risk in these patients. We further discuss the implications of this finding for future implementation, emphasizing the need for closer monitoring and multidisciplinary evaluation of junctional lesions, even when classified as stable by SINS.

2. Timing of Multidisciplinary Evaluation

Sah et al. appropriately highlight the potential delays inherent in monthly liaison meetings. We acknowledge that treatment timing is a critical factor, particularly for patients with ESCC grade ≥II, who may experience rapid neurological deterioration. In practice, however, our liaison system did not rely solely on the monthly meeting cycle. Patients with progressive neurological symptoms, intractable pain, or radiological evidence of instability were escalated to urgent surgical or radiation oncology consultation outside of the scheduled meeting. Our retrospective data set did not include precise time-to-treatment metrics, representing a limitation we noted in the Discussion. Incorporating a structured urgency-based triage pathway, such as early spine surgery assessment within 48 hours for newly identified ESCC, aligns with our current direction of system refinement and is consistent with international guidelines. We appreciate this point and agree that real-time triage algorithms would enhance future multidisciplinary models.

3. Patients without Previously Diagnosed Malignancy

It is undoubtedly a limitation of this study that focuses primarily on delays in referrals from other facilities as the main cause of delayed diagnosis.

A point for improvement in this paper is that it does not sufficiently explore the underlying reasons for the delayed diagnosis. We will examine this point further in the next study.

In summary, we appreciate the careful review and constructive feedback offered by Sah et al. Their comments help clarify the contextual limitations of our retrospective design and highlight meaningful directions for improving liaison-based spine care. We believe that ongoing collaboration between spine surgeons, oncologists, radiologists, and primary care providers will be essential to reducing preventable SREs and improving patient outcomes.

Sincerely,

Conflicts of interest: The authors declare that there are no relevant conflicts of interest.