The impact of bone marrow sparing on organs at risk dose for cervical cancer: a Pareto front analysis.

Background and purpose

To quantify the increase in bladder and rectum dose of a bone marrow sparing (BMS) VMAT strategy for primary treatment of locally advanced cervical cancer (LACC).

Materials and methods

Twenty patients with stage IB-IVA cervical cancer were selected for this study. The whole Pelvic Bones (PB) was taken as substitute for bone marrow. For every patient, Pareto-optimal plans were generated to explore the trade-off between rectum, bladder, and PB mean dose. The PB mean dose was decreased in steps of 1 Gy. For each step, the increase in rectum and bladder mean dose was quantified. The increase in mean dose of other OAR compared to no BMS was constrained to 1 Gy.

Results

In total, 931 plans of 19 evaluable patients were analyzed. The average [range] mean dose of PB without BMS was 22.8 [20.7-26.2] Gy. When maximum BMS was applied, the average reduction in mean PB dose was 5.4 [3.0-6.8] Gy resulting in an average mean PB dose of 17.5 [15.8-19.8] Gy. For <1 Gy increase in both the bladder and the rectum mean dose, the PB mean dose could be decreased by >2 Gy, >3 Gy, >4 Gy, and >5 Gy for 19/19, 13/19, 5/19, and 1/19 patients, respectively.

Conclusion

Based on the comprehensive three-dimensional Pareto front analysis, we conclude that 2-5 Gy BMS can be implemented without a clinically relevant increase in mean dose to other OAR. If BMS is too dominant, it results in a large increase in mean dose to other OAR. Therefore, we recommend implementing moderate BMS for the treatment of LACC patients with VMAT.

Informations de copyright

Copyright © 2023 Kuipers, Godart, Corbeau, Sharfo, Breedveld, Mens, de Boer, Nout and Hoogeman.

Déclaration de conflit d'intérêts

RN reports to have received research grants from Dutch Cancer Society, Dutch Research Council, Elekta, Varian Medical Systems, and Accuray, and a research grant for this work by Varian Medical Systems. MH reports to have received research grants from Varian Medical Systems and Dutch Cancer Society and clinical advisory membership of Accuray. JG reports to have received a research grant for this work by Varian Medical Systems. SdB reports to have received a research grant for this work by Varian Medical Systems. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. This study received funding from Varian Medical Systems. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.