The ROCOCO performance scoring system translates dosimetric differences into clinically relevant endpoints: Comparing IMPT to VMAT in an example pilocytic astrocytoma dataset. (May 2021)

• Record Type: Journal Article
• Authors: in 't Ven, Lieke; Roelofs, Erik; Cubillos Mesías, Macarena; Compter, Inge; Klaver, Yvonne L.B.; Smeenk, Robert Jan; Janssens, Geert O.; Kaanders, Johannes H.A.M.; Fajardo, Raquel Davila; Oldenburger, Foppe; de Ruysscher, Dirk; Troost, Esther G.C.; Eekers, Daniëlle B.P.
• Is Part Of: Clinical and translational radiation oncology. Volume 28(2021)
• Page Start: 32
• Page End: 38
• Publication Date: 2021-05
• Subjects: Low grade glioma -- Pilocytic astrocytoma -- Organ at risk -- Proton therapy -- Cognition -- Scoring system; Cancer -- Radiotherapy -- Periodicals; Oncology -- Periodicals; Cancer -- Radiotherapy; Oncology; Radiation Oncology; Neoplasms -- radiotherapy; Translational Medical Research; Periodicals; Electronic journals; Periodicals; 616.9940642
• DOI: 10.1016/j.ctro.2021.02.006
• Languages: English
• ISSNs: 2405-6308

Abstract

Highlights: There is a dosimetric advantage for IMPT over VMAT in patients receiving radiation treatment for pilocytic astrocytoma. The novel RPSS is a practical scoring system making translation of dose differences into clinically relevant endpoints possible. Following the lower RPSS toxicity scores for IMPT, less toxicity is likely to be expected in patients treated with IMPT vs VMAT in this pilocytic astrocytoma cohort. Abstract: Background and purpose: Proton therapy is expected to outperform photon-based treatment regarding organs at risk (OAR) sparing but to date there is no method to practically measure clinical benefit. Here, we introduce the novel ROCOCO Performance Scoring System (RPSS) translating dose differences into clinically relevant endpoints and apply this to a treatment plan comparison of volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) in 20 pilocytic astrocytoma patients. Material and methods: The RPSS was developed on the basis of expert-based weighting factors and toxicity scores per OAR. The imaging datasets of 20 pilocytic astrocytoma patients having undergone radiotherapy were included in this in silico dosimetric comparison trial as proof of principle. For each of these patients, treatment plans to a total dose of 54 Gy (RBE) were generated for VMAT and IMPT and these were compared regarding radiation dose to the clinical target volume (CTV) and OARs. The RPSS was calculated for each treatment plan comparing VMAT and IMPT. Results: In 40 analysed treatment plans, the average and low dose volumes to various OARs were significantly reduced when using IMPT compared to VMAT ( p < 0.05). Using the RPSS, a significant difference between both treatment modalities was found, with 85% of the patients having a lower RPSS in favour of the IMPT plan. Conclusion: There are dosimetric differences between IMPT and VMAT in pilocytic astrocytoma patients. In absence of clinically validated NTCP models we introduce the RPSS model in order to objectively compare treatment modalities by translating dosimetric differences in potential clinical differences.