RBE-weighted dose in carbon ion therapy for ACC patients: Impact of the RBE model translation on treatment outcomes

Silvia Molinelli*, Maria Bonora, Giuseppe Magro, Silvia Casale, Jon Espen Dale, Piero Fossati, Azusa Hasegawa, Alfredo Mirandola, Sara Ronchi, Stefania Russo, Lorenzo Preda, Francesca Valvo, Roberto Orecchia, Mario Ciocca, Barbara Vischioni

*Korrespondierende:r Autor:in für diese Arbeit

Publikation: Beitrag in Fachzeitschrift (peer-reviewed)Artikel in Fachzeitschrift

18 Zitate (Scopus)


Purpose/objective: The purpose of this study is to assess the impact of the conversion scheme for relative biological effectiveness (RBE)-weighted dose (DRBE), implemented at our center, on treatment outcomes of adenoid cystic carcinoma (ACC) patients. Material/methods: Treatment plans of 78 ACC patients, optimized with the Local Effect Model (LEM), were recalculated with the modified Microdosimetric Kinetic Model (mMKM). DRBE to 95%, 50% and 2% (DV%) of the clinical target volume (CTV), were selected as relevant parameters to compare LEM and mMKM DRBE. The pattern of failure of ACC treatments was analyzed in relation to uncertainties involved in the DRBE translation methodology. Results: mMKM recalculations of LEM plans, optimized to a prescription dose of 68.8 Gy(RBE), showed a D50% 8% higher, on average, than the expected value (60.8 Gy(RBE)), closer to the most frequently used mMKM prescription DRBE (64 Gy(RBE)). D95% and D2% deviations, with respect to the optimization goals in the two RBE systems, increased of 0.5% and 14.2%, respectively, due to the steeper mMKM RBE variation along the beam path. Local recurrences were mainly (63%) reported in areas where CTV coverage was not satisfactory in the original LEM plan and the mMKM analysis showed that OARs constraints were too conservative. Conclusion: No case of local recurrence could be explained by inadequate mMKM target coverage that was not already present in the LEM plan. New constraints have been defined for optic pathways and brainstem to improve target coverage with no expected increase in tissue complications.

Seiten (von - bis)227-233
FachzeitschriftRadiotherapy and Oncology
PublikationsstatusVeröffentlicht - Dez. 2019
Extern publiziertJa

ASJC Scopus Sachgebiete

  • Hämatologie
  • Onkologie
  • Radiologie, Nuklearmedizin und Bildgebung


Untersuchen Sie die Forschungsthemen von „RBE-weighted dose in carbon ion therapy for ACC patients: Impact of the RBE model translation on treatment outcomes“. Zusammen bilden sie einen einzigartigen Fingerprint.

Dieses zitieren