Contents lists available at ScienceDirect Oral Oncology journal homepage: www.elsevier.com/locate/oraloncology Multi-modality 3D mandibular resection planning in head and neck cancer using CT and MRI data fusion: A clinical series J. Kraeima a, ⁎ , B. Dorgelo b , H.A. Gulbitti a , R.J.H.M. Steenbakkers c , K.P. Schepman a , J.L.N. Roodenburg a , F.K.L. Spijkervet a , R.H. Schepers a , M.J.H. Witjes a a Department of Oral and Maxillofacial Surgery, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB Groningen, The Netherlands b Department of Radiology, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB Groningen, The Netherlands c Department of Radiation Oncology, University of Groningen, University Medical Centre Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB Groningen, The Netherlands ARTICLE INFO Keywords: 3D planning VSP Data fusion Oncologic margins Accuracy Tumour visualisation MRI scan 3D imaging computer generated 3D image ABSTRACT Objectives: 3D virtual surgical planning (VSP) and guided surgery has been proven to be an effective tool for resection and reconstruction of the mandible. Currently, most widely used 3D VSP approaches to mandibular resection do not include detailed tumour information in the VSP. This manuscript presents a strategy where the aim was to incorporate tumour visualisation into the 3D virtual plan. Three-dimensional VSP of the mandibular resections was based on the fusion of CT and MRI data which was subsequently applied in clinical practice. Methods: All patients diagnosed with oral squamous cell carcinoma between 2014 and 2017 at the University Medical Centre Groningen were included. The tumour was delineated on the MRI data, after which this dataset was fused with the CT bone data in order to construct a 3D bone and tumour model for virtual resection planning. Guided resections were performed and post-operative evaluation quantified the accuracy of the re- section. The histopathological findings and patient and tumour characteristics were compared to those of a historical cohort (2009–2014) of conventional mandibular continuity resections. Results: Twenty-four patients were included in the cohort. The average deviation from planned resection was found to be 2.2 mm. Histopathologic analysis confirmed all resection planes (bone) were tumour free, compared to 96.4% in the historic cohort. Conclusion: MRI-CT base tumour visualisation and 3D resection planning is a safe and accurate method for oncologic resection of the mandible. It is an improvement on the current methods reported for 3D resection planning based solely on CT data. Introduction Surgical removal of squamous cell carcinomas in the oral cavity close to mandibular bone, often necessitates a resection of the mand- ible. A microscopic free margin of at least 5 mm on both sides of the resection is required according to clinical guidelines [1]. The oncologic- surgical challenge is to perform an adequate resection with sufficient margin, based on the pre-operative information. A widely used strategy for resection of mandibular malignancies includes the use of 3D VSP and guided surgery techniques based on computed tomography (CT) data. Both intra-operative navigation and 3D printed surgical guides have been proven to provide precise trans- lation of the 3D VSP to the surgical procedure [2–5]. Once a 3D VSP is prepared, especially when 3D printed guides [6] are applied, it assures very accurate translation of that plan to the actual procedure. However, despite accurate translation of the VSP, it is not always clear where to plan the resection margins on the mandible necessitating intraoperative exploration leading to uncertainty for both the surgeon and patients or unnecessary wide resections. The planning for adequate tumour removal should include detailed bone information as well as other tumour characteristics such as loca- lisation, size, shape and extension [7]. It is best to extract this in- formation from multi-modality imaging: CT and magnetic resonance imaging (MRI) together because the individual information is not en- ough [8]. It is reported that already a fusion 2D information of both modalities combines the sensitivities of CT and MRI, thereby proving https://doi.org/10.1016/j.oraloncology.2018.03.013 Received 22 November 2017; Received in revised form 8 March 2018; Accepted 23 March 2018 ⁎ Corresponding author. E-mail addresses: j.kraeima@umcg.nl (J. Kraeima), b.dorgelo@umcg.nl (B. Dorgelo), h.a.gulbitti@umcg.nl (H.A. Gulbitti), r.steenbakkers@umcg.nl (R.J.H.M. Steenbakkers), k.p.schepman@umcg.nl (K.P. Schepman), j.l.n.roodenburg@umcg.nl (J.L.N. Roodenburg), f.k.l.spijkervet@umcg.nl (F.K.L. Spijkervet), r.h.schepers@umcg.nl (R.H. Schepers), m.j.h.witjes@umcg.nl (M.J.H. Witjes). Oral Oncology 81 (2018) 22–28 1368-8375/ © 2018 Elsevier Ltd. All rights reserved. T