Journal of Pediatric Surgery (2013) 48, 2479–2483
www.elsevier.com/locate/jpedsurg
An augmented reality navigation system for pediatric oncologic surgery based on preoperative CT and MRI images Ryota Souzaki a,b,⁎, Satoshi Ieiri b , Munenori Uemura b , Kenoki Ohuchida b , Morimasa Tomikawa b , Yoshiaki Kinoshita a , Yuhki Koga c , Aiko Suminoe c , Kenichi Kohashi d , Yoshinao Oda d , Toshiro Hara c , Makoto Hashizume b , Tomoaki Taguchi a a
Department of Pediatric Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Department of Advance Medicine and Innovative Technology, Kyushu University Hospital, Fukuoka, Japan c Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan d Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan b
Received 25 August 2013; accepted 26 August 2013
Key words: Laparoscopic surgery; Image-guided surgery; Augmented reality
Abstract Purpose: In pediatric endoscopic surgery, a limited view and lack of tactile sensation restrict the surgeon's abilities. Moreover, in pediatric oncology, it is sometimes difficult to detect and resect tumors due to the adhesion and degeneration of tumors treated with multimodality therapies. We developed an augmented reality (AR) navigation system based on preoperative CT and MRI imaging for use in endoscopic surgery for pediatric tumors. Methods: The patients preoperatively underwent either CT or MRI with body surface markers. We used an optical tracking system to register the reconstructed 3D images obtained from the CT and MRI data and body surface markers during surgery. AR visualization was superimposed with the 3D images projected onto captured live images. Six patients underwent surgery using this system. Results: The median age of the patients was 3.5 years. Two of the six patients underwent laparoscopic surgery, two patients underwent thoracoscopic surgery, and two patients underwent laparotomy using this system. The indications for surgery were local recurrence of a Wilms tumor in one case, metastasis of rhabdomyosarcoma in one case, undifferentiated sarcoma in one case, bronchogenic cysts in two cases, and hepatoblastoma in one case. The average tumor size was 22.0 ± 14.2 mm. Four patients were treated with chemotherapy, three patients were treated with radiotherapy before surgery, and four patients underwent reoperation. All six tumors were detected using the AR navigation system and successfully resected without any complications. Conclusions: The AR navigation system is very useful for detecting the tumor location during pediatric surgery, especially for endoscopic surgery. Crown Copyright © 2013 Published by Elsevier Inc. All rights reserved.
⁎ Corresponding author. Department of Pediatric Surgery Graduate School of Medical Sciences Kyushu University 3-1-1 Maidashi, Higashi-ku Fukuoka 812–8582, Japan. Tel.: + 81 92 642 5573; fax: +81 92 642 5580. E-mail address: [email protected] (R. Souzaki). 0022-3468/$ – see front matter. Crown Copyright © 2013 Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jpedsurg.2013.08.025
2480
R. Souzaki et al.
1. Introduction
2. Materials and methods
Computed tomography (CT), ultrasound (US) and magnetic resonance imaging (MRI) have increased the amount of anatomical information available to the surgeon. Using realtime navigation based on these imaging modalities, surgeons can easily approach and visualize hidden tumors concealed by organs and detect hidden organs and vessels located under fat tissue [1–5]. We previously developed a navigation system for use in laparoscopic splenectomy in children that can present real-time anatomical information of the splenic artery and vein, which cannot be otherwise visualized without accurate navigation during surgery [5]. Recently, the use of laparoscopic resection to treat pediatric malignant tumors, such as neuroblastomas, was reported in the literature [6, 7]. However, some surgeries for pediatric oncologic tumors are performed as reoperations after biopsies, chemotherapy and radiotherapy. Therefore, it is sometimes difficult to detect and resect tumors due to adhesion to the surrounding organs caused by previous surgeries and the effects of preoperative chemotherapy and radiotherapy, which decrease the tumor size. Moreover, the difficulty of performing surgery using endoscopic procedures in these cases is increased due to limited views and a lack of tactile sensation. Therefore, we believe that pediatric oncologic surgery is a good indication for surgery using real-time navigation. We developed an augmented reality (AR) navigation system based on preoperative CT and MRI imaging for endoscopic surgery and laparotomy and herein report our experience with this navigation system in endoscopic surgery and laparotomy for pediatric tumors.
As reported previously, we have performed navigation surgery for laparoscopic splenectomy in children [5]. Our navigation system provides real-time anatomical information of the pancreas and splenic artery and vein and is very useful and accurate. We employed this navigation system in pediatric surgery for tumors and constructed an AR visualization system that superimposed preoperative MDCT (multi-detector computed tomography) and MRI images onto captured laparoscopic and video camera live images. In this process, multimodality markers (Chiyoda Technol, Tokyo, Japan) are initially fixed to the patient's body surface during MDCT or MRI. Using the DICOM data obtained from MDCT and MRI, volume images are reconstructed using a 3D viewer software program (Virtual Place 300, AZE Co Ltd., Tokyo, Japan). The tumor is extracted and segmentation is performed. The multimodality markers are fixed to the patient's body surface in the same locations during surgery. The coordinates of each marker are obtained with an optical tracking device (Polaris, Northern Digital Inc., Ontario, Canada) during surgery. Registration is performed between each marker point on the body and 3D images are reconstructed. A rigid body with optical markers is attached to a scope for endoscopic surgery or a video camera for open surgery to measure the six degrees of freedom pose parameters using the optical tracker, and a rotary encoder is attached to the scope cylinder to measure the rotation parameters. Afterwards, the directions of the laparoscopic or video camera views are calculated. Using the measurements of the rotation
Fig. 1 A: An overlay image of AR navigation obtained during laparoscopic surgery in Case 1. We were unable to detect the tumor location using endoscopic images alone. The black arrow indicates a 3D image of the tumor projected onto captured endoscopic live images or video camera live images. The gray arrow indicates adhesion. B: A computed tomography (CT) scan showing an 8-mm mass in the left side of the chest wall.
live live dead live live live No No No No No No location location location location location surgical border Yes Yes Yes No No No
91 119 212 59 303 291
8 6 21 20 37 40
3. Results
Yes Yes Yes No No Yes TS: thoracoscopic surgery, LS: laparoscopic surgery, LA: laparotomy.
8 4 2 3 12 1
2481 parameters of the scope or camera, the navigation images can be made to correspond to changes in the field of view. In this way, the AR visualization is superimposed with the preoperative 3D images projected onto captured endoscopic live images or video camera live images. This study was conducted according to the ethical guidelines of clinical research issued by the Ministry of Health, Labour and Welfare. Signed informed consent was obtained from the parents of all of the patients (representative institutional review board approval no. 22047, Kyushu University Graduate School of Medical Sciences).
Yes Yes Yes Yes No No TS (extirpation) LS (extirpation) LA (extirpation) TS (extirpation) LS (extirpation) LA (right lobectomy) 1 2 3 4 5 6
recurrence of rhabdomyosarcoma local recurrence of Wilms’ tumor undifferentiated sarcoma bronchogenic cyst (mediastinum) bronchogenic cyst (stomach) hepatoblastoma
Operative procedure Patient Age(year) Diagnosis
Table 1
Patients for navigation surgery.
Re-operation Preoperative Preoperative Operation Size Object of chemotherapy radiotherapy time (min) (mm) navigation
Complication Prognosis
Augmented reality navigation system for oncologic surgery
The overlay images of AR navigation obtained during laparoscopic surgery in Case 1 are shown in Fig. 1A. This patient was diagnosed with alveolar rhabdomyosarcoma in the soft plate at 5 years of age. At 6 years of age, a metastatic tumor was recognized in the left chest wall and was resected using thoracoscopy. After surgery, the patient was treated with postoperative chemotherapy and radiotherapy. At 8 years of age, a tiny recurrent mass was detected in the left chest wall on a CT scan. Identifying and resecting the tumor using thoracoscopic surgery were considered difficult because the tumor was small (8 mm) (Fig. 1B) and pleural adhesion was expected. Therefore, we used the AR navigation system. Indeed, there was pleural adhesion and the tumor was not a bump. Although we were unable to detect the tumor on endoscopic images alone, we were able to resect the tumor based on navigation images. Navigation surgery for pediatric tumors were performed in six patients. The clinical data of the patients treated with this navigation system are shown in Table 1. The median age of the patients was 3.5 years (1–12 years). Two of the six patients underwent laparoscopic surgery, two patients underwent thoracoscopic surgery and two patients underwent laparotomy. The indications for surgery were local recurrence of a Wilms tumor in one case, metastasis of rhabdomyosarcoma in the chest wall in one case, undifferentiated sarcoma of the pelvis in one case, a bronchogenic cyst of the mediastinum in one case, a bronchogenic cyst of the stomach in one case and hepatoblastoma in one case. Concerning the objectives of navigation surgery, five of the six patients underwent surgery to detect the tumor location, while the remaining patient with hepatoblastoma underwent surgery to confirm the tumor margins for right lobectomy of the liver (Fig. 2A, B). The average tumor size was 22.0 ± 14.2 mm (6 ~ 40 mm). Three malignant tumors were treated with chemotherapy and radiotherapy before surgery. Four of the six operations were reoperations, and we were able to remove the tumors with minimum adhesiotomy using the navigation system. The pathological findings showed that all six cases were resected completely. Although one patient died due to the side effects of
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Fig. 2 A: A video camera capturing live images for navigation. B: An overlay image of AR navigation obtained during surgery in Case 6. AR navigation revealed the tumor in the liver and we confirmed the tumor margins during right lobectomy of the liver.
postoperative chemotherapy, all six tumors were detected using the AR navigation system and successfully resected without any complications.
4. Discussion We performed tumor resection using the AR navigation system in children. This system is very useful for performing resection of pediatric tumors because pediatric patients with tumors are sometimes treated with chemotherapy and radiotherapy and have undergone previous surgeries. Adhesion and degenerated tissue caused by previous surgeries, chemotherapy and radiotherapy can disturb future surgeries, especially endoscopic surgery. In this study, the navigation system allowed us to detect and resect the tumors with minimum adhesiotomy without any difficulties. We previously reported that the accuracy of our navigation system for superimposing images is sufficient and acceptable to enable surgeons to detect the precise 3D orientation. The target registration error (TRE), which indicates the distance from the target to the reconstructed 3D volume data, was 5.03 ± 1.57 mm in a previous study [5]. In the current cases, we were unable to calculate the TRE because, in some cases, the tumor location could not be detected without navigation. However, this system is acceptable for detecting tumors using endoscopic surgery because the pathological findings showed that complete resection was achieved in all cases. Concerning navigation surgery for pediatric malignancies, Ueno S et al. [8]. reported the use of a navigation system in a metastatic neuroblastoma patient. However, that navigation system was used to perform a bone marrow biopsy with real-time MRI. We reported the use of a realtime surgical navigation system in which the pointer of the surgical field was displayed on the 3D image reconstructed from an MRI image (Case 3) [9]. Our previous navigation
system did not use live images obtained with a scope or camera. To our knowledge, this is the first report of the induction of a full-fledged intraoperative AR navigation system in pediatric endoscopic surgery for tumors. The pediatric oncologic surgery was required to be a less invasive and safe procedure because surgical complications and invasive surgery can delay the administration of postoperative chemotherapy. We believed that this kind of imageguided navigation surgery would be most effective for use in pediatric endoscopic surgery for malignancy. There is a problem associated with the navigation system during surgery, especially endoscopic surgery, with respect to motion and deformation of the intraoperative images of organs. Respiratory movement and deformation caused by pressure from the pneumoperitoneum are important factors that create differences between the images and reality. Moreover, we used this navigation system for hepatoblastoma and detected the location of the tumor before resection. However, the navigation system was not able to be used for tumour detection with liver resection due to intra operative organ movement. Because navigation system data are based on preoperative imaging of the previous day, it can't follow the intra-operative organ deformations. The accuracy of our navigation system is acceptable; however, we will attempt to increase the accuracy of our present system, especially for endoscopic surgery, using new modalities, such as open MRI, to capture intraoperative organ deformation.
5. Conclusion The AR navigation system is therefore considered to be very useful and good method for detecting the unrecognized tumor location during pediatric surgery, especially for endoscopic surgery.
Augmented reality navigation system for oncologic surgery
References [1] Konishi K, Nakamoto M, Kakeji Y, et al. A real-time navigation system for laparoscopic surgery based on three-dimensional ultrasound using magneto-optic hybrid tracking configuration. Int J CARS 2007;2:1-10. [2] Hong J, Nakashima H, Konishi K, et al. Interventional navigation for abdominal therapy based on simultaneous use of MRI and ultrasound. Med Biol Eng Comput 2006;44:1127-34. [3] Hong J, Matsumoto N, Ouchida R, et al. Medical navigation system for otologic surgery based on hybrid registration and virtual intraoperative computed tomography. IEEE Trans Biomed Eng 2009;56:2. [4] Maeda T, Hong J, Konishi K, et al. Tumor ablation therapy of liver cancers with an open magnetic resonance imaging-based navigation system. Surg Endosc 2009;23:1048-53.
2483 [5] Ieiri S, Uemura M, Konishi K, et al. Augmented reality navigation system for laparoscopic splenectomy in children based on preoperative CT image using optical tracking device. Pediatr Surg Int 2012;28:341-6. [6] St Peter SD, Valusek PA, Hill S, et al. Laparoscopic adrenalectomy in children: a multicenter experience. J Laparoendosc Adv Surg Tech A 2011;21:647-9. [7] Iwanaka T, Arai M, Ito M, et al. Challenges of laparoscopic resection of abdominal neuroblastoma with lymphadenectomy. A preliminary report. Surg Endosc 2001;15:489-92. [8] Ueno S, Yokoyama S, Hirakawa H, et al. Use of real-time magnetic resonance guidance to assist bone biopsy in pediatric malignancy. Pediatrics 2002;109:E18. [9] Souzaki R, Kinoshita Y, Matsuura T, et al. Successful resection of an undifferentiated sarcoma in a child using a real-time surgical navigation system in an open magnetic resonance imaging operation room. J Pediatr Surg 2011;46:608-11.
www.elsevier.com/locate/jpedsurg
An augmented reality navigation system for pediatric oncologic surgery based on preoperative CT and MRI images Ryota Souzaki a,b,⁎, Satoshi Ieiri b , Munenori Uemura b , Kenoki Ohuchida b , Morimasa Tomikawa b , Yoshiaki Kinoshita a , Yuhki Koga c , Aiko Suminoe c , Kenichi Kohashi d , Yoshinao Oda d , Toshiro Hara c , Makoto Hashizume b , Tomoaki Taguchi a a
Department of Pediatric Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Department of Advance Medicine and Innovative Technology, Kyushu University Hospital, Fukuoka, Japan c Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan d Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan b
Received 25 August 2013; accepted 26 August 2013
Key words: Laparoscopic surgery; Image-guided surgery; Augmented reality
Abstract Purpose: In pediatric endoscopic surgery, a limited view and lack of tactile sensation restrict the surgeon's abilities. Moreover, in pediatric oncology, it is sometimes difficult to detect and resect tumors due to the adhesion and degeneration of tumors treated with multimodality therapies. We developed an augmented reality (AR) navigation system based on preoperative CT and MRI imaging for use in endoscopic surgery for pediatric tumors. Methods: The patients preoperatively underwent either CT or MRI with body surface markers. We used an optical tracking system to register the reconstructed 3D images obtained from the CT and MRI data and body surface markers during surgery. AR visualization was superimposed with the 3D images projected onto captured live images. Six patients underwent surgery using this system. Results: The median age of the patients was 3.5 years. Two of the six patients underwent laparoscopic surgery, two patients underwent thoracoscopic surgery, and two patients underwent laparotomy using this system. The indications for surgery were local recurrence of a Wilms tumor in one case, metastasis of rhabdomyosarcoma in one case, undifferentiated sarcoma in one case, bronchogenic cysts in two cases, and hepatoblastoma in one case. The average tumor size was 22.0 ± 14.2 mm. Four patients were treated with chemotherapy, three patients were treated with radiotherapy before surgery, and four patients underwent reoperation. All six tumors were detected using the AR navigation system and successfully resected without any complications. Conclusions: The AR navigation system is very useful for detecting the tumor location during pediatric surgery, especially for endoscopic surgery. Crown Copyright © 2013 Published by Elsevier Inc. All rights reserved.
⁎ Corresponding author. Department of Pediatric Surgery Graduate School of Medical Sciences Kyushu University 3-1-1 Maidashi, Higashi-ku Fukuoka 812–8582, Japan. Tel.: + 81 92 642 5573; fax: +81 92 642 5580. E-mail address: [email protected] (R. Souzaki). 0022-3468/$ – see front matter. Crown Copyright © 2013 Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jpedsurg.2013.08.025
2480
R. Souzaki et al.
1. Introduction
2. Materials and methods
Computed tomography (CT), ultrasound (US) and magnetic resonance imaging (MRI) have increased the amount of anatomical information available to the surgeon. Using realtime navigation based on these imaging modalities, surgeons can easily approach and visualize hidden tumors concealed by organs and detect hidden organs and vessels located under fat tissue [1–5]. We previously developed a navigation system for use in laparoscopic splenectomy in children that can present real-time anatomical information of the splenic artery and vein, which cannot be otherwise visualized without accurate navigation during surgery [5]. Recently, the use of laparoscopic resection to treat pediatric malignant tumors, such as neuroblastomas, was reported in the literature [6, 7]. However, some surgeries for pediatric oncologic tumors are performed as reoperations after biopsies, chemotherapy and radiotherapy. Therefore, it is sometimes difficult to detect and resect tumors due to adhesion to the surrounding organs caused by previous surgeries and the effects of preoperative chemotherapy and radiotherapy, which decrease the tumor size. Moreover, the difficulty of performing surgery using endoscopic procedures in these cases is increased due to limited views and a lack of tactile sensation. Therefore, we believe that pediatric oncologic surgery is a good indication for surgery using real-time navigation. We developed an augmented reality (AR) navigation system based on preoperative CT and MRI imaging for endoscopic surgery and laparotomy and herein report our experience with this navigation system in endoscopic surgery and laparotomy for pediatric tumors.
As reported previously, we have performed navigation surgery for laparoscopic splenectomy in children [5]. Our navigation system provides real-time anatomical information of the pancreas and splenic artery and vein and is very useful and accurate. We employed this navigation system in pediatric surgery for tumors and constructed an AR visualization system that superimposed preoperative MDCT (multi-detector computed tomography) and MRI images onto captured laparoscopic and video camera live images. In this process, multimodality markers (Chiyoda Technol, Tokyo, Japan) are initially fixed to the patient's body surface during MDCT or MRI. Using the DICOM data obtained from MDCT and MRI, volume images are reconstructed using a 3D viewer software program (Virtual Place 300, AZE Co Ltd., Tokyo, Japan). The tumor is extracted and segmentation is performed. The multimodality markers are fixed to the patient's body surface in the same locations during surgery. The coordinates of each marker are obtained with an optical tracking device (Polaris, Northern Digital Inc., Ontario, Canada) during surgery. Registration is performed between each marker point on the body and 3D images are reconstructed. A rigid body with optical markers is attached to a scope for endoscopic surgery or a video camera for open surgery to measure the six degrees of freedom pose parameters using the optical tracker, and a rotary encoder is attached to the scope cylinder to measure the rotation parameters. Afterwards, the directions of the laparoscopic or video camera views are calculated. Using the measurements of the rotation
Fig. 1 A: An overlay image of AR navigation obtained during laparoscopic surgery in Case 1. We were unable to detect the tumor location using endoscopic images alone. The black arrow indicates a 3D image of the tumor projected onto captured endoscopic live images or video camera live images. The gray arrow indicates adhesion. B: A computed tomography (CT) scan showing an 8-mm mass in the left side of the chest wall.
live live dead live live live No No No No No No location location location location location surgical border Yes Yes Yes No No No
91 119 212 59 303 291
8 6 21 20 37 40
3. Results
Yes Yes Yes No No Yes TS: thoracoscopic surgery, LS: laparoscopic surgery, LA: laparotomy.
8 4 2 3 12 1
2481 parameters of the scope or camera, the navigation images can be made to correspond to changes in the field of view. In this way, the AR visualization is superimposed with the preoperative 3D images projected onto captured endoscopic live images or video camera live images. This study was conducted according to the ethical guidelines of clinical research issued by the Ministry of Health, Labour and Welfare. Signed informed consent was obtained from the parents of all of the patients (representative institutional review board approval no. 22047, Kyushu University Graduate School of Medical Sciences).
Yes Yes Yes Yes No No TS (extirpation) LS (extirpation) LA (extirpation) TS (extirpation) LS (extirpation) LA (right lobectomy) 1 2 3 4 5 6
recurrence of rhabdomyosarcoma local recurrence of Wilms’ tumor undifferentiated sarcoma bronchogenic cyst (mediastinum) bronchogenic cyst (stomach) hepatoblastoma
Operative procedure Patient Age(year) Diagnosis
Table 1
Patients for navigation surgery.
Re-operation Preoperative Preoperative Operation Size Object of chemotherapy radiotherapy time (min) (mm) navigation
Complication Prognosis
Augmented reality navigation system for oncologic surgery
The overlay images of AR navigation obtained during laparoscopic surgery in Case 1 are shown in Fig. 1A. This patient was diagnosed with alveolar rhabdomyosarcoma in the soft plate at 5 years of age. At 6 years of age, a metastatic tumor was recognized in the left chest wall and was resected using thoracoscopy. After surgery, the patient was treated with postoperative chemotherapy and radiotherapy. At 8 years of age, a tiny recurrent mass was detected in the left chest wall on a CT scan. Identifying and resecting the tumor using thoracoscopic surgery were considered difficult because the tumor was small (8 mm) (Fig. 1B) and pleural adhesion was expected. Therefore, we used the AR navigation system. Indeed, there was pleural adhesion and the tumor was not a bump. Although we were unable to detect the tumor on endoscopic images alone, we were able to resect the tumor based on navigation images. Navigation surgery for pediatric tumors were performed in six patients. The clinical data of the patients treated with this navigation system are shown in Table 1. The median age of the patients was 3.5 years (1–12 years). Two of the six patients underwent laparoscopic surgery, two patients underwent thoracoscopic surgery and two patients underwent laparotomy. The indications for surgery were local recurrence of a Wilms tumor in one case, metastasis of rhabdomyosarcoma in the chest wall in one case, undifferentiated sarcoma of the pelvis in one case, a bronchogenic cyst of the mediastinum in one case, a bronchogenic cyst of the stomach in one case and hepatoblastoma in one case. Concerning the objectives of navigation surgery, five of the six patients underwent surgery to detect the tumor location, while the remaining patient with hepatoblastoma underwent surgery to confirm the tumor margins for right lobectomy of the liver (Fig. 2A, B). The average tumor size was 22.0 ± 14.2 mm (6 ~ 40 mm). Three malignant tumors were treated with chemotherapy and radiotherapy before surgery. Four of the six operations were reoperations, and we were able to remove the tumors with minimum adhesiotomy using the navigation system. The pathological findings showed that all six cases were resected completely. Although one patient died due to the side effects of
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Fig. 2 A: A video camera capturing live images for navigation. B: An overlay image of AR navigation obtained during surgery in Case 6. AR navigation revealed the tumor in the liver and we confirmed the tumor margins during right lobectomy of the liver.
postoperative chemotherapy, all six tumors were detected using the AR navigation system and successfully resected without any complications.
4. Discussion We performed tumor resection using the AR navigation system in children. This system is very useful for performing resection of pediatric tumors because pediatric patients with tumors are sometimes treated with chemotherapy and radiotherapy and have undergone previous surgeries. Adhesion and degenerated tissue caused by previous surgeries, chemotherapy and radiotherapy can disturb future surgeries, especially endoscopic surgery. In this study, the navigation system allowed us to detect and resect the tumors with minimum adhesiotomy without any difficulties. We previously reported that the accuracy of our navigation system for superimposing images is sufficient and acceptable to enable surgeons to detect the precise 3D orientation. The target registration error (TRE), which indicates the distance from the target to the reconstructed 3D volume data, was 5.03 ± 1.57 mm in a previous study [5]. In the current cases, we were unable to calculate the TRE because, in some cases, the tumor location could not be detected without navigation. However, this system is acceptable for detecting tumors using endoscopic surgery because the pathological findings showed that complete resection was achieved in all cases. Concerning navigation surgery for pediatric malignancies, Ueno S et al. [8]. reported the use of a navigation system in a metastatic neuroblastoma patient. However, that navigation system was used to perform a bone marrow biopsy with real-time MRI. We reported the use of a realtime surgical navigation system in which the pointer of the surgical field was displayed on the 3D image reconstructed from an MRI image (Case 3) [9]. Our previous navigation
system did not use live images obtained with a scope or camera. To our knowledge, this is the first report of the induction of a full-fledged intraoperative AR navigation system in pediatric endoscopic surgery for tumors. The pediatric oncologic surgery was required to be a less invasive and safe procedure because surgical complications and invasive surgery can delay the administration of postoperative chemotherapy. We believed that this kind of imageguided navigation surgery would be most effective for use in pediatric endoscopic surgery for malignancy. There is a problem associated with the navigation system during surgery, especially endoscopic surgery, with respect to motion and deformation of the intraoperative images of organs. Respiratory movement and deformation caused by pressure from the pneumoperitoneum are important factors that create differences between the images and reality. Moreover, we used this navigation system for hepatoblastoma and detected the location of the tumor before resection. However, the navigation system was not able to be used for tumour detection with liver resection due to intra operative organ movement. Because navigation system data are based on preoperative imaging of the previous day, it can't follow the intra-operative organ deformations. The accuracy of our navigation system is acceptable; however, we will attempt to increase the accuracy of our present system, especially for endoscopic surgery, using new modalities, such as open MRI, to capture intraoperative organ deformation.
5. Conclusion The AR navigation system is therefore considered to be very useful and good method for detecting the unrecognized tumor location during pediatric surgery, especially for endoscopic surgery.
Augmented reality navigation system for oncologic surgery
References [1] Konishi K, Nakamoto M, Kakeji Y, et al. A real-time navigation system for laparoscopic surgery based on three-dimensional ultrasound using magneto-optic hybrid tracking configuration. Int J CARS 2007;2:1-10. [2] Hong J, Nakashima H, Konishi K, et al. Interventional navigation for abdominal therapy based on simultaneous use of MRI and ultrasound. Med Biol Eng Comput 2006;44:1127-34. [3] Hong J, Matsumoto N, Ouchida R, et al. Medical navigation system for otologic surgery based on hybrid registration and virtual intraoperative computed tomography. IEEE Trans Biomed Eng 2009;56:2. [4] Maeda T, Hong J, Konishi K, et al. Tumor ablation therapy of liver cancers with an open magnetic resonance imaging-based navigation system. Surg Endosc 2009;23:1048-53.
2483 [5] Ieiri S, Uemura M, Konishi K, et al. Augmented reality navigation system for laparoscopic splenectomy in children based on preoperative CT image using optical tracking device. Pediatr Surg Int 2012;28:341-6. [6] St Peter SD, Valusek PA, Hill S, et al. Laparoscopic adrenalectomy in children: a multicenter experience. J Laparoendosc Adv Surg Tech A 2011;21:647-9. [7] Iwanaka T, Arai M, Ito M, et al. Challenges of laparoscopic resection of abdominal neuroblastoma with lymphadenectomy. A preliminary report. Surg Endosc 2001;15:489-92. [8] Ueno S, Yokoyama S, Hirakawa H, et al. Use of real-time magnetic resonance guidance to assist bone biopsy in pediatric malignancy. Pediatrics 2002;109:E18. [9] Souzaki R, Kinoshita Y, Matsuura T, et al. Successful resection of an undifferentiated sarcoma in a child using a real-time surgical navigation system in an open magnetic resonance imaging operation room. J Pediatr Surg 2011;46:608-11.
