Transcript
Thank you, President and Chair, for giving me this opportunity. Sorry. Today, I would like to talk about the Availability and the Validity of Multi-Image Fusion Technique for Dose Planning. This paper is cooperated by our department of radio-oncology and department of radiology.
This is a picture. When I [inaudible 00:00:34.290] to run the Novalis, I was given this picture maybe from Professor [inaudible 00:00:42.408]. And I was very impressed with this picture because this picture expected the potential ability for less invasive radiosurgery or treatment. So, for this aim, for less invasive stereotactic radiation therapy, we think it is very important to make precise and delicate dose planning. So, we study the availability of the effectiveness of the application of the functional image including FDG-PET and tractography for less invasive dose planning.
Clinical materials and method. We have treated over 240 intracranial lesions with Novalis in these 2 years. The image fusion of CT and MRI is performed routinely. And FDG-PET was applicated for recurrent cases, skull base lesions, and some complicated lesion. Facial nerve tractography was applied for vestibular schwannoma cases. Venography was applied for lesions beside bridging veins.
The protocol of MRI. This slide shows the protocol of MRI, and this is tensor imaging. We use the ordinary 1.5 Tesla MRI unit, like this from the Siemens. The DTI, the protocol of DTI like this.
About the FDG-PET, we use the apparatus SET-3000G produced by Shimadzu, made in Japan. The protocol was as follows, like this, administration of FDG, 5 micro Curie, and waiting time, 50 minutes, scanning time, 10 minutes, parameter, AFOV300, imaging, DRAMA 64, slice thickness is 2.9 millimeter, not so precise.
Here, I will show you the representative cases. This is Case 1. This patient has a metastatic lesion here previously. Previously, Gamma Knife was applied for this region. And the follow-up MRI shows the enhanced lesion here. We are very puzzled of this recurrence of brain necrosis. So we apply the PET. The PET shows the hotspot. So we diagnose the recurrence. However, in the same case, in the same case, the patient has a small lesion here, like this, but unfortunately, this lesion could not be detected by FDG-PET. This is the limitation of PET.
Case 2, 19 years old male. The diagnosis is germinoma. He developed a morning headache at 12 years old and was diagnosed as pineal tumor with hydrocephalus. He underwent extirpation of the tumor, chemotherapy, and local radiation therapy, 24 Gy. About this radiation therapy, we are very grateful. We should perform the whole-ventricular radiation for this patient with the [inaudible 00:04:52.975]. Then he underwent radiation therapy and chemotherapy repeatedly, three times. This is a follow-up MRI. You see, you know, here is the lesion. And we applied the FDG-PET at just the hot region. So we diagnose, this is the recurrence, so SRS by Novalis was performed and the lesion was vanished four months later, here. In the same case and in the same time MRI another region of the brain here where you see the enhanced area here in the left frontal lobe. But the FDG-PET shows the cold spot, cold area. So this is radiation necrosis.
Case 3. Now, this is the case of adenocystic carcinoma. The tumor invades the skull base externally [SP], but in this area, it's very opaque. So PET shows the tumor invaded to around the right orbita. So we make a dose planning including this area. And this is our...dose planning, like this. And we did SRT by IMRT technique. And the post-irradiation, fortunately, the tumor shrunk two months later. A very good case.
And another technique is DTI. Various tractographies were tried to make a dose planning. In our department, of course, I'm neurosurgeon. We use the pyramidal tractography, or optical tractography, or facial nerve tractography for our surgery. Here, I will present our facial nerve tractography because that is maybe useful for vestibular schwannoma cases. This is a protocol of facial nerve tractography. We use ordinary 1.5 MR unit, and diffusion tensor imaging parameter like this. And the diffusion tensor calculation was performed with this software.
I show our technique here. This technique developed by our department. At first, various tracts were randomly described between meatus and cerebellopontine angle with FA threshold 0.1, like this. And reformat and to make sagittal images. And here is the meatus. And as you know, the facial nerve located here in the meatus. Facial nerve, cochlear nerve, and upper vestibular nerve, lower vestibular nerve, like this. And we put the seal [SP] here, and then to make tractography. And we adjust the FA threshold between 0.1 and 0.2. And finally, to make like this, you see. Here is the facial nerve. This is a vestibular tumor. You see. The facial nerve and the vestibular tumor. And for surgery, we transferred this data to the iPlan by BrainLab for vector vision. And this is our surgery. And you see, during the surgery, we inspect the accuracy of the facial nerve tractography. You know, you see, we point out the facial nerve by neuronavigation. And we give some electrical stimulation and check the facial nerve response. And we confirmed the accuracy of the facial nerve tractography. I think tractography is virtual, so it is very important to inspect the accuracy.
This is a case for the radiation therapy. You see, here's the vestibular schwannoma and the facial nerve tractography shows the facial nerve like this. This is the dose planning. Here is the facial nerve. Unfortunately, our BrainSCAN don't accept the tractography, only iPlan. So we make the approximate planning on iPlanning and manually we translate the facial nerve tract like this.
Finally, I show you the representative cases. For us neurosurgeon, it is very important to preserve the bridging vein. This is that representative case. This 69 F, the left falx meningioma. The deviated superior sagittal sinus was injured during the operation. The right after the operation CT revealed uneventful findings, however, the patient developed psychiatric symptoms and mild aphasia a couple of days later. The following CT on Day 4 demonstrated venous infarction with hemorrhage in the left frontal lobe. A postoperative angiogram, this is the postoperative angiogram, shows occlusion of the SSS, partial occlusion. We conservatively treated with depressants for cerebrospinal pressure, steroidal and glycerol, and the symptom disappeared two weeks thereafter. Of course, for about the irradiation, we should avoid to irradiate these structure.
So, we devise... So, for that aim, we use the CT venography. This is a CT venography, SSS and bridging veins, and the parameter to take this picture like this. Contrast medium was administered intravenously. Total amount 100 milliliter, rate 4 milliliter/second, scan timing, the scan starts 5 seconds later after the CE concentration in the carotid artery exceeds 100HU. I fuse such venography information and MRI information. This is a small metastatic lesion close to the transverse sinus, you see, and make dose planning like this. We avoid the bridging vein and transverse sinus, you see. Here is the lesion. This is the sinus.
In my conclusion, the fusion of PET is useful for determination of the GTV/PTV, namely, distinguish recurrence from necrosis, however, the space resolution is not acceptable for precise dose planning. The fusion of the tractography is a promising method for avoiding the radiation injury of eloquent structure, however, that is a virtual neural pathway, therefore the inspection of the reliability or accuracy is indispensable. The influence on the bridging vein should be considered for less invasive radiotherapy. Thank you for your attention.
This is a picture. When I [inaudible 00:00:34.290] to run the Novalis, I was given this picture maybe from Professor [inaudible 00:00:42.408]. And I was very impressed with this picture because this picture expected the potential ability for less invasive radiosurgery or treatment. So, for this aim, for less invasive stereotactic radiation therapy, we think it is very important to make precise and delicate dose planning. So, we study the availability of the effectiveness of the application of the functional image including FDG-PET and tractography for less invasive dose planning.
Clinical materials and method. We have treated over 240 intracranial lesions with Novalis in these 2 years. The image fusion of CT and MRI is performed routinely. And FDG-PET was applicated for recurrent cases, skull base lesions, and some complicated lesion. Facial nerve tractography was applied for vestibular schwannoma cases. Venography was applied for lesions beside bridging veins.
The protocol of MRI. This slide shows the protocol of MRI, and this is tensor imaging. We use the ordinary 1.5 Tesla MRI unit, like this from the Siemens. The DTI, the protocol of DTI like this.
About the FDG-PET, we use the apparatus SET-3000G produced by Shimadzu, made in Japan. The protocol was as follows, like this, administration of FDG, 5 micro Curie, and waiting time, 50 minutes, scanning time, 10 minutes, parameter, AFOV300, imaging, DRAMA 64, slice thickness is 2.9 millimeter, not so precise.
Here, I will show you the representative cases. This is Case 1. This patient has a metastatic lesion here previously. Previously, Gamma Knife was applied for this region. And the follow-up MRI shows the enhanced lesion here. We are very puzzled of this recurrence of brain necrosis. So we apply the PET. The PET shows the hotspot. So we diagnose the recurrence. However, in the same case, in the same case, the patient has a small lesion here, like this, but unfortunately, this lesion could not be detected by FDG-PET. This is the limitation of PET.
Case 2, 19 years old male. The diagnosis is germinoma. He developed a morning headache at 12 years old and was diagnosed as pineal tumor with hydrocephalus. He underwent extirpation of the tumor, chemotherapy, and local radiation therapy, 24 Gy. About this radiation therapy, we are very grateful. We should perform the whole-ventricular radiation for this patient with the [inaudible 00:04:52.975]. Then he underwent radiation therapy and chemotherapy repeatedly, three times. This is a follow-up MRI. You see, you know, here is the lesion. And we applied the FDG-PET at just the hot region. So we diagnose, this is the recurrence, so SRS by Novalis was performed and the lesion was vanished four months later, here. In the same case and in the same time MRI another region of the brain here where you see the enhanced area here in the left frontal lobe. But the FDG-PET shows the cold spot, cold area. So this is radiation necrosis.
Case 3. Now, this is the case of adenocystic carcinoma. The tumor invades the skull base externally [SP], but in this area, it's very opaque. So PET shows the tumor invaded to around the right orbita. So we make a dose planning including this area. And this is our...dose planning, like this. And we did SRT by IMRT technique. And the post-irradiation, fortunately, the tumor shrunk two months later. A very good case.
And another technique is DTI. Various tractographies were tried to make a dose planning. In our department, of course, I'm neurosurgeon. We use the pyramidal tractography, or optical tractography, or facial nerve tractography for our surgery. Here, I will present our facial nerve tractography because that is maybe useful for vestibular schwannoma cases. This is a protocol of facial nerve tractography. We use ordinary 1.5 MR unit, and diffusion tensor imaging parameter like this. And the diffusion tensor calculation was performed with this software.
I show our technique here. This technique developed by our department. At first, various tracts were randomly described between meatus and cerebellopontine angle with FA threshold 0.1, like this. And reformat and to make sagittal images. And here is the meatus. And as you know, the facial nerve located here in the meatus. Facial nerve, cochlear nerve, and upper vestibular nerve, lower vestibular nerve, like this. And we put the seal [SP] here, and then to make tractography. And we adjust the FA threshold between 0.1 and 0.2. And finally, to make like this, you see. Here is the facial nerve. This is a vestibular tumor. You see. The facial nerve and the vestibular tumor. And for surgery, we transferred this data to the iPlan by BrainLab for vector vision. And this is our surgery. And you see, during the surgery, we inspect the accuracy of the facial nerve tractography. You know, you see, we point out the facial nerve by neuronavigation. And we give some electrical stimulation and check the facial nerve response. And we confirmed the accuracy of the facial nerve tractography. I think tractography is virtual, so it is very important to inspect the accuracy.
This is a case for the radiation therapy. You see, here's the vestibular schwannoma and the facial nerve tractography shows the facial nerve like this. This is the dose planning. Here is the facial nerve. Unfortunately, our BrainSCAN don't accept the tractography, only iPlan. So we make the approximate planning on iPlanning and manually we translate the facial nerve tract like this.
Finally, I show you the representative cases. For us neurosurgeon, it is very important to preserve the bridging vein. This is that representative case. This 69 F, the left falx meningioma. The deviated superior sagittal sinus was injured during the operation. The right after the operation CT revealed uneventful findings, however, the patient developed psychiatric symptoms and mild aphasia a couple of days later. The following CT on Day 4 demonstrated venous infarction with hemorrhage in the left frontal lobe. A postoperative angiogram, this is the postoperative angiogram, shows occlusion of the SSS, partial occlusion. We conservatively treated with depressants for cerebrospinal pressure, steroidal and glycerol, and the symptom disappeared two weeks thereafter. Of course, for about the irradiation, we should avoid to irradiate these structure.
So, we devise... So, for that aim, we use the CT venography. This is a CT venography, SSS and bridging veins, and the parameter to take this picture like this. Contrast medium was administered intravenously. Total amount 100 milliliter, rate 4 milliliter/second, scan timing, the scan starts 5 seconds later after the CE concentration in the carotid artery exceeds 100HU. I fuse such venography information and MRI information. This is a small metastatic lesion close to the transverse sinus, you see, and make dose planning like this. We avoid the bridging vein and transverse sinus, you see. Here is the lesion. This is the sinus.
In my conclusion, the fusion of PET is useful for determination of the GTV/PTV, namely, distinguish recurrence from necrosis, however, the space resolution is not acceptable for precise dose planning. The fusion of the tractography is a promising method for avoiding the radiation injury of eloquent structure, however, that is a virtual neural pathway, therefore the inspection of the reliability or accuracy is indispensable. The influence on the bridging vein should be considered for less invasive radiotherapy. Thank you for your attention.