Transcript
Thank you very much for giving the excellent opportunity to join this virtual meeting. My paper should have been presented at the first day session but I wasn't there, so I had a, actually, double booking and I was lecture in Japan. So, let me apologize. So, I really thank the...for all staffs in the Brainlab and the chairmans for shifting my paper to today's session.
Today, I'll be talking about our initial experience of Novalis Stereotactic Radiation Therapy for Gamma-Knife-Untreatable Meningiomas. Of course, Gamma knife is a effective and very safe treatment for meningiomas. The progression for a survival at the five years mark is more than 95%. There is a tremendous achievement, I think. But the indication is somewhat limited because of some factors. So today, we review our initial experience of this treatment and clarified its effectiveness and indication.
Since we started the Novalis treatment in July 2006, we treated more than 200 cases with intracranial tumors. Among of them, 15 patient had a meningioma which are unsuitable for Gamma knife. Tumor dominantly located in a parasagittal region, going suprasella, tentrial confluens, and so on. The average tumor volume was 31 cubic centimeter, ranged up to 91 cubic centimeter. So, quite a huge tumor size group.
According to the pathology, nine patient were grade 1, three were grade 2, and one was grade 3 anaplastic meningioma. While the treatment parameters are...the average of total dose was 36.8 Gray, we must reuse 40 Gray in 10 fraction. In a half of this group, we used IMRT.
Let me go to the demonstrative case. This patient had a parasagittal meningioma, WHO grade 1. She had a recurrent of tumor despite of [inaudible 00:02:39.530] operation. The tumor size is very huge, 52.1 cubic centimeter. We choose a Novalis rather than a Gamma knife because of a huge tumor size and parasagittal location, which often cause a peritumoral edema after a Gamma knife. So, 20 months later, tumor showed partial reduction of size and she improved a lot about her neurological symptoms, so she is now walking.
The second case, cavernous sinus meningioma. She also had operation twice, but recurred tumor. The tumor volume was 50.1 cubic centimeter, quite large. We choose a Novalis because of a large tumor size and involving risk organ. We prescribed a 36 Gray in 9 fraction using the IMRT. So, this is the MRI taken 16 months later. The tumor size unchanged and her neurological symptoms unchanged.
The third case, petro-clival meningioma. The maximum diameter of the tumor was 35 millimeter. There is a higher limit to the Gamma knife, I think. We choose the Novalis treatment, relatively large volume, and also the location, compressing the brainstem. We choose IMRT and the 40 Gray in a 10 fraction was used. Six months later, tumor showed a minor reduction of size but his neurological symptoms improved a lot. So, his facial dysesthesia and diplopia disappeared.
The case four, this is the tumor located very close to the eyeball. I think that this location is very difficult to reach by Gamma knife. So we treated this patient 40 Gray in a 10 fraction. So, she didn't have any changes for six months.
This case gave us the opportunity to reflect on fraction size and prescription of dose. Actually, tumor is very small, although the tumor located in convexity, we gave the 35 Gray in a 5 fraction. This is MRI taken seven months later. You see the progression of disease. Tumor size increased and also, T2 image shows the enlargement of the peritumoral edema. So, now, 18 months later, tumor size shrinked and the edema disappeared. She didn't have any neurological deficits, but still, we can say maybe the prescription dose or a fraction size is inadequate for this patient. We'd better to use a 10 fraction for [inaudible 00:06:05.693] location, I think.
Well, the last patient had a parasagittal meningioma, anaplastic meningioma, WHO grade 3. This is very impressive case. The tumor located in a parasagittal and the size is quite huge, 91.1 cubic centimeter. That is the largest in this series, where we used the IMRT, 35 Gray in a 10 fraction. So, three months later, tumor dramatically shrinked and the patient symptom improved a lot. Well, I understand the anaplastic meningioma will recur in a very short period but still, I can say the initial response is remarkable, so wonderful.
This is summary of our result. Well, we have four determination factors why choosing a Novalis rather than Gamma knife. The first one is tumor size, following involving risk organs, and prevention of edema, and unreachable location by Gamma knife. So our follow up period is very small...short, eight months. But at this point, for imaging outcome, 3 patient had a partial reduction, 10 had a no change, NC, and 2 had a progression of disease. One of this patient had a radiation necrosis and another had a cyst formation. I think that I already shown the previous slide for the radiation necrosis case.
Talking about functional outcome, 3 patient improved and 12 patient unchanged their neurological symptoms.
Discussion. This slide shows the comparison between a SRS and SRT for meningiomas. This is the view from the MGH group published in 2007 Neurosurgical Focus. According to this paper, five years progression for a survivor or a complication rate is very similar in both of groups. But the biggest difference is tumor size. SRT group had a very big tumor size.
And this table shows the summary of new or worsening edema following a Gamma knife SRS. So this table is showing the comparison between a basal and a non-basal location of meningioma. You see, the instance of the peritumoral edema is very high in a non-basal location such as parasagittal [inaudible 00:09:22.961] or convexity. So, I think that this is a weak point of Gamma knife, so fractionated SRT using the Novalis can compensate for it.
This is our conclusion. Fractionated SRT by Novalis is a safe and effective method for meningiomas even if they are impossible to be treated by Gamma knife. Large tumor size, the location around the critical structures, high risk of edema, and unreachable location by Gamma knife can be treated. In the future, the optimal fraction size and dose should be determined. Well, thank you very much for your attention.
Today, I'll be talking about our initial experience of Novalis Stereotactic Radiation Therapy for Gamma-Knife-Untreatable Meningiomas. Of course, Gamma knife is a effective and very safe treatment for meningiomas. The progression for a survival at the five years mark is more than 95%. There is a tremendous achievement, I think. But the indication is somewhat limited because of some factors. So today, we review our initial experience of this treatment and clarified its effectiveness and indication.
Since we started the Novalis treatment in July 2006, we treated more than 200 cases with intracranial tumors. Among of them, 15 patient had a meningioma which are unsuitable for Gamma knife. Tumor dominantly located in a parasagittal region, going suprasella, tentrial confluens, and so on. The average tumor volume was 31 cubic centimeter, ranged up to 91 cubic centimeter. So, quite a huge tumor size group.
According to the pathology, nine patient were grade 1, three were grade 2, and one was grade 3 anaplastic meningioma. While the treatment parameters are...the average of total dose was 36.8 Gray, we must reuse 40 Gray in 10 fraction. In a half of this group, we used IMRT.
Let me go to the demonstrative case. This patient had a parasagittal meningioma, WHO grade 1. She had a recurrent of tumor despite of [inaudible 00:02:39.530] operation. The tumor size is very huge, 52.1 cubic centimeter. We choose a Novalis rather than a Gamma knife because of a huge tumor size and parasagittal location, which often cause a peritumoral edema after a Gamma knife. So, 20 months later, tumor showed partial reduction of size and she improved a lot about her neurological symptoms, so she is now walking.
The second case, cavernous sinus meningioma. She also had operation twice, but recurred tumor. The tumor volume was 50.1 cubic centimeter, quite large. We choose a Novalis because of a large tumor size and involving risk organ. We prescribed a 36 Gray in 9 fraction using the IMRT. So, this is the MRI taken 16 months later. The tumor size unchanged and her neurological symptoms unchanged.
The third case, petro-clival meningioma. The maximum diameter of the tumor was 35 millimeter. There is a higher limit to the Gamma knife, I think. We choose the Novalis treatment, relatively large volume, and also the location, compressing the brainstem. We choose IMRT and the 40 Gray in a 10 fraction was used. Six months later, tumor showed a minor reduction of size but his neurological symptoms improved a lot. So, his facial dysesthesia and diplopia disappeared.
The case four, this is the tumor located very close to the eyeball. I think that this location is very difficult to reach by Gamma knife. So we treated this patient 40 Gray in a 10 fraction. So, she didn't have any changes for six months.
This case gave us the opportunity to reflect on fraction size and prescription of dose. Actually, tumor is very small, although the tumor located in convexity, we gave the 35 Gray in a 5 fraction. This is MRI taken seven months later. You see the progression of disease. Tumor size increased and also, T2 image shows the enlargement of the peritumoral edema. So, now, 18 months later, tumor size shrinked and the edema disappeared. She didn't have any neurological deficits, but still, we can say maybe the prescription dose or a fraction size is inadequate for this patient. We'd better to use a 10 fraction for [inaudible 00:06:05.693] location, I think.
Well, the last patient had a parasagittal meningioma, anaplastic meningioma, WHO grade 3. This is very impressive case. The tumor located in a parasagittal and the size is quite huge, 91.1 cubic centimeter. That is the largest in this series, where we used the IMRT, 35 Gray in a 10 fraction. So, three months later, tumor dramatically shrinked and the patient symptom improved a lot. Well, I understand the anaplastic meningioma will recur in a very short period but still, I can say the initial response is remarkable, so wonderful.
This is summary of our result. Well, we have four determination factors why choosing a Novalis rather than Gamma knife. The first one is tumor size, following involving risk organs, and prevention of edema, and unreachable location by Gamma knife. So our follow up period is very small...short, eight months. But at this point, for imaging outcome, 3 patient had a partial reduction, 10 had a no change, NC, and 2 had a progression of disease. One of this patient had a radiation necrosis and another had a cyst formation. I think that I already shown the previous slide for the radiation necrosis case.
Talking about functional outcome, 3 patient improved and 12 patient unchanged their neurological symptoms.
Discussion. This slide shows the comparison between a SRS and SRT for meningiomas. This is the view from the MGH group published in 2007 Neurosurgical Focus. According to this paper, five years progression for a survivor or a complication rate is very similar in both of groups. But the biggest difference is tumor size. SRT group had a very big tumor size.
And this table shows the summary of new or worsening edema following a Gamma knife SRS. So this table is showing the comparison between a basal and a non-basal location of meningioma. You see, the instance of the peritumoral edema is very high in a non-basal location such as parasagittal [inaudible 00:09:22.961] or convexity. So, I think that this is a weak point of Gamma knife, so fractionated SRT using the Novalis can compensate for it.
This is our conclusion. Fractionated SRT by Novalis is a safe and effective method for meningiomas even if they are impossible to be treated by Gamma knife. Large tumor size, the location around the critical structures, high risk of edema, and unreachable location by Gamma knife can be treated. In the future, the optimal fraction size and dose should be determined. Well, thank you very much for your attention.