Gamma knife radiosurgery for pilocytic astrocytomas

2002 ◽  
Vol 97 ◽  
pp. 677-680 ◽  
Author(s):  
Jörgen Boëthius ◽  
Elvar Ulfarsson ◽  
Tiit Ráhn ◽  
Bodo Lippitz
Keyword(s):  
Side Effects ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Content Type ◽  
Natural Time ◽  
Pilocytic Astrocytomas ◽  
Follow Up Studies ◽  
Prescription Dose ◽  
Fine Print

Object. The authors report on the follow-up studies in patients treated at the Karolinska Hospital to evaluate the efficacy of gamma knife radiosurgery (GKS) for pilocytic astrocytoma. Methods. Twelve male and seven female patients were treated (mean age 10.6 years [range 2–60 years]). Sixteen of these patients were children in whom GKS was performed to treat residual tumor after surgery. Most tumors were treated with a prescription dose of 10 to 12 Gy (range 9–20 Gy). The corresponding maximum dose varied between 22 and 30 Gy (range 10–50 Gy). The median clinical follow-up time was 7 years and mean clinical follow-up time 8.5 years. Median radiological follow-up time was 4.7 years and the mean radiological follow-up time was 5.9 years. Tumor control was achieved in all patients. In 85% of the cases a moderate tumor volume reduction was observed after GKS. This result occurred despite the low prescription dose administered. The radiological follow-up studies showed adverse radiation effects in 25% of patients with increasing contrast enhancement and some edema. These effects generally appeared within 7 months and resolved later. Cyst development occurred in two patients, which may have been treatment related. Conclusions. It appears that small pilocytic astrocytomas may be treated with low-prescription-dose GKS, resulting in satisfactory clinical outcomes and only minor side effects. There were a certain number of radiologically demonstrated side effects that appeared relatively early but subsequently resolved. This study should be regarded as a preliminary one because the number of patients is small and the follow-up period is short compared with the natural time course of the disease.

Gamma knife radiosurgery as a single treatment modality for large cerebral arteriovenous malformations

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 113-119 ◽  
Author(s):  
D. Hung-Chi Pan ◽  
Wan-Yuo Guo ◽  
Wen-Yuh Chung ◽  
Cheng-Ying Shiau ◽  
Yue-Cune Chang ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Radiation Treatment ◽  
Gamma Knife Radiosurgery ◽  
Consecutive Series ◽  
Content Type ◽  
Obliteration Rate ◽  
Complete Obliteration ◽  
Fine Print

Object. A consecutive series of 240 patients with arteriovenous malformations (AVMs) treated by gamma knife radiosurgery (GKS) between March 1993 and March 1999 was evaluated to assess the efficacy and safety of radiosurgery for cerebral AVMs larger than 10 cm3 in volume. Methods. Seventy-six patients (32%) had AVM nidus volumes of more than 10 cm3. During radiosurgery, targeting and delineation of AVM nidi were based on integrated stereotactic magnetic resonance (MR) imaging and x-ray angiography. The radiation treatment was performed using multiple small isocenters to improve conformity of the treatment volume. The mean dose inside the nidus was kept between 20 Gy and 24 Gy. The margin dose ranged between 15 to 18 Gy placed at the 55 to 60% isodose centers. Follow up ranged from 12 to 73 months. There was complete obliteration in 24 patients with an AVM volume of more than 10 cm3 and in 91 patients with an AVM volume of less than 10 cm3. The latency for complete obliteration in larger-volume AVMs was significantly longer. In Kaplan—Meier analysis, the complete obliteration rate in 40 months was 77% in AVMs with volumes between 10 to 15 cm3, as compared with 25% for AVMs with a volume of more than 15 cm3. In the latter, the obliteration rate had increased to 58% at 50 months. The follow-up MR images revealed that large-volume AVMs had higher incidences of postradiosurgical edema, petechiae, and hemorrhage. The bleeding rate before cure was 9.2% (seven of 76) for AVMs with a volume exceeding 10 cm3, and 1.8% (three of 164) for AVMs with a volume less than 10 cm3. Although focal edema was more frequently found in large AVMs, most of the cases were reversible. Permanent neurological complications were found in 3.9% (three of 76) of the patients with an AVM volume of more than 10 cm3, 3.8% (three of 80) of those with AVM volume of 3 to 10 cm3, and 2.4% (two of 84) of those with an AVM volume less than 3 cm3. These differences in complications rate were not significant. Conclusions. Recent improvement of radiosurgery in conjunction with stereotactic MR targeting and multiplanar dose planning has permitted the treatment of larger AVMs. It is suggested that gamma knife radiosurgery is effective for treating AVMs as large as 30 cm3 in volume with an acceptable risk.

Factors related to complete occlusion of arteriovenous malformations after gamma knife radiosurgery

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 96-101 ◽  
Author(s):  
Jong Hee Chang ◽  
Jin Woo Chang ◽  
Yong Gou Park ◽  
Sang Sup Chung
Keyword(s):  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Gamma Knife Radiosurgery ◽  
Maximum Diameter ◽  
Content Type ◽  
Complete Occlusion ◽  
Factors Associated ◽  
Martin Grade ◽  
Fine Print

Object. The authors sought to evaluate the effects of gamma knife radiosurgery (GKS) on cerebral arteriovenous malformations (AVMs) and the factors associated with complete occlusion. Methods. A total of 301 radiosurgical procedures for 277 cerebral AVMs were performed between December 1988 and December 1999. Two hundred seventy-eight lesions in 254 patients who were treated with GKS from May 1992 to December 1999 were analyzed. Several clinical and radiological parameters were evaluated. Conclusions. The total obliteration rate for the cases with an adequate radiological follow up of more than 2 years was 78.9%. In multivariate analysis, maximum diameter, angiographically delineated shape of the AVM nidus, and the number of draining veins significantly influenced the result of radiosurgery. In addition, margin radiation dose, Spetzler—Martin grade, and the flow pattern of the AVM nidus also had some influence on the outcome. In addition to the size, topography, and radiosurgical parameters of AVMs, it would seem to be necessary to consider the angioarchitectural and hemodynamic aspects to select proper candidates for radiosurgery.

Gamma knife radiosurgery for uveal melanomas: an 8-year experience

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 184-188 ◽  
Author(s):  
Gerald Langmann ◽  
Gerhard Pendl ◽  
Georg Papaefthymiou ◽  
Helmuth Guss ◽  
Keyword(s):  
Gamma Knife ◽  
Ciliary Body ◽  
Tumor Regression ◽  
Gamma Knife Radiosurgery ◽  
Neovascular Glaucoma ◽  
Content Type ◽  
Prescription Dose ◽  
The Mean ◽  
Fine Print ◽  
Uveal Melanomas

Object. The authors report their experience using gamma knife radiosurgery (GKS) to treat uveal melanomas. Methods. Between 1992 and 1998, 60 patients were treated with GKS at a prescription dose between 45 Gy and 80 Gy. The mean diameter of the tumor base was 12.2 mm (range 3–22 mm). The mean height of the tumor prominence was 6.7 mm (range 3–12 mm). The eye was immobilized. The follow-up period ranged from 16 to 94 months. Tumor regression was achieved in 56 (93%) of 60 patients. There were four recurrences followed by enucleation. The severe side effect of neovascular glaucoma developed in 21 (35%) patients in a high-dose group with larger tumors and in proximity to the ciliary body. A reduction in the prescription dose to 40 Gy or less and excluding treatment to tumors near the ciliary body decreased the rate of glaucoma without affecting the rate of tumor control. Conclusions. Gamma knife radiosurgery at a prescription dose of 45 Gy or more can achieve tumor regression in 85% of the uveal melanomas treated. Neovascular glaucoma can develop in patients when using this dose in tumors near the ciliary body. It is advised that such tumors be avoided and that the prescription dose be reduced to 40 Gy.

Gamma knife radiosurgery as a lesioning technique in movement disorder surgery

1998 ◽  
Vol 89 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Ronald F. Young ◽  
Anne Shumway-Cook ◽  
Sandra S. Vermeulen ◽  
Peter Grimm ◽  
John Blasko ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Movement Disorder ◽  
Gamma Knife ◽  
Movement Disorders ◽  
Gamma Knife Radiosurgery ◽  
Safety And Efficacy ◽  
Content Type ◽  
Fine Print

Object. To increase knowledge of the safety and efficacy of the use of gamma knife radiosurgery in patients with movement disorders, the authors describe their own experience in this field and include blinded independent assessments of their results. Methods. Fifty-five patients underwent radiosurgical placement of lesions either in the thalamus (27 patients) or globus pallidus (28 patients) for treatment of movement disorders. Patients were evaluated pre- and postoperatively by a team of observers skilled in the assessment of gait and movement disorders who were blinded to the procedure performed. The observers were not associated with the surgical team and concomitantly and blindly also assessed a group of 11 control patients with Parkinson's disease who did not undergo any surgical procedures. All stereotactic lesions were made with the Leksell gamma unit using the 4-mm secondary collimator helmet and a single isocenter with maximum doses from 120 to 160 Gy. Clinical follow-up evaluation indicated that 88% of patients who underwent thalamotomy became tremor free or nearly tremor free. Statistically significant improvements in performance were noted in the independent assessments of Unified Parkinson's Disease Rating Scale (UPDRS) scores in the patients undergoing thalamotomy. Of patients undergoing pallidotomy who had exhibited levodopainduced dyskinesias, 85.7% had total or near-total relief of that symptom. Clinical assessment indicated improvements in bradykinesia and rigidity in 64.3% of patients who underwent pallidotomy. Independent blinded assessments did not reveal statistically significant improvements in Hoehn and Yahr scores or UPDRS scores. On the other hand, 64.7% of patients showed improvements in subscores of the UPDRS, including activities of daily living (58%), total contralateral score (58%), and contralateral motor scores (47%). Total ipsilateral score and ipsilateral motor scores were both improved in 59% of patients. One (1.8%) of 55 patients experienced a homonymous hemianopsia 9 months after pallidotomy due to an unexpectedly large lesion. No other complications of any kind were seen. Neuropsychological test scores that were obtained for the combined pallidotomy and thalamotomy treatment groups preoperatively and at 6 months postoperatively demonstrated an absence of cognitive morbidity. Follow-up neuroimaging confirmed correct lesion location in all patients, with a mean maximum deviation from the planned target of 1 mm in the vertical axis. Measurements of lesions at regular intervals on postoperative magnetic resonance images demonstrated considerable variability in lesion volumes. The safety and efficacy of functional lesions made with the gamma knife appear to be similar to those made with the assistance of electrophysiological guidance with open functional stereotactic procedures. Conclusions. Functional lesions may be made safely and accurately using gamma knife radiosurgical techniques. The efficacy is equivalent to that reported for open techniques that use radiofrequency lesioning methods with electrophysiological guidance. Complications are very infrequent with the radiosurgical method. The use of functional radiosurgical lesioning to treat movement disorders is particularly attractive in older patients and in those with major systemic diseases or coagulopathies; its use in the general movement disorder population seems reasonable as well.

The long-term results of gamma knife radiosurgery for hemangioblastomas of the brain

2005 ◽  
Vol 102 ◽  
pp. 225-229 ◽  
Author(s):  
En-Min Wang ◽  
Li Pan ◽  
Bing-Jiang Wang ◽  
Nan Zhang ◽  
Liang-Fu Zhou ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Tumor Control ◽  
Content Type ◽  
Prescription Dose ◽  
The Mean ◽  
Vhl Disease ◽  
The Brain ◽  
Fine Print

Object. The authors assessed the long-term result of gamma knife surgery (GKS) for hemangioblastomas of the brain (HABs) and show histopathological findings after GKS. Methods. Thirty-five patients, 28 men and seven women, with a mean age of 36 years underwent GKS. Eighteen patients presented with multiple tumors and 17 with a solitary tumor. Twenty-one patients had von Hippel—Lindau (VHL) disease. The mean tumor diameter was 13 mm (range 5–55 mm). The mean follow up after GKS was 66 months (range 24–114 months). The mean prescription dose was 17.2 Gy (range 12–24 Gy) at the tumor margin. For tumors close to or within the brainstem a prescription dose of 12 to 13 Gy was used. At the most recent follow up, 29 patients were alive, six were dead, and satisfactory tumor control had been achieved in 29. A stable or improved neurological status was obtained in 21 patients. Eight patients underwent open surgery because of tumor-associated cyst enlargement or the development of new tumors after GKS. Seven patients developed new tumors and five of them required a second GKS. The 1-year tumor control rate was 94%; 2 years, 85%; 3 years, 82%; 4 years, 79%; and 5 years, 71%. Histopathology showed that no tumor cells were found and there was degeneration and necrosis in a tumor nodule 48 months after GKS with a prescription dose of 18 Gy. Conclusions. Gamma knife surgery was a useful choice for small- or medium-sized, solid HAB in the long term, especially when the tumor margin dose was 18 Gy. Although GKS can treat multiple tumors in a single session, for HABs associated with VHL disease, GKS faces the dual problems of tumor recurrence or development of a new tumor.

Radiosurgery for Cushing's disease after failed transsphenoidal surgery

2000 ◽  
Vol 93 (5) ◽  
pp. 738-742 ◽  
Author(s):  
Jonas M. Sheehan ◽  
Mary L. Vance ◽  
Jason P. Sheehan ◽  
Dilantha B. Ellegala ◽  
Edward R. Laws
Keyword(s):  
Gamma Knife ◽  
Cushing’S Disease ◽  
Tumor Size ◽  
Transsphenoidal Surgery ◽  
Gamma Knife Radiosurgery ◽  
Magnetic Resonance Images ◽  
Cushing's Disease ◽  
Content Type ◽  
Fine Print

Object. Although transsphenoidal surgery has become the standard of care for Cushing's disease, it is often unsuccessful in normalizing cortisol production. In this study the authors investigate the safety and efficacy of gamma knife radiosurgery (GKRS) for Cushing's disease after failed transsphenoidal surgery.Methods. The records of all patients who underwent GKRS at the authors' institution after unsuccessful transsphenoidal surgery for Cushing's disease were retrospectively reviewed. Successful treatment was considered a normal or below-normal 24-hour urinary free cortisol (UFC) level. Records were also evaluated for relapse, new-onset endocrine deficiencies, interval change in tumor size, and visual complications.Forty-three patients underwent 44 gamma knife procedures with follow up ranging from 18 to 113 months (mean 39.1, median 44 months). Normal 24-hour UFC levels were achieved in 27 patients (63%) at an average time from treatment of 12.1 months (range 3–48 months). Three patients had a recurrence of Cushing's disease at 19, 37, and 38 months, respectively, after radiosurgery. New endocrine deficiencies were noted in seven patients (16%). Follow-up magnetic resonance images obtained in 33 patients revealed a decrease in tumor size in 24, no change in nine, and an increase in size in none of the patients. One patient developed a quadrantanopsia 14 months after radiosurgery despite having received a dose of only 0.7 Gy to the optic tract.Conclusions. Gamma knife radiosurgery appears to be safe and effective for the treatment of Cushing's disease refractory to pituitary surgery. Delayed recurrences and new hormone deficiencies may occur, indicating the necessity for regular long-term follow up.

Analysis of the causes of treatment failure in gamma knife radiosurgery for intracranial arteriovenous malformations

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 104-106 ◽  
Author(s):  
Yang Kwon ◽  
Sang Ryong Jeon ◽  
Jeong Hoon Kim ◽  
Jung Kyo Lee ◽  
Dong Sook Ra ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Treatment Failure ◽  
Gamma Knife ◽  
Arteriovenous Malformations ◽  
Gamma Knife Radiosurgery ◽  
Intracranial Arteriovenous Malformations ◽  
Content Type ◽  
The Mean ◽  
Fine Print

Object. The authors sought to analyze causes for treatment failure following gamma knife radiosurgery (GKS) for intracranial arteriovenous malformations (AVMs), in cases in which the nidus could still be observed on angiography 3 years postsurgery. Methods. Four hundred fifteen patients with AVMs were treated with GKS between April 1990 and March 2000. The mean margin dose was 23.6 Gy (range 10–25 Gy), and the mean nidus volume was 5.3 cm3 (range 0.4–41.7 cm3). The KULA treatment planning system and conventional subtraction angiography were used in treatment planning. One hundred twenty-three of these 415 patients underwent follow-up angiography after GKS. After 3 years the nidus was totally obliterated in 98 patients (80%) and partial obliteration was noted in the remaining 25. There were several reasons why complete obliteration was not achieved in all cases: inadequate nidus definition in four patients, changes in the size and location of the nidus in five patients due to recanalization after embolization or reexpansion after hematoma reabsorption, a large AVM volume in five patients, a suboptimal radiation dose to the thalamic and basal ganglia in eight patients, and radioresistance in three patients with an intranidal fistula. Conclusions. The causes of failed GKS for treatment of AVMs seen on 3-year follow-up angiograms include inadequate nidus definition, large nidus volume, suboptimal radiation dose, recanalization/reexpansion, and radioresistance associated with an intranidal fistula.

Acute symptoms after gamma knife radiosurgery

2002 ◽  
Vol 97 ◽  
pp. 631-634 ◽  
Author(s):  
E. J. St. George ◽  
J. Kudhail ◽  
J. Perks ◽  
P. N. Plowman
Keyword(s):  
Adverse Events ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Neurological Dysfunction ◽  
Content Type ◽  
Lesion Type ◽  
Patient Groups ◽  
Pin Site ◽  
Fine Print

Object. The purpose of this study was to examine the widely held assumption that early-onset symptoms after gamma knife radiosurgery (GKS) are uncommon. The study was designed to include all types of morbidity and not just those that lead to neurological dysfunction. It was hoped that the results of the study could lead to a more rational follow-up protocol. Methods. Data regarding adverse events were collected prospectively (within 2–3 weeks post-GKS) by telephone interview from 47 of the first 65 patients who could be reached. Immediate adverse events were defined as any new or unexpected symptom developing within 2 weeks of treatment and were graded as mild, moderate, or severe. Two thirds of all patients complained of new adverse symptoms; three patients required prolonged hospitalization, although in one case this was not related to the radiosurgery. The majority of symptomatic patients (91%) experienced mild or moderate complications. More than 50% of patients had headache. One third described pin site—related complications and one fifth suffered from nausea/vomiting or marked tiredness. Patients with moderate symptoms had a larger mean tumor volume and higher radiation dose than other patient groups. Prior radiation therapy, lesion type, or the posttreatment administration of steroid agents did not significantly influence the development of acute symptoms. Conclusions. Acute adverse events following GKS are not uncommon if all types of morbidity are considered. An increased appreciation of these other complications may improve posttreatment care.

A planned combined stereotactic approach for cystic intracranial tumors

2002 ◽  
Vol 97 ◽  
pp. 610-612 ◽  
Author(s):  
Wael Abdel Halim Reda ◽  
Alla Abdel Hay ◽  
Jeremy C. Ganz
Keyword(s):  
Gamma Knife Radiosurgery ◽  
Target Volume ◽  
Cytotoxic Agents ◽  
Content Type ◽  
Cystic Component ◽  
Prescription Dose ◽  
Special Circumstances ◽  
Mural Nodules ◽  
Fine Print

✓ Cyst-associated tumors are classified as cysts with neoplastic mural nodules and intratumoral cysts. The solid component of many of these tumors may be appropriate for gamma knife radiosurgery (GKS). At present there is no systematic protocol for GKS treatment of patients harboring tumors with a cystic component. The purpose of this paper is to suggest such a program. Two cases are presented. One patient had a hemangioblastoma with a cyst and a mural nodule. The second patient had a craniopharyngioma with one large and two small intratumoral cysts. The course in both cases has been satisfactory in the short term. Although the 1-year follow-up period, however, does not provide a basis for determining the correct overall management of such tumors, the treatment strategy does illustrate a program for the management of tumors with associated cysts. Cysts with tumor nodules in their walls should first be treated with GKS followed by aspiration of the cyst contents, unless special circumstances make this unsuitable. This strategy enables treatment planning to take advantage of the natural barrier a cyst may place between a tumor and important surrounding structures. Intratumoral cysts may be aspirated and then treated with GKS, with every attempt made to cover the entire target volume including any residual cyst with the prescription dose. This form of treatment requires very careful follow up. It is probable that in some cases reaccumulation of cyst fluid may require the insertion of an Ommaya reservoir for repeated aspiration or the installation of cytotoxic agents such as bleomycin. This form of treatment is much less traumatic than surgery and does not hinder the performance of subsequent surgery, should this become necessary.

Gamma knife radiosurgery for trigeminal neuralgia: the dry-eye complication

2002 ◽  
Vol 97 ◽  
pp. 525-528 ◽  
Author(s):  
Shinji Matsuda ◽  
Toru Serizawa ◽  
Makato Sato ◽  
Junichi Ono
Keyword(s):  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Dry Eye ◽  
Trigeminal Nerve ◽  
Gamma Knife Radiosurgery ◽  
Ophthalmological Examination ◽  
Related Factors ◽  
Content Type ◽  
Fine Print

Object. The purpose of this paper is to report a unique complication of gamma knife radiosurgery (GKS) for trigeminal neuralgia (TN). The nature of this complication and its related factors are discussed. Methods. Forty-one medically refractory patients with TN were treated with GKS. All patients received 80 Gy to the proximal trigeminal nerve root, using a 4-mm collimator and a single isocenter. Follow up consisted of three monthly outpatient sessions after GKS. Improvement, recurrence, complications, and changes in magnetic resonance imaging were recorded. To evaluate the factors behind the complications, a subgroup of 33 patients was assessed in whom the follow-up duration was more than 9 months. The follow-up duration was 3 to 36 months (mean 13 months). The results were excellent in 20 patients, good in 11, and fair in seven. No patient had a poor result. Three patients suffered recurrences. Seven patients suffered complications 9 to 24 months after GKS. All seven patients complained of facial numbness and hypesthesia was recorded. Three of them also complained of “dry eye” with diminution or absence of corneal reflex but no other abnormalities of the cornea and conjunctiva were found on ophthalmological examination. In these three patients, hypesthesia of the first division of the trigeminal nerve area had been found before their “dry eye” symptoms appeared. The irradiated volume on the brainstem was significantly related to this complication. Conclusions. The dry eye symptom seems to be a special form of sensory disturbance. An overdose of radiation to the brainstem may play an important role in the manifestation of this complication.

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