Department of Radiation Oncology, Tenon Hospital, Paris, France.
Abstract
PURPOSE:
Stereotactic radiotherapy delivered in a high-dose single fraction is an effective technique to obliterate intracranial arteriovenous malformations (AVM). To attempt to analyze the relationships between dose, volume, and obliteration rates, we studied a group of patients treated using single-isocenter treatment plans.
METHODS AND MATERIALS:
From May 1986 to December 1989, 100 consecutive patients with angiographically proven AVM had stereotactic radiotherapy delivered as a high-dose single fraction using a single-isocenter technique. Distribution according to Spetzler-Martin grade was as follows: 79 grade 1-3, three grade 4, 0 grade 5, and 18 grade 6. The target volume was spheroid in 74 cases, ellipsoid in 11, and large and irregular in 15. The targeted volume of the nidus was estimated using two-dimensional stereotactic angiographic data and, calculated as an ovoid-shaped lesion, was 1900 +/- 230 mm3 (median 968 mm3; range 62-11, 250 mm3). The mean minimum target dose (Dmin) was 19 +/- 0.6 Gy (median 20 Gy; range: 3-31.5). The mean volume within the isodose which corresponded to the minimum target dose was 2500 +/- 300 mm3 (median 1200 mm3; range 75-14 900 mm3). The mean maximum dose (Dmax) was 34.5 +/- 0.5 Gy (median 35 Gy; range 15-45). The mean angiographic follow-up was 42 +/- 2.3 months (median 37.5; range 7-117).
RESULTS:
The absolute obliteration rate was 51%. The 5-year actuarial obliteration rate was 62.5 +/- 7%. After univariate analysis, AVM obliteration was influenced by previous surgery (p = 0.0007), Dmin by steps of 5 Gy (p = 0.005), targeted volume of the nidus (< or = 968 mm3 vs. >968 mm3; p = 0.015), and grade according to Spetzler-Martin (grade 1-3 vs. grade 4-6; p = 0.011). After multivariate analysis, the independent factors influencing AVM obliteration were the Dmin [relative risk (RR) 1.9; 95% confidence interval (CI) 1.4-2.5; p < 0.0001] and grade distribution according to Spetzler-Martin (RR 1.4; 95% CI 1.1-1.7; p = 0.010). Delayed complications were observed in eight patients. The 5-year actuarial rate of delayed complications was 7.4%.
CONCLUSION:
After stereotactic radiotherapy delivered in a single high dose using a single-isocenter technique, the success rate for complete obliteration is independently correlated to Dmin but does not seem to be influenced by Dmax and the targeted volume of the nidus.
Department of Radiation Oncology, University of Pittsburgh School of Medicine, PA 15213, USA.
Abstract
PURPOSE:
Although radiosurgery is effective in obliterating the pathologic vessels of intracranial arteriovenous malformations (AVM), the relationships of both dose and volume to obliteration have not been well defined.
METHODS AND MATERIALS:
The results of radiosurgery in 197 AVM patients with 3-year angiographic follow-up were analyzed. Volume varied from 0.06-18 cc (median: 4.1 cc), and minimum target dose (Dmin) varied from 12.0-25.6 Gy (median: 20.0 Gy).
RESULTS:
Follow-up angiography revealed complete AVM obliteration in 142 out of 197 patients (72%). The targeted AVM nidus failed to obliterate in 20 patients (10%), but in-field obliteration was complete in the remaining 35 patients (18%) discovered to have residual untargeted AVM nidus. Multivariate logistic regression analysis of in-field obliteration revealed a significant independent correlation with Dmin (p = 0.04), but not with volume or maximum dose. A sigmoid dose-response curve for in-field obliteration was constructed that significantly differed from the dose-volume-response relationships that would have been expected from overall obliteration data.
CONCLUSIONS:
The success rate for in-field obliteration of AVM after radiosurgery depends on Dmin but does not appear to change appreciably with volume or maximum dose. Success rates for complete obliteration additionally are limited by problems defining the complete AVM nidus.
*Division of Neurological Surgery, Department of Surgery, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.; ** Department of Neurological Surgery, Stanford University School of Medicine, Stanford, California; *** Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; ****Division of Neurological Surgery, The Kaiser Permanente Medical Group, Redwood City, California.
Abstract
BACKGROUND: Single session stereotactic radiosurgery (SRS) treatment of vestibular schwannomas (VS) results in excellent tumor control. It is not known if functional outcomes can be improved by fractionating the treatment over multiple sessions. OBJECTIVE: To examine tumor control and complication rates following multi-session SRS. METHODS: Three hundred and eighty-three patients treated with SRS from 1999 to 2007 at Stanford University Medical Center were retrospectively reviewed. Ninety percent were treated with 18 Gy in 3 sessions, targeting a median tumor volume of 1.1 cm (range, 0.02-19.8 cm). RESULTS: With a median follow-up duration of 3.6 years (range, 1-10 years), 10 tumors required additional treatment, resulting in 3- and 5-year Kaplan-Meier tumor control rates of 99%, and 96%, respectively. Five-year tumor control rate was 98% for tumors less than 3.4 cm. NF2-associated tumors were associated with worse tumor control (p=0.018). Of the 200 evaluable patients with pre-SRS serviceable hearing (Gardner-Robertson Grade 1 and 2), the crude rate of serviceable hearing preservation was 76%. Smaller tumor volume was associated with hearing preservation (p=0.001). There was no case of post-SRS facial weakness. Eight patients (2%) developed trigeminal dysfunction, half of which was transient. CONCLUSION: Multi-session SRS treatment of VS results in an excellent rate of tumor control. Hearing, trigeminal nerve, and facial nerve function preservation rates reported herein are promising.
Section of Neurosurgery, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico.
Abstract
Object
The purpose of this study was to describe a 10-year experience in the use of radiosurgery (RS) for patients with arteriovenous malformations (AVMs) in Puerto Rico. Methods
This retrospective analysis was performed for all patients with AVMs treated with RS by the senior author (R.H.B.) in Puerto Rico. Between February 1999 and December 2009, a total of 83 patients underwent the procedure. All charts were reviewed for recollection of demographic data, and AVM and treatment characteristics. Clinical and radiographic follow-up information was collected retrospectively. Results Eighty-three patients were treated and 86 RS procedures for AVMs were performed during a 10-year period. Eight patients were lost to follow-up. The remaining 75 patients included 36 males and 39 females, whose median age was 34.5 years. Hemorrhage was the initial presentation in 40% of patients. Fifty-seven AVMs (73%) were treated previously with endovascular neurosurgery, without success. The median volume of the malformation was 17.7 ml. Nearly 65% of the malformations were considered large (≥ 10 ml) in volume. Forty patients had AVMs with largest diameter ≥ 3.5 cm. The overall obliteration rate was 56.4%, and the median time for obliteration was 29 months. The AVMs ≥ 3.5 cm in diameter had a greater latency period than those < 3.5 cm (31 months vs 46 months, respectively; p = 0.01). In addition, AVM obliteration was inversely associated with its volume, especially in large lesions (p = 0.037). In bivariate analysis, patients achieving obliteration had lower Spetzler-Martin scores compared with patients in whom obliteration was not achieved (p = 0.009). Postradiosurgery hemorrhages were seen in 9 cases. Eleven patients underwent surgery after RS. Major neurological deficits developed in 9 patients, whereas 17 had only minor deficits. The occurrence of neurological deficits was significantly associated with lesions with volume ≥ 10 ml. Conclusions Radiosurgery is a reasonable treatment option for AVMs in the majority of cases, in spite of the large, difficult-to-treat malformations.
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INFORMACIÓN:
En esta pagina encontrara información actualizada de la oncología radioterapica del siglo XXI, dirigido a estudiantes de medicina, Residentes de medicina y médicos en general.
Definición ministerio de educación y ciencia:
La Oncología Radioterápica es una especialidad médica dedicada a los aspectos diagnósticos, cuidados clínicos y terapéuticos del enfermo oncológico, primordialmente orientada al empleo de los tratamientos con radiaciones, así como al uso y valoración relativa de los tratamientos alternativos o asociados e Investigación y Docencia.
Definición PSICOONCOLOGÍA. Vol. 1, Núm. 1, 2004, pp. 13-30
En los últimos años, en España, se ha incrementado tanto la incidencia del cáncer como su mortalidad, hasta ocupar el segundo lugar tras las enfermedades cardiovasculares, a pesar de que con los métodos terapéuticos actuales pue-den curarse la mitad de los pacientes con esta enfermedad.
La Oncología Radioterápica es una especialidad médica dedicada a los aspectos diagnósticos, cuidados clínicos y terapéuticos del enfermo oncológico. Desde el descubrimiento de los rayos X y la radiactividad natural a finales del siglo XIX hasta la actualidad, esta especialidad ha experimentado un gran desarrollo tanto a nivel de avances tecnológicos como de incremento del índice terapéutico. A esto ha contribuido, en los últimos años, el mejor conocimiento de las bases moleculares del cáncer así como los progresos radiobiológicos.
La radioterapia es un arma terapéutica fun- damental en la curación de los tumores y que puede ser utilizada de forma exclusiva o asocia- da a otros tratamientos.
