Reirradiation of primary CNS tumors.
ABSTRACT Primary central nervous system (CNS) tumors are seldom reirradiated due to toxicity concerns and sparse clinical data regarding efficacy.
We retrospectively reviewed 34 patients with primary brain tumors retreated with fractionated external beam irradiation at the University of California, San Francisco from 1977-1993. Tumors included 15 medulloblastomas, 10 high-grade gliomas, 7 low-grade gliomas, and 2 meningiomas.
Initial course of radiation was radical in intent for all patients. Median age at initial diagnosis was 19.8 years (range: 3.6-67). Median interval between radiation courses was 16.3 months (range: 3.8-166). Median Karnofsky Performance Status (KPS) prior to reirradiation was 80 (range: 40-100). Reirradiation volumes overlapped previous treatment in 30 patients and were nonoverlapping in 4 patients. Fractionation schemes used were hyperfractionated in 17, conventionally fractionated in 9, and hypofractionated in 8. Cumulative maximum overlap dose within the CNS ranged from 43.2-111 Gy (median: 79.7 Gy). Retreatment was completed as planned in 27 out of 34 patients and modified or aborted in 7 (four tumor progression on retreatment, three patient request). As measured from the time of retreatment median progression free and overall survival was 3.3 and 8.3 months. Clinical and radiographic indices were stabilized or improved in about half of patients evaluable at a median of 3 months postretreatment. Complications (early or late) potentially attributable to retreatment were noted in 10 of 34 (29%) of patients. Overt necrosis was noted in 3 of 34 (9%) of patients and the actuarial risk of necrosis was 22% at 1 year following retreatment.
Reirradiation of primary central nervous system tumors was associated with only modest palliative and survival benefits in this retrospective review. Difficulties separating toxicity due to retreatment vs. tumor progression and limited patient survival following retreatment preclude definite conclusions regarding the safety of this practice.
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Chapter: Fractionation Concepts[Show abstract] [Hide abstract]
ABSTRACT: This chapter summarizes the principles of fractionated radiotherapy and altered fractionation approaches. Clinical reirradiation examples and isoeffect calculations are provided. The vast majority of published reirradiation series consist of retrospective data or small prospective studies with limited statistical power. In addition, the typical patient populations are more heterogeneous than in first-line radiotherapy studies. For example, patients with local relapse, regional relapse, or second primary tumors might be included. Therefore, the level of evidence is not comparable to that of first-line radiotherapy, where many treatment recommendations and guidelines are based on large and well-designed prospective randomized trials or meta-analyses of several trials. Reirradiation is often used for palliative symptoms but occasionally curative approaches, which require high total radiation doses, might be possible. Hyperfractionated reirradiation might theoretically improve the therapeutic ratio, but prospective trials are required to confirm this hypothesis.03/2011: pages 13-26;
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ABSTRACT: High-grade astrocytomas include the most common adult central nervous system (CNS) tumor, glioblastoma multiforme, and anaplastic astrocytoma--a highly aggressive cancer with short median survival despite maximal multimodality therapy. Diagnosis is by clinical and radiographic findings confirmed by histopathology. Standard-of-care therapy includes surgical resection, radiotherapy, and temozolomide. Nearly all patients who have high-grade astrocytomas develop tumor recurrence or progression after this multimodality treatment. Two treatment challenges are molecular/genetic heterogeneity of tumors and limited CNS tumor delivery. It is probable that targeted therapies will be most effective in combination with one another or with cytotoxic therapies. This article discusses diagnosis and current treatment of high-grade astrocytomas.Neurologic Clinics 12/2007; 25(4):1111-39, x. DOI:10.1016/j.ncl.2007.07.004 · 1.61 Impact Factor
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ABSTRACT: Die primäre Therapie des Glioblastoma multiforme ist die Bestrahlung mit simultaner und nachfolgender Temodaltherapie. Die Therapie im Rezidivfall wird kontroversiell diskutiert und ist nicht standardisiert. In mehreren Serien wird die Machbarkeit der Re-Bestrahlung beschrieben. Randomisierte Studien fehlen allerdings. Mit neuen hoch präzisen Bestrahlungsmethoden zeigen sich gute Effekte mit geringer Toxizität. Ein medianes Überleben von 6–12 Monaten lässt sich erzielen. Die zusätzliche Verabreichung einer Chemotherapie oder einer zielgerichteten Therapie kann mit erhöhter Toxizität verbunden sein und wird in Studien geprüft. Die Indikation zur Re-Bestrahlung ist an Hand der individuellen Situation zu stellen. Der mögliche negative Einfluss der Re-Bestrahlung auf die Lebensqualität ist unbedingt zu berücksichtigen. Patients with glioblastoma are treated by radiotherapy in combination with temozolamid. Recurrent and progressive disease can be managed by several treatment options. Some series reported about reirradiation of brain tumors, but there are no randomised studies. Modern high precise radiation techniques can be an option for a save and effective treatment without systemic side effects. The published series show median survival rates from 6 to 12 months. Concomitant systemic therapies are evaluated in phase I/II studies. Indication for irradiation and decision of the technique and fractionation scheme have to be chosen individually. There is no curative intent for reirradiation, possible serious side effects and negative influence on life quality have to be omitted. SchlüsselwörterRe-Bestrahlung–Maligne Gliome KeywordsReirradiation–Highgrade gliomaWiener Medizinische Wochenschrift 01/2011; 161(1):22-25. DOI:10.1007/s10354-010-0862-6