Linear accelerator-based stereotactic radiosurgery in recurrent glioblastoma: A single center experience

Abstract

Background/Aim. Management of patients with recurrent glioblastoma (GB) comprises a therapeutic challenge in neurooncology owing to the aggressive nature of the disease with poor local control despite a combined modality treatment. The majority of cases recur within the highdose radiotherapy field limiting the use of conventional techniques for re-irradiation due to potential toxicity. Stereotactic radiosurgery (SRS) offers a viable noninvasive therapeutic option in palliative treatment of recurrent GB as a sophisticated modality with improved setup accuracy allowing the administration of high-dose, precise radiotherapy. The aim of the study was to, we report our experience with single-dose linear accelerator (LINAC) based SRS in the management of patients with recurrent GB. Methods. Between 1998 and 2010 a total of 19 patients with recurrent GB were treated using single-dose LINAC-based SRS. The median age was 47 (23-65) years at primary diagnosis. Karnofsky Performance Score was ? 70 for all the patients. The median planning target volume (PTV) was 13 (7-19) cc. The median marginal dose was 16 (10-19) Gy prescribed to the 80%-95% isodose line encompassing the planning target volume. The median follow-up time was 13 (2-59) months. Results. The median survival was 21 months and 9.3 months from the initial GB diagnosis and from SRS, respectively. The median progression-free survival from SRS was 5.7 months. All the patients tolerated radiosurgical treatment well without any Common Toxicity Criteria (CTC) grade > 2 acute side effects. Conclusion. Single-dose LINAC-based SRS is a safe and well- tolerated palliative therapeutic option in the management of patients with recurrent GB.Uvod/Cilj. Lecenje bolesnika sa recidivantnim glioblastomom (GB) predstavlja terapijski izazov u neuroonkologiji zbog agresivne prirode bolesti i lose lokalne kontrole, uprkos kombinovanom lecenju. Najveci broj bolesnika dobije recidiv, iako prima visokodoznu radioterapiju u ogranicenom predelu. Konvencionalne tehnike reiradijacije imaju ogranicenu primenu zbog potencijalne toksicnosti. Stereotaksicna radiohirurgija (SRH) predstavlja neinvazivnu terapijsku opciju u palijativnom lecenju rekurentnog GB kao soficistirani modalitet sa unapredjenom preciznoscu podesavanja cime se omogucava primena visokodozne, precizne radioterapije. Cilj ove studije bio je da se prikazu sopstvena iskustva sa primenom jednodozne SRH uz koriscenje linearnog akceleratora (LINAC) u lecenju bolesnika sa rekurentnim GB. Metode. U periodu od 1998. do 2010. godine leceno je 19 bolesnika sa rekurentnim GB koriscenjem linearnog akceleratora za jednodoznu SRH. Prosecna starost bolesnika pri postavljanju dijagnoze bila je 47 (23-65) godina. Karnofsky Performance Score bio je ? 70 kod svih bolesnika. Prosecni planirani ciljni volumen (median planning target volume - PTV) bio je 13 (7-19) cc. Prosecna marginalna doza iznosila je 16 (10-19) Gy i bila je odredjena za 80- 95% izodozne linije, ispunjavajuci tako planirani ciljni volumen. Prosecno vreme pracenja bilo je 13 (2-59) meseci. Rezultati. Prosecno prezivljavanje bolesnika iznosilo je 21 mesec, tj. 9,3 meseca od uspostavljanja inicijalne dijagoze GB i primene SRS. Prosecni interval od SRS do progresije bolesti iznosio je 5,7 meseci. Svi bolesnici dobro su podnosili radiohirursko lecenje bez pojave uobicajenih toksicnih efekata, nabrojanih u kriterijumima (Common Toxicity Criteria - CTC gradusa > 2) za akutne sporedne efekte. Zakljucak. Jednodozna SRS pomocu linearnog akcelatora bezbedna je i dobro podnosljiva terapijska procedura u lecenju bolesnika sa rekurentnim GB.