Target delineation in high-grade glioma do CTV margins make a difference? ESTRO ACROP versus RTOG guidelines a comparative dosimetric study

Bindhu Joseph, Vishal Malavade, Nisarga V M, Vijay C R, Ramesh C, Lokesh Vishwanath

Abstract


Background and purpose: There exist two major consensus guidelines for target delineation in glioblastoma (GBM). Namely the established radiation therapy oncology group (RTOG) and the recently redefined European society for radiation oncology (EORTC)-advisory committee on radiation oncology practice (ACROP). Clinical studies evaluating the pattern of recurrence with relation to the CTV margins have as of date not evidenced statistically significant difference in relation to the two guidelines. However, considering the standardization of concurrent chemo-radiation with Temozolomide nearly 20% off patients can be expected to survive 2years or beyond. Quality of life issues will play a higher role in defining the better protocol. In the current study, we have dosimetrically compared these guidelines in both perspectives. Material and methods: Thirty patients of GBM who had been planned for conformal radiotherapy from Jan 2017 to Feb 2019 were considered. Each patient dataset contoured with ESTRO-ACROP guidelines to create PLAN A and RTOG guidelines to create PLAN B. Both plans were compared to evaluate the volumetric difference in terms of PTV and the relative proximity to critical normal structures. Results: The median volume of brain irradiated to high doses (60Gy) was significantly greater in PLAN B, 566cc vs 398 ccs (p<0.0002). The organs at risk were better spared with PLAN A in terms of encroachment of high dose PTV volume. This achieved significance for Brainstem (p<0.01), Chiasma (p<0.04) and hippocampus (p<0. 016). We were able to identify patients with PTV volume >400cc and with tumor in Parietal or Temporal regions wouldn’t benefit from PLAN A. Conclusion: The use of target delineation based on a single step plan, excluding expanded edema (ESTRO-ACROP) could potentially reduce high dose target volumes and significantly spare brainstem, optic-chiasma, and hippocampus. Patients with tumor volume <400 cc and frontal lesions are most likely to benefit.

Keywords


Glioblastoma; Peritumoral edema; Contouring guidelines; Organs at risk.

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References


Stupp R, Mason WP, van den Bent MJ, et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. N Engl J Med. 2005;352(10):987–996.

Walker MD, Alexander E Jr, Hunt WE, et al. Evaluation of BCNU and/or radiotherapy in the treatment of anaplastic gliomas. A cooperative clinical trial. J Neurosurg. 1978;49(3):333–343.

Kristiansen K, Hagen S, Kollevold T, et al. Combined modality therapy of operated astrocytomas grade III and IV. Confirmation of the value of postoperative irradiation and lack of potentiation of bleomycin on survival time: a prospective multicenter trial of the Scandinavian Glioblastoma Study Group. Cancer 1981;47:649–52.

Laperriere N, Zuraw L, Cairncross G. Radiotherapy for newly diagnosed malignant glioma in adults: a systematic review. RadiotherOncol 2002;64:259–73.

Eric H, Han S, Catherine C. The evolving roles and controversies of radiotherapy in the treatment of glioblastoma. J Med RadiatSci 2016;63;114–123.

Lawrence YR, Li XA, el Naqa I, et al. Radiation dose–volume effects in the brain. Int J RadiatOncolBiolPhys 2010;76:S20–7.

Walker MD, Alexander Jr E, Hunt WE, et al. Evaluation of BCNU and/or radiotherapy in the treatment of anaplastic gliomas. A cooperative clinical trial. J Neurosurg 1978;49:333–43.

Walker MD, Green SB, Byar DP, et al. Randomized comparisons of radiotherapy and nitrosoureas for the treatment of malignant glioma after surgery. N Engl J Med 1980;303:1323–9.

Walker MD, Strike TA, Sheline GE. An analysis of dose–effect relationship in the radiotherapy of malignant gliomas. Int J RadiatOncolBiolPhys 1979;5:1725–31.

Stupp R, Hegi ME, Mason WP, et al. Effects of radiotherapy with concomitant and adjuvant temozolomide versus radiotherapy alone on survival in glioblastoma in a randomised phase III study: 5-year analysis of the EORTCNCIC trial. Lancet Oncol 2009;10:459–66.

Stupp R, Mason WP, van den Bent MJ, et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. N Engl J Med 2005;352:987–96.

Corn BW, Wang M, Fox S, et al. Health related quality of life and cognitive status in patients with glioblastomamultiforme receiving escalating doses of conformal three dimensional radiation on RTOG 98–03. J Neurooncol 2009;95:247–57.

Scheibel RS, Meyers CA, Levin VA. Cognitive dysfunction following surgery for intracerebralglioma: influence of histopathology, lesion location, and treatment. J Neurooncol 1996;30:61–9.

Halperin EC, Bentel G, Heinz ER, Burger PC. Radiation therapy treatment planning in supratentorialglioblastomamultiforme: an analysis based on post mortem topographic anatomy with CT correlations. Int J RadiatOncolBiol Phys. 1989;17(6):1347–1350.

Schoenegger K, Oberndorfer S, Wuschitz B, et al. Peritumoral edema on MRI at initial diagnosis: an independent prognostic factor for glioblastoma? Eur J Neurol. 2009;16(7):874–878.

Pope WB, Sayre J, Perlina A, Villablanca JP, Mischel PS, Cloughesy TF. MR imaging correlates of survival in patients with high-grade gliomas. AJNR Am J Neuroradiol. 2005;26(10):2466–2474.

Iliadis G, Kotoula V, Chatzisotiriou A, et al. Volumetric and MGMT parameters in glioblastoma patients: survival analysis. BMC Cancer. 2012;12:3.

Oppitz U, Maessen D, Zunterer H, Richter S, Flentje M. 3D-recurrence-patterns of glioblastomas after CT-planned postoperative irradiation. RadiotherOncol. 1999;53(1):53–57.

Minniti G, Amelio D, Amichetti M, et al. Patterns of failure and comparison of different target volume delineations in patients with glioblastoma treated with conformal radiotherapy plus concomitant and adjuvant temozolomide. RadiotherOncol. 2010;97(3):377–381




DOI: http://dx.doi.org/10.30564/amor.v4i6.206

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