Feasibility Study of the Simultaneous Integrated Boost (SIB) Method for Malignant Gliomas Using Intensity-modulated Radiotherapy (IMRT)

Abstract

The treatment of 70 Gy/28 fr/daily 2.5 Gy to the GTV and 56 Gy/28 fr/daily 2.0 Gy to the CTV-a was feasible both physically and clinically.

Treatment outcomes and dose-volume histogram analysis of simultaneous integrated boost method for malignant gliomas using intensity-modulated radiotherapy

“…We have already reported the details of the target volume delineation in this clinical trial, in which the contouring of PTV-G and PTV-a was graphically demonstrated. 6,12 Treatment planning A commercial treatment-planning system (Cadplan Helios ver.6.01; Varian Associates, Palo Alto, CA, USA) was used. The IMRT beam arrangements consisted of fi ve coplanar beams.…”

“…Details of the quality assurances (QA) in the present study have been described in our previous report. 6 Chemotherapy Eleven of the 13 patients received one or two courses of nimustine hydrochloride (ACNU) (100 mg/m 2 ) and vincristine (1.2 mg/body) and interferon-β (3 × 10 6 units) three times weekly during the radiotherapy. Adjuvant chemotherapy, ACNU (100 mg/m 2 ) and vincristine (1.2 mg/body), was repeated every 6 weeks and interferon-β was repeated every 2 weeks.…”

“…Our initial experience with six patients showed local recurrence in fi ve patients within 7 months of the start of radiotherapy, although, concerning dosimetry and early toxicity, the feasibility of our protocol was confi rmed. 6 The clinical outcomes of SIB-IMRT for malignant glioma have been reported. [7][8][9][10] In a study reported by Iuchi et al, 7 the following hypofractionation regimen was used; in 8 fractions, 48-68 Gy was delivered to the area of enhancing lesion with a 5-mm margin, 40 Gy was delivered to the area with a 15-mm margin, and 32 Gy was delivered to the area of the peritumoral edema.…”

Interpretation of Gamma Index for Quality Assurance of Simultaneously Integrated Boost (SIB) IMRT Plans for Head and Neck Carcinoma

“…Mohan et al [4] introduced the concept of SIB IMRT: Advantageous technique in terms of better conformity to target, shorter treatment time, better dose hotspot control and reduced exposure of radiations to Organs at Risk (OARs) such as parotids, spinal cords, optic nerve, optic chaisma, brain stem, and oral cavity [3][4]. This technique is specifically found useful for head and neck carcinoma due to histologically heterogeneous nature of tumor and low dose radiation tolerance to normal surrounding tissues [5][6]. To achieve local control of disease, high dose of radiation in the range of 70 Gy is required in the treatment of head and neck cancer [1].…”

Novel Anisotropic Margin Calculation Based On the Cumulative Frequency Distribution of Uncertainties in the Clinical Target Volume

“…To verify leaf motion of each beam or specific patient's plans, various quality assurance tests were conducted [8,9]. Once the VMAT plan was developed and approved, CT simulation datasets were imported into the ExacTrac® X-ray 6D system (BrainLab AG, Feldkirchen, Germany) for 2D/3D registration using digital reconstructed radiographs (DRRs) of 2D oblique images to the planning CT images [10].…”