Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Descriptions of the analysis methods used to help identify the errors.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques: Comparison, Generated

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Absolute dose planes at 10 cm depth, 100 cm source-detector-distance (SDD) shown for (a) measured and (b) calculated dose. (c) 3%G/3 mm gamma failing points. (d) Dose profiles, dots represent calibrated diode measurements and solid lines the interpolated TPS profiles and (e) with measured profile (dotted) up-sampled using a commercial method (Refs. 12 and 13, and 34). (f) Patient sagittal planar dose from TPS and (g) with 3DVH-esimated error showing lower estimated patient dose as dose difference, and (h) as shifts in DVH curves for two target volumes.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques:

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Absolute dose planes at 5 cm depth, 100 cm SDD for (a) measured and (b) calculated dose. (c) 3%G/3 mm gamma with failing points shown as the shaded region over the calculated plane in grayscale. (d) 2%L/2 mm gamma failing points showing a clear pattern of meas < calc, i.e., shaded regions showing gamma failing points. (e) Patient coronal TPS plane, (f) 3DVH-estimated dose differences (3DVH–TPS), and (g) estimated DVH errors showing lower MGDR target dose compared to planned.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques:

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Passing rate method (per beam planar or composite), dosimeters, and analysis methods employed for each case study.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques: Diagnostic Assay

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Two-arc VMAT plan. (a) 3%G/3 mm gamma failing points on the ArcCHECK detector surface and (b) the same data highlighting points failing 2%L/2 mm gamma analysis. (c) Gamma histogram generated for the same plan using a different 3D dosimeter (Delta4) showing the 94.7% passing rate and (d) absolute dose profiles in the Delta4 illustrating meas < calc over the entire high dose region. (e) TPS dose distribution and (F) 3D MGDR reconstructed dose vs TPS dose for a sagittal plane through the high dose region, showing the clear bias of meas < calc as the shaded region.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques: Generated

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Passing rate method (per beam planar or composite), dosimeters, and analysis methods employed for each case study.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques: Diagnostic Assay

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Case Study A (top): Seven-beam IMRT plan. (a) 3%G/3 mm gamma failing points over the ArcCHECK detector surface and (b) the same data highlighting points failing 2%L/2 mm gamma analysis. In panels (a) and (b), the visible dots represent failing points. (c) Dose profile over the central (Y = 0 mm) quasi-circular circumference of detectors (location of profile shown by the horizontal line in panel (a) showing meas > calc in peaks and meas < calc in valleys of dose, with the black line a profile interpolated through the TPS dose grid and the dots representing dose measured by the point detectors. (d) 3D MGDR reconstructed dose vs TPS dose for central axial plane, showing points failing 3%G/3 mm gamma analysis, and (e) the same data analyzed with 2%L/2 mm which introduces sensitivity enough to highlight the dose gradient differences. In panels (d) and (e), shaded regions indicate MGDR > calc or MGDR < calc. (f) Dose profile through the horizontal line indicated with arrows in panel (a), also showing the dose gradient differences, with the solid line representing the TPS dose and dotted line the reconstructed measurement. (b) Case Study B: The same TPS model as Case Study A of Fig. 4 analyzed for a single arc VMAT plan. (a) 3%G/3 mm gamma failing points over the ArcCHECK detector surface and (b) the same data highlighting points failing 2%L/2 mm gamma analysis. In panels (a) and (b), the visible dots represent failing points. (c) 3D MGDR reconstructed dose vs TPS dose for central axial plane, showing points failing 3%G/3 mm gamma analysis and (d) the same data analyzed with 2%L/2 mm which introduces sensitivity high enough to highlight the dose gradient differences. (e) Dose profile through the horizontal line indicated with arrows in panel (a), also showing the dose gradient differences, with the black line the TPS dose and dotted line the reconstructed measurement.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques:

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Two-arc VMAT plan. (a) 3%G/3 mm gamma failing points on the ArcCHECK detector surface and (b) the same data highlighting points failing 2%L/2 mm gamma analysis. (c) Gamma histogram generated for the same plan using a different 3D dosimeter (Delta4) showing the 94.7% passing rate and (d) absolute dose profiles in the Delta4 illustrating meas < calc over the entire high dose region. (e) TPS dose distribution and (F) 3D MGDR reconstructed dose vs TPS dose for a sagittal plane through the high dose region, showing the clear bias of meas < calc as the shaded region.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques: Generated

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: An open 10 × 10 cm2 beam incident on a homogeneous PMMA cylindrical phantom. (a) 3%G/3 mm gamma failing points over the ArcCHECK detector surface and (b) the same data highlighting points failing 2%L/2 mm gamma analysis, where now the meas < calc bias at the beam exit surface becomes visually evident. (c) 3D MGDR reconstructed dose vs TPS dose for central axial plane, showing points failing 2%L/2 mm gamma analysis confirming the meas < calc trend that increases with depth, and (d) the central axis depth dose profiles of TPS (black line) vs MGDR (two-tone shaded line that is below the TPS depth dose line).

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques:

Journal: Medical Physics

Article Title: Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

doi: 10.1118/1.4826166

Figure Lengend Snippet: Two-arc VMAT plan delivered on a uniform cylindrical phantom. (a) 3%G/3 mm gamma failing points over the ArcCHECK detector surface and (b) the same data highlighting points failing 2%L/2 mm gamma analysis, where now a trend is visualized where meas > calc on the left side of the phantom and meas < calc on the right side, as indicated by shaded regions. (c) 3D MGDR reconstructed dose vs TPS dose for central axial plane, showing points failing 3%G/3 mm gamma analysis showing 100% passing rate, then (d) reanalyzed using 2%L/2 mm confirming the clear error pattern. (e) Analysis of the virtual phantom geometry in the TPS confirms that the beam isocenter was not centered in the phantom model but rather was shifted about 2.75 mm laterally.

Article Snippet: Specific tools included MapCHECK, MapCHECK2, EPIDose, ArcCHECK, and 3DVH (Sun Nuclear Corporation, Melbourne, FL) and Delta4 (Scandidos AB, Uppsala, Sweden).

Techniques: