Average dose-volume histogram (DVH) comparison for lung and heart with four different planning techniques.

6F-IMRT = six large fields IMRT plans with fixed jaw; 6F-IMRT-T = six large fields IMRT plans with jaw tracking technique; 12F-IMRT = twelve small fields IMRT plans with fixed jaw; 12F-IMRT-T = twelve small fields IMRT plans with jaw tracking technique.</p

The mean doses of organs at risk, MU, beam-on time, and mean dose rate (MDR) for treatment plans created with different planning techniques.

<p><i>Abbreviations:</i> HFF-VMAT-FF = two half-field full-arcs VMAT with conventional flattened (FF) beam; HFQ-VMAT-FF = eight half-field quarter-arcs VMAT with FF beam; HFQ-VMAT-FFF = eight half-field quarter-arcs VMAT with flattening filter free (FFF) beam.</p><p>* Body: it is the region of the CT which was scanned.</p><p>* <i>P</i> value corresponds to the paired <i>t</i> test: a = HFF-VMAT-FF vs HFQ-VMAT-FF, b = HFQ-VMAT-FF vs HFQ-VMAT-FFF.</p><p>The mean doses of organs at risk, MU, beam-on time, and mean dose rate (MDR) for treatment plans created with different planning techniques.</p

Planning Study of Flattening Filter Free Beams for Volumetric Modulated Arc Therapy in Squamous Cell Carcinoma of the Scalp - Figure 1

<p><b>Delineated planning target volume (PTV) for squamous cell carcinoma of the scalp (A), and two different beam setups in VMAT plans:</b> (B) Two 360° arcs were used with half-field beam. (C) Eight half-field quarter-arcs (90°) were used in VMAT plan.</p

Isodose distributions for one patient with esophageal cancer in four treatment plans.

6F-IMRT = six large fields IMRT plans with fixed jaw; 6F-IMRT-T = six large fields IMRT plans with jaw tracking technique; 12F-IMRT = twelve small fields IMRT plans with fixed jaw; 12F-IMRT-T = twelve small fields IMRT plans with jaw tracking technique.</p

The number of monitor units (MU), beam-on time (BOT), and mean dose rate (MDR) for treatment plans created with different planning techniques.

The number of monitor units (MU), beam-on time (BOT), and mean dose rate (MDR) for treatment plans created with different planning techniques.</p

Planning Study of Flattening Filter Free Beams for Volumetric Modulated Arc Therapy in Squamous Cell Carcinoma of the Scalp - Figure 2

<p><b>The beam setup of two designs for VMAT plans in clockwise (CW):</b> (A) HFF-VMAT: two half-field full-arcs VMAT; (B) HFQ-VMAT: eight half-field quarter-arcs VMAT.</p

Planning Study of Flattening Filter Free Beams for Volumetric Modulated Arc Therapy in Squamous Cell Carcinoma of the Scalp - Figure 4

<p><b>Dose-volume histogram (DVH) comparison for the PTV and brain with different planning techniques:</b> (a) HFF-VMAT-FF: two half-field full-arcs VMAT with conventional flattened (FF) beam; (b) HFQ-VMAT-FF: eight half-field quarter-arcs VMAT with FF beam; (c) HFQ-VMAT-FFF: eight half-field quarter-arcs VMAT with flattening filter free (FFF) beam.</p

Delineated planning target volume (PTV) for esophageal cancer in beam’s eye view (BEV) and jaw setup of IMRT plans.

(A) Jaw setup of large field IMRT plans. (B) Jaw setup of small field IMRT plans.</p

Dosimetric parameters comparison for the organs at risk: Total lung, heart, spinal cord, and spinal cord PRV.

Dosimetric parameters comparison for the organs at risk: Total lung, heart, spinal cord, and spinal cord PRV.</p

Dosimetric parameters comparison for PTV in four treatment plans.

Dosimetric parameters comparison for PTV in four treatment plans.</p