TABLE 5.
A summary of the measurement results for the TG 119, single brain metastasis, and pelvis IMRT plans in Solid Water (film and PinPoint ionization chamber)
| PinPoint chamber | Film | ||||
|---|---|---|---|---|---|
| Plan | Location | %diff* | Location | γ 3%/2 mm | ArcCHECK® γ 3%/2 mm |
| TG119 Prostate IMRT | High dose/low gradient | 0.4% | 2.5 cm POST/low dose | 99.8% | 100.0% |
| TG119 HN IMRT | High dose/low gradient | −0.4% | 4 cm POST/low dose | 95.6% | 99.3% |
| TG119 CShape Easy IMRT | Low dose/high gradient | −2.6% | 2 cm ANT/high dose | 94.6% | 98.1% |
| TG119 CShape Hard IMRT | Low dose/high gradient | −2.4% | 2 cm ANT/high dose | 97.2% | 98.1% |
| Pelvis IMRT | High dose/low gradient | 2.2% | 2.5 cm POST/low dose | 95.3% | 97.7% |
| Brain Met (d = 1.5 cm) SBRT | High dose/high gradient | 7.9% | iso/high dose | 100% | 93.4% |
| Brain Met (d = 2.0 cm) SBRT | High dose/low gradient | 0.6% | iso/high dose | 96.9% | 93.0% |
| Brain Met (d = 3.0 cm) SBRT | High dose/low gradient | 0.0% | iso/high dose | 96.2% | 93.7% |
| Mean | 0.7% | 97.0% | 96.7% | ||
| σ | 3.1% | 1.9% | 2.8% | ||
The same plans were also recalculated and delivered to the Sun Nuclear ArcCHECK®. The film and ArcCHECK® measured doses were compared to the planned doses using a Gamma analysis with criteria of 3%/2 mm. The percent difference (relative to the prescription dose) was calculated between the PinPoint‐measured dose and the TPS‐reported mean dose to the sensitive air volume of the chamber.