Analysis of the Dose Drop at the Edge of the Target Area in Heavy Ion Radiotherapy

Table 1

Dose decay data at the end edge of beam.

Parameters of TPS			Dose decay percentage at the end edge of beam (at a specified distance: mm)
Beam setup	Fractions	Dose/Fx Gy (RBE)	1 mm	2 mm	3 mm	4 mm	5 mm	10 mm	15 mm	20 mm
Single direction beam	20	3	86.43%	66.10%	45.78%	25.46%	18.84%	16.95%	15.51%	14.13%
	15	4	81.81%	61.87%	41.93%	24.20%	19.95%	17.98%	16.49%	15.03%
	10	6	91.60%	72.17%	52.73%	33.29%	22.52%	20.20%	18.52%	16.94%
	6	10	84.22%	65.69%	47.16%	29.81%	25.43%	23.07%	21.24%	19.45%
Two-beam irradiation in opposite direction	20	3	92.13%	78.75%	65.37%	51.99%	45.93%	41.30%	38.00%	35.41%
	15	4	91.66%	78.57%	65.47%	52.38%	47.02%	42.40%	39.10%	36.49%
	10	6	93.27%	80.69%	68.11%	55.53%	49.14%	44.52%	41.18%	38.52%
	6	10	88.25%	76.49%	64.74%	54.45%	52.07%	47.60%	44.31%	41.65%
Horizontal and vertical (horizontal beam)	20	3	90.88%	76.16%	61.43%	46.91%	36.62%	9.93%	7.34%	6.68%
	15	4	91.36%	76.79%	62.22%	47.66%	37.40%	10.27%	7.63%	6.94%
	10	6	91.18%	76.92%	62.65%	48.58%	38.29%	10.83%	8.13%	7.41%
	6	10	86.01%	72.03%	58.04%	45.04%	36.75%	11.45%	9.03%	8.24%
Horizontal and vertical (vertical beam)	20	3	86.30%	70.17%	54.04%	37.96%	30.34%	10.16%	7.54%	6.88%
	15	4	83.90%	67.80%	51.70%	35.76%	29.88%	10.34%	7.83%	7.16%
	10	6	85.38%	69.57%	53.77%	38.71%	31.18%	10.96%	8.31%	7.60%
	6	10	84.35%	68.70%	53.06%	38.22%	32.06%	11.88%	9.24%	7.62%