Prospective phase II trial of image-guided radiotherapy in Hodgkin lymphoma: Benefit of deep inspiration breath-hold

Figures & data

Figure 1. Volume receiving 20 Gy or more with free breathing (FB) and deep inspiration breath-hold (DIBH) in a patient treated with conventional parallel opposing fields (upper panel) and a patient treated with intensity-modulated radiotherapy (lower panel). These coronal views illustrate that the lung volume increases with DIBH and that the heart is pulled caudally with deep inspiration. This results in lower radiation doses to the lungs and heart.

Table I. Patient baseline and treatment characteristics.

Age (Median, range)
Years	30 (18–65)
Gender
Male	8
Female	14
Histological diagnosis
Nodular sclerosis	17
Mixed cellularity	4
Not specified	1
Clinical stage
CS 2A	16
CS 2B	6
WM
Yes	14
No	8
Courses of ABVD
6	6
4	10
3	2
2	4
Radiotherapy schedule
17 × 1.8 Gy	18
10 × 2 Gy	4
Response
CR	20
PD	2

CR, complete remission 8 weeks after completed radiotherapy; PD, progressive disease 8 weeks after completed radiotherapy; WM, involvement of whole mediastinum defined as extension of CTV ≥ 3 cm below carina on free breathing planning CT.

Table II. Dose characteristics with free breathing (FB) and deep inspiration breath-hold (DIBH).

	FB (median, range)		DIBH (median, range)		Difference (median, range)		p-Value*
Target
PTV volume (cm^3)	1198	(132, 1877)	945	(131, 1949)	62	(−361, 634)	0.07
CTV volume (cm^3)	213	(21, 511)	198	(14, 561)	3	(−126, 209)	0.60
PTV V95% (%)	94	(61, 98)	93	(78–97)	1	(−18, 7.4)	0.12
Lung
Lung volume (cm^3)	2924	(1908, 5228)	4936	(3391, 8776)	−2300	(−5272, −1093)	< 0.01
Mean lung dose (Gy)	8.5	(0.95, 18.9)	7.2	(1.0, 12.5)	2.0	(−0.08, 6.4)	< 0.01
Lung V20Gy (%)	14	(0, 46)	11	(0, 32)	5.3	(−1, 17)	< 0.01
Heart
Mean heart dose (Gy)	6.0	(0.12, 23)	3.9	(0.10, 17)	1.4	(0, 8.6)	< 0.01
Heart V20Gy (%)	15	(0.00, 76)	4.1	(0.00, 66)	6.3	(−2.7, 32)	< 0.01
Heart V30Gy (%)	2.0	(0.00, 35)	0.00	(0.00, 27)	0.8	(−7, 16)	0.01
Mean aortic valves dose (Gy)	26	(0.23, 31)	16	(0.20, 31)	1.9	(−1.8, 14)	< 0.01
Mean mitral valve dose (Gy)	7.1	(0.12, 30)	1.9	(0.10, 29)	0.58	(−1.3, 16)	< 0.01
Mean tricuspid valves dose (Gy)	2.6	(0.11, 30)	1.7	(0.10, 30)	0.43	(−4.6, 20)	0.01
Mean pulmonic valves dose (Gy)	26	(0.26, 32)	15	(0.23, 32)	1.4	(−1.9, 21)	< 0.01
Mean LAD dose (Gy)	8.9	(0.10, 29)	5.0	(0.09, 27)	0.80	(−1.8, 14)	< 0.01
Mean LMA dose (Gy)	25	(0.25, 32)	18	(0.20, 32)	3.0	(−11, 21)	< 0.01
Mean LC dose (Gy)	11	(0.18, 31)	7.7	(0.15, 31)	0.40	(−4.0, 25)	0.02
Mean RCA dose (Gy)	27	(0.16, 31)	17	(0.01, 32)	0.29	(−17, 24)	0.06
Breast
Mean dose right breast (Gy)	5.0	(0.11, 15)	6.4	(0.074, 13)	0.00	(−4.8, 2.2)	0.47
Mean dose left breast (Gy)	3.7	(0.11, 15)	3.2	(0.090, 13)	0.01	(−3.6, 6.8)	0.22

CTV, clinical target volume; LAD, left anterior descending coronary artery; LC, left circumflex coronary artery; LMA, left main coronary artery; PTV, planning target volume; PTV V_95%, percentage of PTV receiving at least 95% of the specified radiation dose; RCA, right coronary artery; V_20Gy, percentage of organ receiving ≥ 20 Gy; V_30Gy, percentage of organ receiving ≥ 30 Gy.*Wilcoxon's signed rank test.

Figure 2. Mean heart dose (left) and heart volume receiving 20 Gy or more in the individual patients with free breathing (FB) and deep inspiration breath-hold (DIBH). Patients with disease in the upper mediastinum, meaning extension < 3 cm below carina, are represented with solid black lines and patients with disease in the whole mediastinum meaning extension ≥ 3 cm below carina are represented with blue dotted lines. Note that some patients received no dose to the heart in FB or in DIBH. DIBH, deep inspiration breath-hold; FB, free breathing; V20Gy, volume receiving 20 Gy or more.

Figure 3. Dose-volume histogram showing the average dose to a certain proportion of heart volume (left) and lung volume (right). DIBH, deep inspiration breath-hold; FB, free breathing.