The effect on esophagus after different radiotherapy techniques for early stage Hodgkin's lymphoma

Figures & data

Table I. Patient characteristics.

	Number (%)
Patients	46
Gender
Male	24 (52)
Female	22 (48)
Age
Years, median (range)	33.5 (15–76)
Histology
NS	33 (72)
MC	11 (24)
Classical, NOS	2 (4)
Clinical stage
IA	2 (4)
IIA	28 (61)
IIAE	1 (2)
IIB	15 (33)
EORTC prognostic group
Favorable	16 (35)
Unfavorable	30 (65)
PS
0	38 (83)
1	8 (17)
Chemotherapy
ABVD	43 (94)
ABVD/BEACOPP^1	2 (4)
ChlVPP^2	1 (2)
Number of cycles
2	8 (18)
3	6 (13)
4	20 (43)
6	11 (24)
8^3	1 (2)
RT
With boost^4	37 (80)
Without boost	9 (20)
AP/PA	43 (93)
IMRT^5	3 (7)
RT toxicity^6
Grade 0	28 (61)
Grade 1	8 (17)
Grade 2	10 (22)

ABVD, adriamycin, bleomycin, vinblastine, dacarbazine; AP/PA, anteriorposterior/posterioranterior; BEACOPP, bleomycin, etoposid, adriamycin, cyclophosphamide, vincristine, procarbazine, prednisone; ChlVPP, chlorambucil, vinblastine, procarbazine, prednisone; EORTC, European Organization for Research and Treatment of Cancer; IMRT, intensity modulated radiotherapy; NOS, not otherwise specified; NS, nodular sclerosis; MC, mixed cellularity; PS, Performance status according to WHO; RT, radiotherapy.

¹Patients in EORTC-Group d'Etudes des Lymphomes de l'Adulte-, Intergruppo Italiano linifomi (EORTC-GELA-IIL) H10 protocol, experimental arm; ²Patient, 75 years old with chronic heart failure and poor lung function; 3Patient with CS2B, bulky tumor and risk factors (complete metabolic response after 4 cycles); ⁴Patients with partial response after chemotherapy were given a boost of 1.8 Gy × 3.5 fractions per week to lymph node remnants; ⁵Three patients received IMRT to limit radiation dose to the lungs; ⁶RT toxicity was graded retrospectively from patient charts according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Main complications were redness of skin, soreness of throat and light pain.

Figure 1. Treatment plans with 3DCRT, VMAT, PT and MF for one patient shown in dose color wash. The esophagus is delinated in blue.

Figure 2. Minimum, mean and maximum dose distribution to the esophagus with 3DCRT, VMAT, PT and MF treatment. Boxes represent the 25th to 75th percentiles; whiskers represent the range, the plus signs represent outliers.

Table II. Mean, maximum and minimum dose to the esophagus with 3DCRT, VMAT, PT and MF treatment plans without outliers and p-values for all comparisons and their pair-wise comparisons. Doses are reported as median values for the whole group.

	Dose to the esophagus (range), Gy
	Mean dose	Maximum dose	Minimum dose
RT techniques
3DCRT	16.4 (0.71–25.7)	31.4 (5.25–33.6)	0.35 (0–3.85)
VMAT	16.4 (4.54–25.4)	31.8 (14.5–33.8)	0.40 (0–5.75)
PT	14.7 (0.08–24.9)	31.7 (3.95–33.1)	10^−9 (10^−9)
MF	34.2 (27.3–35.9)	39.6 (37.2–42.5)	29.1 (4.00–32.3)
All comparisons	p < 0.001	p < 0.001	p < 0.001
Pair-wise comparisons^1
3DCRT vs. VMAT	p = 1.000	p = 0.266	p = 0.020
3DCRT vs. PT	p = 0.001	p = 1.000	p < 0.001
VMAT vs. PT	p < 0.001	p = 0.463	p < 0.001
3DCRT vs. MF	p < 0.001	p < 0.001	p < 0.001
VMAT vs. MF	p < 0.001	p < 0.001	p < 0.001
PT vs. MF	p < 0.001	p < 0.001	p < 0.001

MF, mantle field; PT, proton therapy; 3DCRT, three-dimensional conformal radiotherapy; VMAT, volumetric modulated arc therapy.

¹Adjustment for multiple comparisons: Bonferroni.

Table III. Risk estimates with 3DCRT, VMAT, PT and MF treatment plans and p-values for all comparisons and their pair-wise comparisons.

	Risk estimates (range),%
	Esophagitis	Esophageal stricture	Esophageal cancer
RT techniques
3DCRT	4.31 (0.28–11.6)	0.006 (0–0.29)	0.14 (0–0.90)
VMAT	4.22 (0.28–11.3)	0.005 (0–0.26)	0.16 (0–0.89)
PT	3.68 (0.27–11.0)	0.003 (0–0.24)	0.12 (0–0.87)
MF	22.6 (13.9–25.7)	2.39 (0.55–3.43)	1.02 (0.21–1.24)
All comparisons	p < 0.001	p < 0.001	p < 0.001
Pair-wise comparisons^1
3DCRT vs. VMAT	p = 1.000	p = 1.000	p = 0.356
3DCRT vs. PT	p = 0.003	p = 0.066	p = 0.008
VMAT vs. PT	p < 0.001	p = 0.002	p < 0.001
3DCRT vs MF	p < 0.001	p < 0.001	p < 0.001
VMAT vs. MF	p < 0.001	p < 0.001	p < 0.001
PT vs. MF	p < 0.001	p < 0.001	p < 0.001

MF, mantle field; PT, proton therapy; 3DCRT, three-dimensional conformal radiotherapy; VMAT, volumetric modulated arc therapy.

¹Adjustment for multiple comparisons: Bonferroni.