Adjuvant radiotherapy for gallbladder cancer: A dosimetric comparison of conformal radiotherapy and intensity-modulated radiotherapy

Table 1 Patient and tumor characteristics (n = 20)

Characteristics	n (%)
Median age (range, yr)	56 (33-73)
Gender
Male	8 (40)
Female	12 (60)
ECOG performance status
0	2 (10)
1	16 (80)
2	2 (10)
Tumor and node status
PT1	0 (0)
PT2	13 (65)
PT3	6 (30)
PT4	1 (5)
NX
PN0	13 (65)
PN	7 (35)
Tumor grade
Well	8 (40)
Moderate	9 (45)
Poor	3 (15)

ECOG: Eastern Cooperative Oncology Group; NX: Node staging.

Table 2 Treatment details for the patients

Treatment	No. of patients
CT concurrent RT	9
5-fluorouracil	4
Oxaliplatin	5
Concurrent RT followed by CT	7
5-fluorouracil + oxaliplatin	4
Gemcitabine + oxaliplatin	3
RT followed by CT	3
5-fluorouracil + oxaliplatin	1
Gemcitabine + oxaliplatin	2
Postoperative CT before RT	2
5-fluorouracil bolus
RT alone	6

Nine patients received concurrent radiochemotherapy, 7 of them received adjuvant chemotherapy. CT: Chemotherapy; RT: Radiotherapy.

Table 3 Mean dose to the targeted structures/organs

Structure/organs	Mean dose (Gy)		P value1
	CRT	IMRT
PTV	50.1 ± 2.8	51.5 ± 2.7	0.00015
Right kidney	10.6 ± 4.4	8.6 ± 2.4	0.032
Left kidney	8.1 ± 3.4	9.4 ± 4.6	NS
Liver	22.4 ± 3.9	21.0 ± 2.9	0.027

¹Two-tailed paired t test. Values are expressed as mean ± SD. CRT: Three dimensional conformal radiation therapy; IMRT: Intensity-modulated radiation therapy; PTV: Planning tumor volume; NS: Not significant (P > 0.05).

Table 4 Volume of structures/organs receiving greater than the threshold dose

Structure/organs	Dose (Gy)	Volume above threshold dose (%)		P value1
		CRT	IMRT
PTV	95% of prescribed dose	84.0 ± 6.7	82.9 ± 6.1	NS
Organs at risk
Right kidney	20.0	12.5 ± 11.7	5.4 ± 2.7	0.031
Left kidney	20.0	5.3 ± 6.0	3.7 ± 2.3	NS
Liver	30.0	34.5 ± 8.0	30.1 ± 6.3	0.0065

¹Two-tailed paired t test. Values are expressed as mean ± SD. CRT: Three dimensional conformal radiation therapy; IMRT: Intensity-modulated radiation therapy; PTV: Planning tumor volume; NS: Not significant (P > 0.05).