Postoperative adjuvant chemoradiotherapy in D2-dissected gastric cancer: Is radiotherapy necessary after D2-dissection?

Table 1 Major patient characteristics and results of phase III trials of postoperative radiotherapy for gastric cancer

Ref.	n	Enrolled period	Median F/u (m)	pT3-4	pN+	III-IV	D2	OS	DFS/RFS	Remarks
SWOG/INT-0116[3]	556	91-98	60	70%	85%	NR	10%	3-yr: 50% vs 41%(P = 0.005)	3-yr: 48% vs 31%(P < 0.001)	Similar benefit in 10-yr follow-up data
ARTIST[6]	458	04-08	53	NR	86%	41%	100%	NR	3-yr: 78% vs 74%(P = 0.0862)	DFS benefit in N+
NCC, South Korea[7]	90	02-06	87	63%	98%	100%	100%	5-yr: 65% vs 55%(P > 0.05)	5-yr: 61% vs 50%(P > 0.05)	LRRFS benefit(DFS benefit in stage III)
IMRT, China[8]	351	03-08	43	NR	86%	71%	Majority	5-yr: 48% vs 42%(P = 0.122)	5-yr: 45% vs 36%(P = 0.029)

F/u: Follow-up; PS: Performance status; NR: Not reported; OS: Overall survival; DFS/RFS: Disease-free survival/relapse-free survival; LRRFS: Loco-regional failure-free survival.

Table 2 Treatment parameters and toxicities in phase III studies of postoperative radiotherapy for gastric cancer

Ref.	Group	Concurrent chemo	RT planning	RT dose (Gy)	RT target	Severe toxicity	Completed planned treatment
SWOG/INT-0116[3]	CRT	5FU + LV	2D	45	Tumor bed, LN (Nos. 1-16)	G3+, 41%, G4+ 32%(GI, 33%)	64%(17 due to toxic effect)
ARTIST[6]	CT-CRT-CT	Capecitabine	2D or 3D	45	LN (Nos. 7-9 and 12-16)	Similar toxicity profile between the two groups (mostly well tolerated)	82% (5 due to toxic effect, but 1 during CRT)
NCC, South Korea[7]	CRT	5FU + LV	2D or 3D	45	Tumor bed, LN (Nos. 1-16)	G3+ Hema; 20% vs 25%, G3+ GI; 17% vs 11%	87% (2 due to toxic effect)
IMRT, China[8]	CRT	5FU + LV	IMRT	45	Tumor bed, LN (Nos. 1-16)	Similar toxicity profile between the two groups (mostly well tolerated)	91% (4 due to toxic effect)

RT: Radiotherapy; CRT: Chemo-radiotherapy; 5FU + LV: Fluorouracil and leucovorin; LN: Lymph node; GI: Gastrointestinal; Hema: Hematologic; IMRT: Intensity modulated radiotherapy.

Table 3 Description of lymph node station

LN station	Node location
1	LN at right paracardium
2	LN at left paracardium
3	LN along the lesser curvature
4	LN along the greater curvature
5	LN at suprapylorum
6	LN at infrapylorum
7	LN along the left gastric artery
8	LN along the common hepatic artery
9	LN around the celiac artery
10	LN at the splenic hilum
11	LN along the proximal splenic artery
12	LN in the hepatoduodenal ligament
12a	LN along the hepatic artery
12b	LN along the bile duct
12p	LN behind the portal vein
13	LN on the posterior surface of the pancreatic head
14	LN along the superior mesenteric vessels
15	LN along the middle colic vessels
16	LN around the abdominal aorta
16a	LN from the upper margin of the celiac trunk to the lower margin of the left renal vein
16b	LN from the upper margin of the left renal vein to the aortic bifurcation

LN: Lymph node.