Regional Variation across Canadian Centers in Radioiodine Administration for Thyroid Remnant Ablation in Well-Differentiated Thyroid Cancer Diagnosed in 2000–2010

Table 4

Percentage of patients receiving RAI over time (all centers combined).

Year of diagnosis	TNM stage								Overall by year
	T1		T2		T3		T4
	N1a/N1b	N0/Nx	N1a/N1b	N0/Nx	N1a/N1b	N0/Nx	N1a/N1b	N0/Nx
2000	80%	43%	100%	48%	71%	59%	33%	50%	51%
2001	70%	35%	100%	60%	83%	44%	71%	100%	55%
2002	82%	49%	100%	74%	89%	57%	67%	67%	64%
2003	69%	54%	100%	78%	88%	93%	50%	67%	71%
2004	77%	57%	100%	82%	90%	91%	100%	N/A	73%
2005	83%	73%	75%	91%	89%	91%	75%	100%	82%
2006	78%	61%	93%	84%	90%	88%	N/A	50%	75%
2007	100%	52%	90%	77%	95%	82%	50%	100%	71%
2008	76%	45%	83%	71%	91%	88%	78%	100%	67%
2009	100%	36%	87%	66%	94%	84%	100%	100%	60%
2010	60%	28%	69%	61%	75%	69%	86%	100%	51%
P-trend (2000–2010)	NS	<0.01	0.03	NS	NS	0.045	NS	NS	0.03
P-trend (2006–2010)	NS	<0.01	NS	<0.01	0.03	0.04	NS	NS	<0.01
Overall by stage	79%		86%	73%	88%	80%	76%	83%

Data are presented as % per year, with the percentage referring to fraction of patients receiving RAI.
Trend analysis was done to compare fraction of patients receiving RAI for each TN stage over time. Only two centers (London and Winnipeg) included patients before 2006; therefore, a separate trend analysis was performed for 2006–2010.
compared to N1a/N1b group; NS: nonsignificant.