Algorithms to identify radiotherapy intent in unresected non-metastatic non-small-cell lung cancer: an I-O Optimise analysis

Figures & data

Table 1. Overview of the RT data available at IPO-Porto and REAL-Oncology.

Variable	Format	IPO-Porto	REAL-Oncology
RT administration date	DD/MM/YYYY	Available in IPO-Porto's specific RT database	Available in hospital-specific RT system (MOSAIQ)
RT type	SBRT, EBRT, etc.	Available as structured data in EMR	Not available as structured data^†
Dose per administration	In Gy	Not available as structured data in EMR^†	Available in hospital-specific RT system (MOSAIQ)

† Information may be available for some patients in free text notes.

EBRT: External beam radiotherapy; EMR: Electronic medical record; Gy: Gray unit of ionizing radiation; RT: Radiotherapy; SBRT: Stereotactic body radiotherapy.

Figure 1. Initial treatment categories.

RT: Radiotherapy; SACT: Systemic anticancer therapy.

Table 2. Summary of algorithm development and validation.

Algorithm	Patients	Treatment	IPO-Porto	REAL-Oncology
Algorithm #1	All stages	RT alone & RT + SACT	D + T	V
	Stage I–II vs IIIA vs IIIB	RT + SACT
Algorithm #2	All stages	RT alone & RT + SACT	D + T	–
Algorithm #3	All stages	RT alone & RT + SACT	–	D + T

D: Developed; RT: Radiotherapy; SACT: Systemic anticancer therapy; T: Tested; V: Validated.

Figure 2. Algorithms developed to assess RT intent classification based on RT duration alone (A), RT duration and type (B), or RT dose (C).

Gy: Gray unit of ionizing radiation; RT: Radiotherapy; SBRT: Stereotactic body radiotherapy.

Table 3. Baseline demographics and clinical characteristics of base population by initial treatment and data source.

		RT alone				RT + SACT
		IPO-Porto		REAL-Oncology		IPO-Porto		REAL-Oncology
		N = 47		N = 716		N = 119		N = 277
Characteristics		n	%	n	%	n	%	n	%
Year of diagnosis	2007	–	–	31	4.3	–	–	25	9.0
	2008	–	–	31	4.3	–	–	20	7.2
	2009	–	–	57	8.0	–	–	17	6.1
	2010	–	–	44	6.1	–	–	22	7.9
	2011	–	–	72	10.1	–	–	23	8.3
	2012	–	–	71	9.9	–	–	22	7.9
	2013	–	–	65	9.1	–	–	24	8.7
	2014	–	–	62	8.7	–	–	24	8.7
	2015	9	19.1	65	9.1	43	36.1	35	12.6
	2016	16	34.0	79	11.0	31	26.1	23	8.3
	2017	16	34.0	73	10.2	37	31.1	22	7.9
	2018	6	12.8	66	9.2	8	6.7	20	7.2
Age at NSCLC diagnosis, years	<65	10	21.3	73	10.2	64	53.8	122	44.0
	65–74	18	38.3	218	30.4	42	35.3	112	40.4
	≥75	19	40.4	425	59.4	13	10.9	43	15.5
Sex	Female	11	23.4	374	52.2	17	14.3	123	44.4
	Male	36	76.6	342	47.8	102	85.7	154	55.6
TNM classification at diagnosis	I	39	83.0	332	46.4	M	M	12	4.3
	II	M	M	149	20.8	26	21.8	44	15.9
	IIIA	M	M	150	20.9	58	48.7	122	44.0
	IIIB	M	M	85	11.9	31	26.1	99	35.7
Histology	Non-squamous	34	72.3	120	16.8	55	46.2	84	30.3
	Squamous	13	27.7	213	29.7	61	51.3	133	48.0
	NSCLC-NOS	M	M	74	10.3	M	M	46	16.6
	Other miscellaneous NSCLC^†	M	M	8	1.1	M	M	M	M
	Clinically diagnosed	–	–	301	42.0	–	–	M	M

To comply with patient confidentiality requirements, data outputs relating to groups of fewer than five patients were masked (M). In some circumstances, data relating to larger patient subgroups were also masked to avoid extrapolation of counts of fewer than five patients.

† Includes large cell carcinoma with rhabdoid phenotype; sarcomatoid carcinoma, pleomorphic; NUT carcinoma; spindle cell and giant cell carcinoma; giant cell carcinoma; spindle cell carcinoma, NOS; pseudosarcomatous carcinoma; basaloid carcinoma; adenocystic carcinoma; mucoepidermoid carcinoma; adenosquamous carcinoma; epithelial-myoepithelial carcinoma; blastoma, pulmonary (pneumoblastoma); carcinosarcoma, NOS; and myoepithelial carcinoma.

M: Masked; NOS: Not otherwise specified; NSCLC: Non-small-cell lung cancer; RT: Radiotherapy; SACT: Systemic anticancer therapy; TNM: Tumor, node, metastasis.

Table 4. Overall accuracy of correctly predicting RT intent per algorithm.

	Algorithm #1				Algorithm #2		Algorithm #3
	IPO-Porto		REAL-Oncology		IPO-Porto		REAL-Oncology
	N	Accuracy (%)	N	Accuracy (%)	N	Accuracy (%)	N	Accuracy (%)
Treatment modalities
RT alone	47	19.1	681	54.5	47	100	714	99.2
RT + SACT	119	99.2	272	91.1	119	100	277	98.6
Stage at diagnosis
RT + SACT
Stage I–II	30	96.7	55	89.1	–		–
Stage IIIA	58	100	120	90.0	–		–
Stage IIIB	31	100	99	93.8	–		–

RT: Radiotherapy; SACT: Systemic anticancer therapy.

Table 5. Detailed analysis of algorithms for predicting RT intent.

Algorithm	Treatment	Data source	Stage	Intent	N	Sensitivity (%)	PPV (%)
Algorithm #1	RT alone	IPO-Porto	All stages	Curative	47	9.5	100
				Palliative	47	100	11.6
	RT alone	REAL-Oncology	All stages	Curative	681	34.2	98.8
				Palliative	681	99.1	40.7
	RT + SACT	IPO-Porto	All stages	Curative	119	99.1	100
				Palliative	119	100	90.9
	RT + SACT	REAL-Oncology	All stages	Curative	272	85.7	98.3
				Palliative	272	99.1	82.6
	RT + SACT	IPO-Porto	Stage I–II	Curative	30	96.6	100
				Palliative	30	100	50
	RT + SACT	IPO-Porto	Stage IIIA	Curative	58	100	100
				Palliative	58	100	100
	RT + SACT	IPO-Porto	Stage IIIB	Curative	31	100	100
				Palliative	31	100	100
	RT + SACT	REAL-Oncology	Stage I–II	Curative	55	85.7	100
				Palliative	55	100	68.4
	RT + SACT	REAL-Oncology	Stage IIIA	Curative	120	86.5	100
				Palliative	120	100	72.1
	RT + SACT	REAL-Oncology	Stage IIIB	Curative	99	83.3	96.2
				Palliative	99	98.5	92.9
Algorithm #2	RT alone	IPO-Porto	All stages	Curative	47	100	100
				Palliative	47	100	100
	RT + SACT	IPO-Porto	All stages	Curative	119	100	100
				Palliative	119	100	100
Algorithm #3	RT alone	REAL-Oncology	All stages	Curative	714	99.2	99.6
				Palliative	714	99.2	98.3
	RT + SACT	REAL-Oncology	All stages	Curative	277	97.5	100
				Palliative	277	100	98.6

PPV: Positive predictive value; RT: Radiotherapy; SACT: Systemic anticancer therapy.