Table 2. Summary of conventionally fractionated IMRT or PBT reirradiation studies.

Study	No. patients	Histology	Staging	Median interval to reRT (mo)	Initial RT dose Gy (median)	reRT dose Gy (median)	Local control	Median OS mo (range)	Other therapies	Toxicities
Centingoz et al. [2009]	38	NSCLC	Not described	9	30	25 (10×2.5 Gy)	Not described	3 (NS)	Not described	≥ acute or late grade 3 toxicity (42%), acute toxicity (39%), late toxicity (12%), grade 5 (17.6%)
McAvoy et al. [2013]	33	NSCLC	I: 7/33; II: 5/33; III: 20/33; IV: 1/33	36	63	60	54% locoregional control at 1 year	11.1 [1–32]	45% of patients received chemotherapy prior to reRT; 6% underwent surgery; 6% underwent surgery and chemotherapy; eight patients received concurrent chemotherapy with reRT;	≥ acute grade 3 toxicities, 9% esophageal, 21% pulmonary
Kruser et al. [2014]	37	NSCLC	I: 2/37; II: 5/37; III: 20/37; IV: 10/37	11.2	57	30	Not described	5.1 (0.5–42)	Concurrent chemotherapy given in 33% of patients; palliative RT to non-thoracic sites in 16% of patients; 81% of patients had chemotherapy with first course of RT	Grade 2 pulmonary toxicity of 8.1%, grade 3 pulmonary toxicity of 5.4%; grade 2 esophagitis—10%; late grade 2 pulmonary toxicity of 5.5% and a grade 4 bronchostenosis
McAvoy et al. [2014]	102	NSCLC	I: 29/102; II: 16/102; III: 45/102; IV: 9/102	17	70	60.5	Median local failure free survival of 11.4-month	14.7 (10.3–20.6)	45% of patients received chemotherapy; 5% underwent surgery; 3% underwent surgery and chemotherapy prior to reRT;	≥ acute grade 3 toxicities, 7% esophageal, 10% pulmonary
Chao et al. [2016]	57	NSCLC	I: 12/57; II: 4/57; III: 35/57; IV: 6/57;	19	Not described	66.6	PFS 58% at 1 year	14.9 (NS)	67% of patients received concurrent chemotherapy with reRT	≥ acute grade 3 toxicities in 39% of patients, ≥ late grade 3 toxicities reported in 12% of patients; 6 grade 5 toxicities observed
Ho et al. [2017]	27	NSCLC (81.4%), Other (18.6%)	I: 7/27; II: 4/27; III: 16/27;	29.5	60	66	Median freedom from local failure of 78% at 1 year	18 (NS)	48% of patients received concurrent chemotherapy with reRT	Acute grade 3 pulmonary toxicity in 7% of patients, no ≥ acute grade 3 esophageal toxicity
Badiyan et al. Abstract [2017]	67	NSCLC (90%), SCLC (10%)	Not described	21	59.4 or 50 SBRT (3–5 fractions)	60	Median PFS of 7.9 months and 26% at 1 year	13.2 (NS)	84% of patients received chemotherapy prior to reRT; 30% received concurrent chemotherapy with reRT	Acute grade 3 toxicity in 3% of patients (pneumonia and neck pain), 1% late grade 3 fatigue; no grade 4 toxicities and one death 4.5 months from reRT

NSCLC, non-small cell lung cancer; SCLC, small cell lung cancer; NS, not stated; EBRT, external beam radiation therapy; IMRT, intensity modulated radiation therapy; PBT, proton beam therapy; SBRT, stereotactic body radiation therapy; RT, radiation therapy; reRT, reirradiation therapy; PFS, progression-free survival; LC, local control.