<abstract xmlns="http://www.w3.org/1999/xhtml"><sec id="j_raon-2018-0007_s_005_w2aab3b7c14b1b6b1aab1c18b1Aa"><h3>Background</h3><p>The aim of the study was to investigate the feasibility and safety of experimental fractionation using intensity modulated radiation therapy with a simultaneous integrated boost (IMRT-SIB) to shorten the overall treatment time without dose escalation in preoperative radiochemotherapy of locally advanced rectal cancer.</p></sec><sec id="j_raon-2018-0007_s_006_w2aab3b7c14b1b6b1aab1c18b2Aa"><h3>Patients and methods</h3><p>Between January 2014 and November 2015, a total of 51 patients with operable stage II-III rectal adenocarcinoma were treated. The preoperative treatment with intensity modulated radiation therapy (IMRT) and a pelvic dose of 41.8 Gy and simultaneously delivered 46.2 Gy to T2/3 and 48.4 Gy to T4 tumour in 22 fractions, with standard concomitant capecitabine, was completed in 50 patients out of whom 47 were operated. The median follow-up was 35 months.</p></sec><sec id="j_raon-2018-0007_s_007_w2aab3b7c14b1b6b1aab1c18b3Aa"><h3>Results</h3><p>The rate of acute toxicity G ≥ 3 was 2.4%. The total downstaging rate was 89% and radical resection was achieved in 98% of patients. Pathologic complete response (pCR) was observed in 25.5% of patients, with 2-year local control (LC), disease free survival (DFS), and overall survival (OS) of 100% for this patient group. An intention-to-treat analysis revealed pN to be a significant prognostic factor for DFS and OS (P = 0.005 and 0.030, respectively). LC for the entire group was 100%, and 2-year DFS and OS were 90% (95 % CI 98.4–81.6) and 92.2% (95% CI 99.6–84.7), respectively.</p></sec><sec id="j_raon-2018-0007_s_008_w2aab3b7c14b1b6b1aab1c18b4Aa"><h3>Conclusions</h3><p>The experimental regime in this study resulted in a high rate of pCR with a low acute toxicity profile. Excellent early results translated into encouraging 2-year LC, DFS, and OS.</p></sec></abstract>

BackgroundThe aim of the study was to investigate the feasibility and safety of experimental fractionation using intensity modulated radiation therapy with a simultaneous integrated boost (IMRT-SIB) to shorten the overall treatment time without dose escalation in preoperative radiochemotherapy of locally advanced rectal cancer.Patients and methodsBetween January 2014 and November 2015, a total of 51 patients with operable stage II-III rectal adenocarcinoma were treated. The preoperative treatment with intensity modulated radiation therapy (IMRT) and a pelvic dose of 41.8 Gy and simultaneously delivered 46.2 Gy to T2/3 and 48.4 Gy to T4 tumour in 22 fractions, with standard concomitant capecitabine, was completed in 50 patients out of whom 47 were operated. The median follow-up was 35 months.ResultsThe rate of acute toxicity G ≥ 3 was 2.4%. The total downstaging rate was 89% and radical resection was achieved in 98% of patients. Pathologic complete response (pCR) was observed in 25.5% of patients, with 2-year local control (LC), disease free survival (DFS), and overall survival (OS) of 100% for this patient group. An intention-to-treat analysis revealed pN to be a significant prognostic factor for DFS and OS (P = 0.005 and 0.030, respectively). LC for the entire group was 100%, and 2-year DFS and OS were 90% (95 % CI 98.4–81.6) and 92.2% (95% CI 99.6–84.7), respectively.ConclusionsThe experimental regime in this study resulted in a high rate of pCR with a low acute toxicity profile. Excellent early results translated into encouraging 2-year LC, DFS, and OS.

Preoperative intensity-modulated chemoradiation therapy with simultaneous integrated boost in rectal cancer: 2-year follow-up results of phase II study

Radiology and Oncology

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

BackgroundThe aim of the study was to investigate the feasibility and safety of experimental fractionation using intensity modulated radiation therapy with a...

	IMRT-SIB But-Hadzic et al.16 N = 46	3D CRT Focas et al.32 N = 385		IMRT-SIB But-Hadzic et al.16 N = 46	IMRT-SIB Li et al.10 N = 58
			p			p
TRG 4	12 (26%)	40 (10%)	0.004	12 (26 %)	19 (33 %)	0.302
TRG 2–3	29 (63%)	254 (66%)	0.404	29 (63 %)	20 (35 %)	0.003
TRG 0–1	5 (11%)	91 (24%)	0.031	5 (11 %)	19 (32 %)	0.007

Treatment	Pelvis TD/d/BED (Gy)	Tumour T≤3 TD/d/BED (Gy)	Tumour T4 TD/d/BED (Gy)
3D CRT	45 / 1.8 / 37.5	50.4 / 1.8 / 40.9	54 / 1.8 / 43.9
IMRT-SIB	41.8 / 1.9 / 35.9	46.2 / 2.1 / 42.1	48.4 / 2.2 / 45.2

Preoperative intensity-modulated chemoradiation therapy with simultaneous integrated boost in rectal cancer: 2-year follow-up results of phase II study

Article Category: Research Article

Published Online: Feb 08, 2018

Page range: 23 - 29

Received: Sep 08, 2017

Accepted: Sep 17, 2017

DOI: https://doi.org/10.1515/raon-2018-0007

© 2018 Jasna But-Hadzic, Vaneja Velenik

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Figure 1

Figure 2

Figure 3

Comparison of tumour regression grade in patients with R0 resection

Biologic effective dose (BED) comparison for standard 3-dimensional conformal radiotherapy (3D CRT) and intensity modulated radioation therapy with simultaneous boost (IMRT-SIB) as experimental fractionation

Influence of potential prognostic factors on overall survival (OS) and disease free survival (DFS)

Prognostic factor	OS	DFS
Age	ns	ns
Gender	ns	ns
WHO PS	ns	ns
Tumour grade	ns	ns
cTumour stage according the AJCC, 7th edition22	ns	ns
cNodal stage according the AJCC, 7th edition22	ns	ns
TRG	ns	ns
TRG prognostic group	ns	ns
pTumour stage^d	ns	ns
pNodal stage^d	p = 0.005	p = 0.039
pCR pathologic complete response
Adjuvant chemotherapy chemotherapy	ns	ns
5-6 vs. ≤4 cycles calculated for 36 patients with indication for adjuvant chemotherapy; ns = not specific (p > 0.05).	p = 0.009	p = 0.012