Quality assurance of internal mammary node irradiation in the DBCG IMN2 study

Lasse Refsgaard; Emma S Buhl; Anders W Mølby Nielsen; Mette S Thomsen; Karen Andersen; Ingelise Jensen; Martin Berg; Ebbe L Lorenzen; Lise B J Thorsen; Jens Overgaard; Stine S Korreman; Birgitte V Offersen

doi:10.1016/j.radonc.2024.110600

Quality assurance of internal mammary node irradiation in the DBCG IMN2 study

Lasse Refsgaard, Emma S Buhl, Anders W Mølby Nielsen^*, Mette S Thomsen, Karen Andersen, Ingelise Jensen, Martin Berg, Ebbe L Lorenzen, Lise B J Thorsen, Jens Overgaard, Stine S Korreman, Birgitte V Offersen

^*Corresponding author for this work

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

1 Citation (Scopus)

Abstract

Purpose/objective: The Danish Breast Cancer Group (DBCG) IMN2 study investigated the gain from internal mammary node irradiation (IMNI) in node-positive breast cancer patients. IMNI was indicated in right-sided patients, but not in left-sided. Target volume delineations were based on bony landmarks in contrast to the contemporary vessel-based ESTRO consensus guideline. Our objective was to compare IMNI doses in right-sided versus left-sided patients. Material/methods: Treatment plans and delineated structures including CTVn_IMN (IMN_old) from 2008 to 2014 were collected from the DBCG RT Nation study. During the study period, IMN_old was only delineated in right-sided patients. Right and left-sided CTVn_IMN structures were auto-segmented following the ESTRO guidelines (IMN_ESTRO). Due to cranial discordance between IMN_old and IMN_ESTRO, the IMN_ESTRO models were separated into IMN_ESTRO_cranial and IMN_ESTRO_intercostal space(IC)1-3, IC1-4, and IC4_only. Results: Treatment plans for 2837 patients were available (62.5 % of patients in the IMN2 study). In right-sided patients, the median IMN_old dose coverage (92.4 %) was higher than IMN_ESTRO (71.7 %), p < 0.001. Dose coverage in IMN_ESTRO_IC1-3 was comparable to IMN_old. Comparing IMN_ESTRO_IC1-3 in all patients by laterality, the median CTVn_V90% was 94.6 % (IQR 64.8–100.0) in right-sided patients and 20.4 % (IQR 0.9–55.8) in left-sided patients, p < 0.001. For right-sided patients, median CTV_V90% was 82.3 % in IMN_ESTRO_IC4_only. Median mean heart doses were lower in right-sided patients (1.2 Gy) than in left-sided (2.3 Gy), p < 0.001. Median mean lung doses were higher in right-sided patients (16.0 Gy) than in left-sided (12.7 Gy), p < 0.001. Conclusion: For IMN_ESTRO_IC1-3, we found a significantly higher IMN dose coverage in right-sided than in left-sided patients supporting treatment according to study guidelines in the DBCG IMN2 study.

Original language	English
Article number	110600
Journal	Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
Volume	202
Pages (from-to)	110600
ISSN	0167-8140
DOIs	https://doi.org/10.1016/j.radonc.2024.110600
Publication status	Published - Jan 2025

Keywords

Auto-segmentation
Internal mammary node irradiation
Quality assurance
The DBCG IMN2 study

Access to Document

10.1016/j.radonc.2024.110600

Cite this

Refsgaard, L., Buhl, E. S., Nielsen, A. W. M., Thomsen, M. S., Andersen, K., Jensen, I., Berg, M., Lorenzen, E. L., Thorsen, L. B. J., Overgaard, J., Korreman, S. S., & Offersen, B. V. (2025). Quality assurance of internal mammary node irradiation in the DBCG IMN2 study. Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, 202, 110600. Article 110600. https://doi.org/10.1016/j.radonc.2024.110600

@article{a53fa317bbc44eca836081ae4551b91b,

title = "Quality assurance of internal mammary node irradiation in the DBCG IMN2 study",

abstract = "Purpose/objective: The Danish Breast Cancer Group (DBCG) IMN2 study investigated the gain from internal mammary node irradiation (IMNI) in node-positive breast cancer patients. IMNI was indicated in right-sided patients, but not in left-sided. Target volume delineations were based on bony landmarks in contrast to the contemporary vessel-based ESTRO consensus guideline. Our objective was to compare IMNI doses in right-sided versus left-sided patients. Material/methods: Treatment plans and delineated structures including CTVn_IMN (IMN_old) from 2008 to 2014 were collected from the DBCG RT Nation study. During the study period, IMN_old was only delineated in right-sided patients. Right and left-sided CTVn_IMN structures were auto-segmented following the ESTRO guidelines (IMN_ESTRO). Due to cranial discordance between IMN_old and IMN_ESTRO, the IMN_ESTRO models were separated into IMN_ESTRO_cranial and IMN_ESTRO_intercostal space(IC)1-3, IC1-4, and IC4_only. Results: Treatment plans for 2837 patients were available (62.5 % of patients in the IMN2 study). In right-sided patients, the median IMN_old dose coverage (92.4 %) was higher than IMN_ESTRO (71.7 %), p < 0.001. Dose coverage in IMN_ESTRO_IC1-3 was comparable to IMN_old. Comparing IMN_ESTRO_IC1-3 in all patients by laterality, the median CTVn_V90% was 94.6 % (IQR 64.8–100.0) in right-sided patients and 20.4 % (IQR 0.9–55.8) in left-sided patients, p < 0.001. For right-sided patients, median CTV_V90% was 82.3 % in IMN_ESTRO_IC4_only. Median mean heart doses were lower in right-sided patients (1.2 Gy) than in left-sided (2.3 Gy), p < 0.001. Median mean lung doses were higher in right-sided patients (16.0 Gy) than in left-sided (12.7 Gy), p < 0.001. Conclusion: For IMN_ESTRO_IC1-3, we found a significantly higher IMN dose coverage in right-sided than in left-sided patients supporting treatment according to study guidelines in the DBCG IMN2 study.",

keywords = "Auto-segmentation, Internal mammary node irradiation, Quality assurance, The DBCG IMN2 study",

author = "Lasse Refsgaard and Buhl, {Emma S} and Nielsen, {Anders W M{\o}lby} and Thomsen, {Mette S} and Karen Andersen and Ingelise Jensen and Martin Berg and Lorenzen, {Ebbe L} and Thorsen, {Lise B J} and Jens Overgaard and Korreman, {Stine S} and Offersen, {Birgitte V}",

year = "2025",

month = jan,

doi = "10.1016/j.radonc.2024.110600",

language = "English",

volume = "202",

pages = "110600",

journal = "Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology",

issn = "0167-8140",

publisher = "Elsevier Ireland Ltd",

}

Refsgaard, L , Buhl, ES , Nielsen, AWM, Thomsen, MS, Andersen, K, Jensen, I, Berg, M, Lorenzen, EL, Thorsen, LBJ , Overgaard, J , Korreman, SS & Offersen, BV 2025, 'Quality assurance of internal mammary node irradiation in the DBCG IMN2 study', Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, vol. 202, 110600, pp. 110600. https://doi.org/10.1016/j.radonc.2024.110600

Quality assurance of internal mammary node irradiation in the DBCG IMN2 study. / Refsgaard, Lasse ; Buhl, Emma S ; Nielsen, Anders W Mølby et al.
In: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, Vol. 202, 110600, 01.2025, p. 110600.

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

TY - JOUR

T1 - Quality assurance of internal mammary node irradiation in the DBCG IMN2 study

AU - Refsgaard, Lasse

AU - Buhl, Emma S

AU - Nielsen, Anders W Mølby

AU - Thomsen, Mette S

AU - Andersen, Karen

AU - Jensen, Ingelise

AU - Berg, Martin

AU - Lorenzen, Ebbe L

AU - Thorsen, Lise B J

AU - Overgaard, Jens

AU - Korreman, Stine S

AU - Offersen, Birgitte V

PY - 2025/1

Y1 - 2025/1

N2 - Purpose/objective: The Danish Breast Cancer Group (DBCG) IMN2 study investigated the gain from internal mammary node irradiation (IMNI) in node-positive breast cancer patients. IMNI was indicated in right-sided patients, but not in left-sided. Target volume delineations were based on bony landmarks in contrast to the contemporary vessel-based ESTRO consensus guideline. Our objective was to compare IMNI doses in right-sided versus left-sided patients. Material/methods: Treatment plans and delineated structures including CTVn_IMN (IMN_old) from 2008 to 2014 were collected from the DBCG RT Nation study. During the study period, IMN_old was only delineated in right-sided patients. Right and left-sided CTVn_IMN structures were auto-segmented following the ESTRO guidelines (IMN_ESTRO). Due to cranial discordance between IMN_old and IMN_ESTRO, the IMN_ESTRO models were separated into IMN_ESTRO_cranial and IMN_ESTRO_intercostal space(IC)1-3, IC1-4, and IC4_only. Results: Treatment plans for 2837 patients were available (62.5 % of patients in the IMN2 study). In right-sided patients, the median IMN_old dose coverage (92.4 %) was higher than IMN_ESTRO (71.7 %), p < 0.001. Dose coverage in IMN_ESTRO_IC1-3 was comparable to IMN_old. Comparing IMN_ESTRO_IC1-3 in all patients by laterality, the median CTVn_V90% was 94.6 % (IQR 64.8–100.0) in right-sided patients and 20.4 % (IQR 0.9–55.8) in left-sided patients, p < 0.001. For right-sided patients, median CTV_V90% was 82.3 % in IMN_ESTRO_IC4_only. Median mean heart doses were lower in right-sided patients (1.2 Gy) than in left-sided (2.3 Gy), p < 0.001. Median mean lung doses were higher in right-sided patients (16.0 Gy) than in left-sided (12.7 Gy), p < 0.001. Conclusion: For IMN_ESTRO_IC1-3, we found a significantly higher IMN dose coverage in right-sided than in left-sided patients supporting treatment according to study guidelines in the DBCG IMN2 study.

AB - Purpose/objective: The Danish Breast Cancer Group (DBCG) IMN2 study investigated the gain from internal mammary node irradiation (IMNI) in node-positive breast cancer patients. IMNI was indicated in right-sided patients, but not in left-sided. Target volume delineations were based on bony landmarks in contrast to the contemporary vessel-based ESTRO consensus guideline. Our objective was to compare IMNI doses in right-sided versus left-sided patients. Material/methods: Treatment plans and delineated structures including CTVn_IMN (IMN_old) from 2008 to 2014 were collected from the DBCG RT Nation study. During the study period, IMN_old was only delineated in right-sided patients. Right and left-sided CTVn_IMN structures were auto-segmented following the ESTRO guidelines (IMN_ESTRO). Due to cranial discordance between IMN_old and IMN_ESTRO, the IMN_ESTRO models were separated into IMN_ESTRO_cranial and IMN_ESTRO_intercostal space(IC)1-3, IC1-4, and IC4_only. Results: Treatment plans for 2837 patients were available (62.5 % of patients in the IMN2 study). In right-sided patients, the median IMN_old dose coverage (92.4 %) was higher than IMN_ESTRO (71.7 %), p < 0.001. Dose coverage in IMN_ESTRO_IC1-3 was comparable to IMN_old. Comparing IMN_ESTRO_IC1-3 in all patients by laterality, the median CTVn_V90% was 94.6 % (IQR 64.8–100.0) in right-sided patients and 20.4 % (IQR 0.9–55.8) in left-sided patients, p < 0.001. For right-sided patients, median CTV_V90% was 82.3 % in IMN_ESTRO_IC4_only. Median mean heart doses were lower in right-sided patients (1.2 Gy) than in left-sided (2.3 Gy), p < 0.001. Median mean lung doses were higher in right-sided patients (16.0 Gy) than in left-sided (12.7 Gy), p < 0.001. Conclusion: For IMN_ESTRO_IC1-3, we found a significantly higher IMN dose coverage in right-sided than in left-sided patients supporting treatment according to study guidelines in the DBCG IMN2 study.

KW - Auto-segmentation

KW - Internal mammary node irradiation

KW - Quality assurance

KW - The DBCG IMN2 study

UR - http://www.scopus.com/inward/record.url?scp=85209086493&partnerID=8YFLogxK

U2 - 10.1016/j.radonc.2024.110600

DO - 10.1016/j.radonc.2024.110600

M3 - Journal article

C2 - 39521277

SN - 0167-8140

VL - 202

SP - 110600

JO - Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology

JF - Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology

M1 - 110600

ER -

Quality assurance of internal mammary node irradiation in the DBCG IMN2 study

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this