Correlation between toxicity and dosimetric parameters for adjuvant intensity modulated radiation therapy of breast cancer: a prospective study.
Sci Rep
; 11(1): 3626, 2021 02 11.
Article
in En
| MEDLINE
| ID: mdl-33574446
ABSTRACT
ORCID 0000-0001-6019-7309. In the treatment of breast cancer, intensity-modulated radiation therapy (IMRT) reportedly reduces the high-dose irradiation of at-risk organs and decreases the frequency of adverse events (AEs). Comparisons with conventional radiotherapy have shown that IMRT is associated with lower frequencies of acute and late-onset AEs. Here, we extended a prospective, observational, single-center study of the safety of IMRT to a second investigating center. Patients scheduled for adjuvant IMRT after partial or total mastectomy were given a dose of 50 Gy (25 fractions of 2 Gy over 5 weeks), with a simultaneous integrated boost in patients having undergone conservative surgery. 300 patients were included in the study, and 288 were analyzed. The median follow-up period was 2.1 years. The 2-year disease-free survival rate [95% CI] was 93.4% [89.2-96.0%]. Most AEs were mild. The most common AEs were skin-related-mainly radiodermatitis [in 266 patients (92.4%)] and hyperpigmentation (in 178 (61.8%)). 35% and 6% of the patients presented with grade 2 acute skin and esophageal toxicity, respectively. Only 4 patients presented with a grade 3 event (radiodermatitis). Smoking (odds ratio) [95% CI] = 2.10 [1.14-3.87]; p = 0.017), no prior chemotherapy (0.52 [0.27-0.98]; p = 0.044), and D98% for subclavicular skin (1.030 [1.001-1.061]; p = 0.045) were associated with grade ≥ 2 acute AEs. In a univariate analysis, the mean dose, (p < 0.0001), D2% (p < 0.0001), D50% (p = 0.037), D95% (p = 0.0005), D98% (p = 0.0007), V30Gy (p < 0.0001), and V45Gy (p = 0.0001) were significantly associated with grade ≥ 1 acute esophageal AEs. In a multivariate analysis, D95% for the skin (p < 0.001), D98% for the subclavicular skin and low D95% for the internal mammary lymph nodes were associated with grade ≥ 1 medium-term AEs. The safety profile of adjuvant IMRT after partial or total mastectomy is influenced by dosimetric parameters. TRIAL REGISTRATION ClinicalTrials.gov NCT02281149.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Radiotherapy Dosage
/
Breast Neoplasms
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Radiotherapy, Adjuvant
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Radiotherapy, Intensity-Modulated
Type of study:
Etiology_studies
/
Incidence_studies
/
Observational_studies
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Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Aged
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Female
/
Humans
/
Middle aged
Language:
En
Journal:
Sci Rep
Year:
2021
Document type:
Article
Affiliation country:
France
Publication country:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
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UK
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UNITED KINGDOM