Page 32 - ARNM-3-3

Advances in Radiotherapy
& Nuclear Medicine Brachytherapy versus external beam in local dose escalation

2.7. Effect measures articles were excluded, resulting in 37 full-text studies

Each intervention was assessed by the expert panel being assessed. Ultimately, four studies (one randomized
based on its anticipated benefits, potential risks, and controlled trial and three retrospective analyses) met the
9-12
comparative clinical effectiveness. Interventions were eligibility criteria. These studies included a total of
then categorized into one of the following classifications: 724 patients treated with an IRT boost and 2,837 patients
favorable, uncertain/favorable, uncertain, uncertain/ treated with an EBRT boost (Table 1).
unfavorable, or unfavorable. Furthermore, the strength 3.1.2. Results of individual studies
of each recommendation was graded as strong positive,
conditional positive, conditional negative, or strong The median age across both groups was 57.5 years (range:
negative. 56 – 63 years). IRT was delivered as intraoperative electron
radiotherapy in 113 patients and as an interstitial procedure
9
2.8. Synthesis methods in 611 patients. 10-12 The median dose of IRT was 14.6 Gy
(range: 8.5 – 20 Gy). 9-12 EBRT was delivered with three-
In light of the complexity of the interventions evaluated, 9,10
we aimed to categorize them across multiple dimensions: dimensional photon-based radiotherapy in 285 patients
The median
and as an electron boost in 2,552 patients.
11,12
(i) the type of intervention; (ii) the extent to which
clinical outcomes were influenced by variables such as total EBRT boost dose was 16 Gy delivered in eight
patient age, disease stage, and overall treatment duration; fractions of 2.0 Gy each (range: 16 – 20 Gy).
and (iii) whether the total radiation dose delivered was The median 10-year LC rates were 97.6% (range: 93.7
comparable across treatment modalities. Due to substantial – 99.3%) for the IRT boost group and 97.9% (range: 94.2 –
heterogeneity in therapeutic approaches, clinical contexts, 98.7%) for the EBRT boost group. 9,10,12
study designs, and outcome definitions, a meta-analysis The median 10-year DMFS was 87.4% (range: 84.0 –
was not deemed methodologically appropriate. 87.8%) in the IRT group and 81.6% (range: 79.4 – 90.6%)

2.9. Reporting bias assessment in the EBRT group. 9,10,12 One study reported significantly
improved DMFS in the IRT group compared to EBRT
To evaluate the risk of outcome reporting bias, the reported (5-year DMFS: 95% vs. 77%, p=0.015). 12
outcomes in the published trial articles were compared
with those prespecified in the original trial protocols. In CSS at 10 years was 92.7% in the IRT group and 90.1%
cases where protocols were unavailable, comparisons were in the EBRT group. 10
made between the outcomes outlined in the methods The median 10-year OS rates were 90.4% (range: 89.2 –
sections and those presented in the results sections of the 91.6%) in the IRT group and 86.4% (range: 80.2 – 94.3%)
respective publications. in the EBRT group. 9,12
9,11
2.10. Certainty assessment Late toxicity data were reported in two studies.
Liponecrosis was observed in two patients in the IRT
The certainty of the evidence was independently evaluated group. Grade 2 – 3 telangiectasia and fibrosis occurred in
by two reviewers (VL, MCC) in accordance with the 7.7% and 17.3% of patients in the IRT group, respectively,
GRADE methodology. Key domains assessed included compared to 7.7% and 1.9% in the EBRT group.
consistency of effect, imprecision, indirectness, and
potential publication bias. Based on these criteria, the One study found significantly better cosmetic outcomes
overall confidence in the evidence for each outcome was in the IRT group compared to the EBRT group, with
rated as high, moderate, low, or very low. Summary of consistent differences over time based on both physician
9
11
Findings tables were generated using the GRADEpro GDT and patient evaluations. In contrast, Polgár et al. reported
software. no statistically significant difference in the proportion of
patients achieving excellent or good cosmetic outcomes
3. Results and discussion between the IRT group (88.5%; 46 of 52) and the EBRT
3.1. Breast cancer group (82.7%; 43 of 52; p=0.29).
3.1.1. Study selection 3.2. Prostate cancer
The literature search initially yielded 1,320 records. After 3.2.1. Study selection
removing duplicates and screening for relevance, 521 The literature search identified 1,001 records. After
abstracts were retained for further evaluation. Based removing duplicates and screening for relevance, 513
on the predefined inclusion and exclusion criteria, 484 abstracts were selected for further evaluation. Based on the

Volume 3 Issue 3 (2025) 24 doi: 10.36922/ARNM025160017