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

resulting in 74 studies being assessed in full. Ultimately, 3.6. Anal cancer
nine retrospective studies were included in the final 3.6.1. Study selection
analysis 3,4,19-25 (Table 4). These studies focused exclusively
on dosimetric comparisons; none reported clinical The literature search identified 350 records. After removing
outcome data. duplicates and excluding irrelevant publications, 125
abstracts were selected for screening. Based on the inclusion
3.4.2. Results of individual studies criteria, 111 articles were excluded, leaving 14 studies for
IRT was delivered as image-guided IRT, with a median full-text analysis. Ultimately, five retrospective studies met
total dose of 28 Gy (range: 20 – 30 Gy). 3,4,19-25 EBRT was the eligibility criteria, 30-34 including 489 patients treated
delivered as IMRT, CyberKnife, stereotactic radiotherapy, with exclusive concomitant radio-chemotherapy followed
helical tomotherapy, and intensity-modulated proton by either an IRT or EBRT boost.
beam therapy in four, 4,19,22,25 two, two, 20,21 one, and one 3.6.2. Results of individual studies
3,24
26
22
studies, respectively. The median prescribed total EBRT
dose was 28 Gy. The median 5-year LC rates were 87.8% (range: 79 – 97.2%)
in the IRT boost group and 72.8% (range: 62 – 87.5%) in
Five studies showed that IRT was significantly associated the EBRT boost group. Two studies reported significantly
with better target coverage. 4,20,22,24,25 and six studies reported higher LC rates in the IRT boost group compared to the
lower doses to OARs compared with EBRT. 3,4,19,20,25,26 EBRT group. 34,35
3.5. Head-and-neck cancer The median 5-year CSS was 91% in the IRT boost group
33
3.5.1. Study selection and 78% in the EBRT boost group (p=0.272). One study
reported a 5-year CSS of 100% in patients treated with an
The literature search yielded 1,980 records. After early-stage IRT boost. 31
removing duplicates and screening for relevance, 145
The median 5-year OS rates were 74.6% (range: 66 –
abstracts were selected for further evaluation. Based 78.7%) in the IRT boost group and 67.7% (range: 51.6 –
on the inclusion criteria, 120 articles were excluded, 80%) in the EBRT boost group. 31-34
leaving 25 studies to be assessed in full. Ultimately,
four retrospective studies and one prospective study The median 5-year DMFS was 92.9% (range: 85 – 97%)
met the eligibility criteria. 27-31 These studies included a for the IRT boost and 85.6% (range: 77 – 94%) for the
total of 617 patients treated with exclusive radiotherapy EBRT boost. 32,34
or chemoradiotherapy followed by an IRT boost, and The median 5-year colostomy-free survival rates were
387 patients treated with the same initial approach 76.8% (range: 65.4 – 97%) in the IRT group and 63.1%
followed by an EBRT boost. (range: 47.6 – 80%) in the EBRT boost group. 32,34
3.5.2. Results of individual studies Two studies reported data on toxicity. 31,34 Acute skin
toxicity greater than grade 2 was observed in 8% of patients
The median 5-year LC rates were 85% (range: 77.8 – 94%)
in the IRT boost group and 73.7% (range: 55 – 97%) in the in the IRT boost group and 23% in the EBRT boost group
29
EBRT boost group. One study reported significantly higher (p=0.14). Diarrhea greater than grade 2 occurred in
29
LC in the IRT group compared to the EBRT group. 27 6% of patients in both groups. Hematological toxicity
was significantly lower in the IRT group compared to the
CSS at 5 years was 88.9% in the IRT boost group and EBRT group (0% vs. 13%, p=0.04). No study reported
31
77% in the EBRT boost group. 28 statistically significant differences in severe toxicity
The mean 3-year OS rates were 74% and 74.5% for the between the two groups. Chronic proctitis was reported in
IRT and EBRT boost groups, respectively. 27,32 3.8 – 32% of patients. 31,34
The median 5-year disease-free survival was 77% 4. Conclusion
(range: 61 – 92.4%) in the IRT boost group and 71.6% IRT is indicated both as a standalone modality and in
(range: 43 – 92%) in the EBRT boost group. 28-30
combination with other treatment approaches, including
Three studies reported data on toxicity. 27,28,31 One study modern EBRT and surgery, depending on the clinical
reported a higher rate of grade >3 late dysphagia in the context. A substantial body of evidence supports its integral
IRT group compared to the VMAT group (39 [18.1%] vs. role in the global oncologic treatment paradigm. The IRT
21 [9.8%], p=0.01). Budrukkar et al. showed that IRT process typically involves a multidisciplinary team of
29
29
resulted in a significant reduction in xerostomia. specialists engaged at various stages, from patient referral
Volume 3 Issue 3 (2025) 26 doi: 10.36922/ARNM025160017