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Advances in Radiotherapy
& Nuclear Medicine Comparison of online ATP versus offline ATS plans

Figure 1. Flowchart of the ATP and ATS workflows
Abbreviations: ATP: Adapt-to-position; ATS: Adapt-to-shape; CT: Computed tomography.

Table 1. Characteristics of the enrolled patients and the radiotherapy group, the CTV, D98, D95, and Dmean of the
treatment modality offline ATS plan were superior compared with those of the

Characteristics N ATP plan (P < 0.05; Table 4). The D95 was 5024.65 ± 23.34
cGy and 4995.50 ± 14.99 cGy in the ATS and ATP plans,
Ages 56.4±12.2 (range, 26 – 78 years) respectively. The Dmax was lower in the ATS plan than in
Body mass index (kg/m ) 23.9±3.5 the ATP plan. A comparison of the PTVs revealed that the
2
FIGO tumor stage (I: II: III: IV) 2:11:10:2 D95 and Dmean were better in the ATS plan than in the ATP
HPV (negative/positive) 21/4 plan (P < 0.05). Furthermore, the Dmax was significantly
Pathological diagnosis lower in the ATS plan than in the ATP plan. No statistically
Squamous cell carcinoma 14 significant difference was observed between the homogeneity
Adenocarcinoma 11 index and conformity index between the two plans. The ATS
plan exhibited a good target coverage (V100% = 96% ± 1%),
Treatment modality
Radical radiotherapy 13 whereas the ATP plan exhibited significant differences in the
corresponding parameters (V100% = 94% ± 1%) (P < 0.05).
Post-operative radiotherapy 12
Abbreviations: HPV: Human papillomavirus; FIGO: International In the post-operative radiotherapy group, the CTV,
federation of gynecology and obstetrics classification. Dmean, D98, and D95 of the offline ATS plan were
better than those of the ATP plan (Table 5). The D95
was 5052.61 ± 67.87 cGy and 5014.41 ± 24.68 cGy in
56.4 ± 12.2 years (range, 26 – 78 years). The majority of the the ATS and ATP plans, respectively. A comparison of
patients (44%) had stage II disease. In total, 13 patients were the PTVs revealed that the Dmean of the offline ATS
included in the radical radiotherapy group and 12 patients plan was better than that of the ATP plan. Furthermore,
in the post-operative radiotherapy group. In total, 78 plans the ATS plan exhibited a good target coverage
were present in the radical radiotherapy patient group (V100% = 0.96% ± 0.01%), and the ATP plan exhibited
(39 using ATS and 39 using ATP). In the post-operative similar coverage (V100% = 0.95% ± 0.009%) (P < 0.05).
radiotherapy patient group, 72 plans were present (36 with
ATS and 36 with ATP). The ATS plan corresponded with 3.2. OAR dosimetric differences
the ATP plan in each patient. Comparison of the OAR in the radical radiotherapy
group revealed that the minimum doses to the bladder
3.1. CTV and PTV dosimetric differences
and rectum were greater in the ATS plan than in the
In the radical radiotherapy group, the Dmax and Dmean ATP plan (P < 0.05; Tables 6 and 7). In the post-operative
of the ATS and ATP plans were better than those of the radiotherapy group, the V20 values of the bladder and
original plan (Table 2). In the post-operative radiotherapy, rectum in the ATS plan were lower than those in the ATP
the Dmean of the ATS and ATP plans was better than that of plan (P < 0.05). The rectum of Dmin in ATS was higher
the reference plan (Table 3). For the target dose, in the radical than that in ATP.

Volume 2 Issue 4 (2024) 4 doi: 10.36922/arnm.4919