Background
Methods
Target definition and treatment planning
Treatment and image acquisition procedures
Analysis
Results
Patients’ characteristics
Variable | Value | Range |
---|---|---|
Age (y) | 72.2 | (60–78) |
Initial PSA (ng/mL) | 25.9 | (4.0–86.2) |
Gleason score | ||
< 7, n (%) | 0 (0%) | |
= 7, n (%) | 9 (36%) | |
> 7, n (%) | 16 (64%) | |
T-classification | ||
T1c – 2a, n (%) | 7 (28%) | |
T2b, n (%) | 6 (24%) | |
T2c – 3a, n (%) | 12 (48%) | |
Risk classification | ||
Low | 0 (0%) | |
Intermediate | 2 (8%) | |
High | 23 (92%) |
Differences between shifts detected by OBI-FM and CBCT-ST
OBI-FM vs CBCT-ST | AP /mm | SI /mm | LR /mm |
---|---|---|---|
971 pre-treatments (CBCT dependent on kV OBI) | |||
M | −0.10 | −0.06 | −0.16 |
Σ
| 0.35 | 0.33 | 0.22 |
σ
| 0.85 | 0.80 | 0.44 |
206 post-treatments (CBCT independent on kV OBI) | |||
M | −0.49 | − 0.26 | − 0.12 |
Σ
| 0.69 | 0.85 | 0.39 |
σ
| 1.23 | 1.41 | 0.76 |
Differences between intrafractional errors detected by OBI-FM and CBCT-ST
AP /mm | SI /mm | LR /mm | |
---|---|---|---|
OBI-FM for 1177 treatment including 971 and 206 treatments | |||
M | 0.56 | 0.22 | 0.34 |
Σ
| 0.68 | 0.76 | 0.26 |
σ
| 1.66 | 1.62 | 0.75 |
OBI-FM for 206 treatments | |||
M | 0.49 | 0.22 | 0.24 |
Σ
| 0.85 | 1.00 | 0.43 |
σ
| 1.47 | 1.66 | 0.75 |
CBCT-ST for 206 treatments | |||
M | 0.00 | −0.04 | 0.12 |
Σ
| 0.68 | 0.66 | 0.25 |
σ
| 1.08 | 1.21 | 0.50 |
CTV-to-PTV margin definition
Author | Year | Pts | Image data sets | Contouring error (Intra-observer error) | Contouring error (Intra-observer error) | Matching error (Intra-observer error) | Matching error (Intra-observer error) | Intrafractional error | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Observation method |
∑
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σ
| Observation method |
∑
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σ
| Observation method |
∑
|
σ
| Observation method |
∑
|
σ
| Observation method |
∑
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σ
| |||||
Rasch (21) | 1999 | 18 | CT and MRI images | vrt | Intraobserver variability evaluated by 3 ROs CT volumes were larger than the axial MR volumes in 52 of 54 delineations. | ||||||||||||||
lng | – | – | – | – | |||||||||||||||
lat | |||||||||||||||||||
Moseley (13) | 2007 | 15 | 547 MV-and kV-CBCT data sets | vrt | ST in kV CBCT compared with FM in kV CBCT | 1.97 | 2.15 | 5 Observer over 5 Pts. in ST matching with kV CBCT | 1.61 | 2.86 | |||||||||
lng | – | – | 2.07 | 2.29 | 2.21 | 2.85 | – | ||||||||||||
lat | 0.57 | 0.85 | 0.61 | 1.5 | |||||||||||||||
Beltran (39) | 2008 | 40 | images from 1532 fractions | vrt | 2 individuals over 40 frs. of 10pts. in FM matching with kV OBI | 0.3 | 0.4 | 0.90 | 1.80 | ||||||||||
lng | – | – | – | 0.5 | 0.3 | FM in kV OBI | 1.00 | 1.20 | |||||||||||
lat | 0.3 | 0.2 | 0.60 | 1.30 | |||||||||||||||
Bylund (27) | 2008 | 24 | MV CBCT | vrt | 20 MV CBCT images from 10 pts. evaluated by 3 experienced radiation oncologists 2 times per each pts. with 1-month interval variations were 1.6 mm, 1.6 mm, and 1.8 mm in the dimensions of AP, LR, and SI | ||||||||||||||
lng | – | – | – | ||||||||||||||||
lat | |||||||||||||||||||
Graf (10) | 2009 | 23 | images from 184 fractions | vrt | 2.30 | 2.70 | |||||||||||||
lng | – | – | – | – | FM in kV OBI | 1.90 | 2.30 | ||||||||||||
lat | 1.10 | 1.40 | |||||||||||||||||
Lutgendorf (34) | 2011 | 8 | CT, MR, and CBCT | vrt | Evalulated by ROs. For MR and CT images r (xCOM) and r (yCOM) did not exceeded 0.8 mm, whereas r (zCOM) was 0.8 mm and 1.3 mm, respectively | Evaluated by 7 ROs. The RMS of inter-observer standard deviations (r) for all patients was largest on CBCT for all three axes. RMS of the COM displacement on CBCT images was 0.4 mm, 1.1 mm, 1.7 mm in left-right, anterior-posterior and cranio-caudal directions, respectively. | |||||||||||||
lng | – | ||||||||||||||||||
lat | |||||||||||||||||||
Morrow (26) | 2012 | 34 | kV CBCT | vrt | |||||||||||||||
lng | – | – | 20 users | 20 users | – | ||||||||||||||
lat | |||||||||||||||||||
Oehler (35) | 2014 | 20 | 172 and 52 CBCTs before and after RT and 507 kV/kV images | vrt | 3 experienced ROs contoured without MR images | 1.52 | ST in CBCT compared with FM in CBCT (NA due to with endrectal balloon) | 0.77 | 1.09 | FM in CBCT (NA due to with endrectal balloon) | 1.39 | 1.62 | |||||||
lng | – | 2.03 | 0.36 | 0.17 | – | 1.36 | 1.39 | ||||||||||||
lat | 1.68 | 0.49 | 0.93 | 0.92 | 0.97 | ||||||||||||||
Hirose This study | 2018 | 25 | Each 1177 kV OBI and kB CBCT image datasets before RT, and 1177 kV | vrt | 0.85 | 1.47 | |||||||||||||
lng | – | – | – | – | FM in kV OBI | 1.00 | 1.66 | ||||||||||||
lat | 0.43 | 0.75 | |||||||||||||||||
OBI and 206 kV CBCT image datasets after RT | vrt | ST in kV CBCT compared with FM in kV OBI | 0.69 | 1.23 | ST in CBCT (NA due to bias and less reliability) | 0.68 | 1.08 | ||||||||||||
lng | – | – | 0.85 | 1.41 | – | 0.66 | 1.21 | ||||||||||||
lat | 0.39 | 0.76 | 0.25 | 0.50 |
(/ mm) | AP | SI | LR |
---|---|---|---|
Σ
| 0.85 | 1.00 | 0.43 |
σ
| 1.47 | 1.66 | 0.75 |
PTV margin | 3.2 | 3.7 | 1.6 |
(/mm) |
non-compensated
|
compensated
| ||||
---|---|---|---|---|---|---|
AP | SI | LR | AP | SI | LR | |
Σ
| 0.35 | 0.33 | 0.22 | 1.10 | 1.31 | 0.58 |
σ
| 0.85 | 0.80 | 0.44 | 1.91 | 2.18 | 1.07 |
PTV margin | 1.5 | 1.4 | 0.9 | 4.1 | 4.8 | 2.2 |