Introduction
Materials and methods
Patient cases
Patient case: | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Sex | F | F | F | M |
Age | 55 | 61 | 63 | 55 |
Histology: | Breast | Breast | Lung | Renal |
Pain Score VAS | 7 | 5 | 6 | - |
Paraspinal involvement: | Yes | No | Yes | Yes |
Bilsky score: | 1b | 0 | 0 | 2 |
Circumferential epidural disease: | 180° | 90° | 90° | 180° |
Location: | T 12-L1 | C 2 | T 7–8 | L 3 |
Number of involved vertebras: | 2 | 1 | 2 | 1 |
Planning procedure
Step 1: CT-MR image registration
Step 2: delineation of GTV and spinal cord
Step 3: delineation of CTV
Step 4: definition of PTV and PRV
Step 5: treatment planning based on consensus contours
Step 6: treatment planning based on institutional-specific CTV contours
Objectives and constraints for this planning study
Serial tissue | Volume in cm3
| Dose Max in Gy | Endpoint (> Grade 3) |
---|---|---|---|
Spinal cord | <0.035 | 14 | Myelitis |
<0.35 | 10 | ||
<1.2 | 7 | ||
Cauda Equina | <0.035 | 16 | Neuritis |
<5 | 14 | ||
Sacral Plexus | <0.035 | 18 | Neuropathy |
<5 | 14.4 | ||
Esophagusa
| <0.035 | 16 | stenosis/fistula |
<5 | 11.9 | ||
Heart/Pericardium | <0.035 | 22 | Pericarditis |
<15 | 16 | ||
Great vesselsa
| <0.035 | 37 | Aneurysm |
<10 | 31 | ||
Tracheaa and Larynx | <0.035 | 20.2 | stenosis/fistula |
<4 | 10.5 | ||
Skin | <0.035 | 26 | Ulceration |
<10 | 23 | ||
Stomach | <0.035 | 16 | ulceration/fistula |
<10 | 11.2 | ||
Renal hilum/vascular trunk | <2/3 volume | 10.6 | malignant hypertension |
Parallel tissue | Critical volume in cm3
| Dose Max | Endpoint (> Grade 3) |
Lung (Right & Left) | 1000 | 7.4 | Pneumonitis |
Renal cortex (Right & Left) | 200 | 8.4 | Basic renal function |
Calculation of consensus structures
Method for calculation of delineation variability
Method for dosimetric plan comparison
Results
Step 1: CT-MR image registration
case | X in mm | Y in mm | Z in mm | rot X in ° | rot Y in ° | rot Z in ° | |
---|---|---|---|---|---|---|---|
Max range |
1
| 4.7 | 2.2 | 2.7 | 3.1 | 0.8 | 4.4 |
2
| 1.7 | 1.1 | 6.5 | 1.2 | 3.7 | 3.8 | |
3
| 1.8 | 15.9 | 11.8 | 4.1 | 2.9 | 4.5 | |
4
| 2.6 | 2.5 | 3.0 | 12.5 | 2.6 | 3.5 | |
average 1–4
| 2.7 | 5.4 | 6.0 | 5.2 | 2.5 | 4.1 | |
average 1; 2; 4
|
3.0
|
1.9
|
4.1
|
5.6
|
2.4
|
3.9
| |
SD |
1
| 1.7 | 0.9 | 1.0 | 1.1 | 0.4 | 1.6 |
2
| 0.7 | 0.4 | 2.5 | 0.5 | 1.7 | 1.4 | |
3
| 0.7 | 6.9 | 4.8 | 1.7 | 1.2 | 1.8 | |
4
| 1.2 | 1.0 | 1.5 | 4.6 | 1.0 | 1.3 | |
average 1–4
| 1.1 | 2.3 | 2.5 | 2.0 | 1.1 | 1.5 | |
average 1; 2; 4
|
1.2
|
0.8
|
1.7
|
2.1
|
1.0
|
1.4
|
Step 2: delineation of GTV and spinal cord
SD in mm | Range in mm | |||
---|---|---|---|---|
Case | X and Y | Z | X and Y | Z |
1 | 1.3 | 0.6 | 3.1 | 1.5 |
2 | 1.7 | 3.4 | 4.1 | 8.1 |
3 | 1.3 | 0.9 | 2.5 | 2.0 |
4 | 1.8 | 1.5 | 4.0 | 3.6 |
Average | 1.5 | 1.6 | 3.5 | 3.8 |
Step 3: delineation of CTV and organ at risk spinal cord
SD in mm | Range in mm | |||
---|---|---|---|---|
Case | X and Y | Z | X and Y | Z |
1 | 0.6 | 0.3 | 1.6 | 0.8 |
2 | 1.3 | 3.0 | 3.0 | 6.9 |
3 | 0.5 | 0.6 | 1.0 | 1.4 |
4 | 0.9 | 1.0 | 1.9 | 2.3 |
Average | 0.8 | 1.2 | 1.8 | 2.8 |
Step 4 delineation of PTV
Step 5: treatment planning
PTV | ||
---|---|---|
Dmin in Gy | 7.5 | ±1.8 |
D98 in Gy | 12.2 | ±2.0 |
D95 in Gy | 15.2 | ±1.7 |
D90 in Gy | 17.4 | ±1.0 |
Dmean in Gy | 19.4 | ±0.8 |
D05 in Gy | 21.6 | ±1.3 |
D02 in Gy | 21.9 | ±1.4 |
Dmax in Gy | 23.1 | ±1.6 |
Dmax in Gy | D0.1ccm in Gy | V8Gy in ccm | V10Gy in ccm | |||||
---|---|---|---|---|---|---|---|---|
Dose to PRV_SCconsensus (Mean ± SD) | 10.5 | ±1.6 | 9.0 | ±1.5 | 1.5 | ±1.6 | 0.1 | ±0.1 |
Case | CI-Paddick | CI-RTOG | HI-RTOG | Cov-RTOG | ||||
---|---|---|---|---|---|---|---|---|
1 | 0.67 | ±0.08 | 1.11 | ±0.17 | 1.98 | ±0.34 | 0.86 | ±0.06 |
2 | 0.63 | ±0.08 | 1.19 | ±0.24 | 1.64 | ±0.17 | 0.86 | ±0.05 |
3 | 0.70 | ±0.07 | 1.09 | ±0.15 | 1.90 | ±0.31 | 0.87 | ±0.04 |
4 | 0.72 | ±0.05 | 1.10 | ±0.12 | 1.90 | ±0.44 | 0.89 | ±0.05 |
mean | 0.68 | ±0.08 | 1.12 | ±0.18 | 1.86 | ±0.35 | 0.87 | ±0.05 |