Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT06222190 |
| Other study ID # |
UME-ID-11766 |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
August 2, 2023 |
| Est. completion date |
February 2025 |
Study information
| Verified date |
January 2024 |
| Source |
University Hospital, Essen |
| Contact |
Christoph Pöttgen, MD |
| Phone |
+49 201 723 |
| Email |
christoph.poettgen[@]uk-essen.de |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational [Patient Registry]
|
Clinical Trial Summary
In patients with lung carcinoma who receive radiotherapy preoperatively or alternatively
curative, high-dose radiotherapy instead of surgery, there are also deformations of the
thorax from fraction to fraction.
Currently, ART for lung carcinomas is carried out as part of patient care in the radiotherapy
clinic. Patients are irradiated during repeated breath-holding manoeuvres in deep
inspiration. The breath-holding manoeuvre is practised several times before the daily
irradiation. An optical surface detection device is available for this purpose, which is used
to compare the body surface in the patient's thorax area on the treatment table with the
target surface to be achieved during radiotherapy planning, which took place days before the
current fraction. If the target surface is reproducibly achieved, a conebeam CT is taken to
determine the current tumour extent and the deformations occurring in comparison to the dose
distribution to be applied. For this purpose, the normal tissues heart, lung and tracheal
tree are automatically contoured by the Ethos therapy system in the cone-beam CT. A
specialist physician and a physicist are present at the Ethos device during this process.
These organ contours are used to determine the extent of the current target volume and the
adaptive radiotherapy plan is adjusted to the new target volume. If the current tumour extent
is not sufficiently covered by the initial radiotherapy plan planned for the series with its
planned tolerances, or if the surrounding normal tissue is exposed to too much radiation,
then the online adaptive radiotherapy plan for the current treatment is selected by the
specialist. Otherwise, the initial radiotherapy plan is used by the planning CT as for IGRT.
The aim of this study is to treat patients in ART readiness on the Ethos therapy device over
10 radiotherapy fractions. The dose distribution is always compared with the adaptive and the
initial series plan on the anatomy of the day by the specialist and medical physics expert.
The ART plan is applied when dosimetric advantages are present. The aim of this study is to
prospectively analyse in how many patients safety margins around the clinical target volume
can be reduced with ART compared to IGRT. The percentage of patients who benefit from ART
will be determined prospectively. The criterion for a relevant benefit from ART is the
effective uniform dose (EUD) in the target volume with the accumulated dose distribution
across the first 7 fractions. If the EUD is below 95% of the target dose with IGRT and above
95% of the target dose with ART, then an advantage is determined with ART. Patients with a
benefit from ART receive ART for the further fractions of the series, while the others
continue to be treated with IGRT.
Description:
With online-adaptive radiotherapy (ART), the radiotherapy plan can be adapted to the
anatomical changes before each radiotherapy fraction. The basis for adaptation is a cone-beam
CT with the patient on the treatment table at the start of each radiotherapy fraction.
Adaptive radiotherapy is a further development of image-guided radiotherapy (IGRT), which is
now the basic standard in radiotherapy. Here, a cone beam CT is also performed at the start
of each fraction, but this is only used to position the patient in relation to the radiation
field arrangement of the initial radiation plan approved for the series, so that predefined
landmarks match the target position in the planning CT as closely as possible. However, the
radiotherapy plan itself cannot be adapted to deformations in the body during IGRT, e.g. due
to different bowel and bladder fillings. IGRT is currently carried out on all linear
accelerators at the radiotherapy clinic. For online adaptive radiotherapy (ART), which allows
the radiotherapy plan to be adapted to the anatomical deformities of the day online on the
treatment table, the ETHOS® radiotherapy system from Varian-Siemens has been available at the
radiotherapy clinic for a year as a medical device with handling authorisation from the
district government. This therapy device enables on-line adaptive plan adjustment within
10-20 minutes.
In patients with lung carcinoma who receive radiotherapy preoperatively to reduce the size of
the tumour before surgery or alternatively curative, high-dose radiotherapy instead of
surgery, there are also deformations of the thorax from fraction to fraction. For example,
the depth of breathing during deep inspiration radiotherapy can change depending on the shape
of the day. Ventilation disturbances caused by the tumour may increase or decrease, pleural
effusions may occur or tumour shrinkage may occur. Furthermore, the strength of the various
respiratory muscles can vary from day to day, as can the intra-abdominal pressure.
Currently, ART for lung carcinomas is carried out as part of patient care in the radiotherapy
clinic at the University Hospital Essen. Patients are irradiated during repeated
breath-holding manoeuvres in deep inspiration. The pure irradiation time takes about 1.5
minutes. The breath-holding manoeuvre is practised several times before the daily
irradiation. An optical surface detection device is available for this purpose, which is used
to compare the body surface in the patient's thorax area on the treatment table with the
target surface to be achieved during radiotherapy planning, which took place days before the
current fraction. If the target surface is reproducibly achieved, a conebeam CT is taken to
determine the current tumour extent and the deformations occurring in comparison to the dose
distribution to be applied. For this purpose, the normal tissues heart, lung and tracheal
tree are automatically contoured by the Ethos therapy system in the cone-beam CT. A
specialist physician and a physicist are present at the Ethos device during this process.
These organ contours are used to determine the extent of the current target volume and the
adaptive radiotherapy plan is adjusted to the new target volume. If the current tumour extent
is not sufficiently covered by the initial radiotherapy plan planned for the series with its
planned tolerances, or if the surrounding normal tissue is exposed to too much radiation,
then the online adaptive radiotherapy plan for the current treatment is selected by the
specialist. Otherwise, the initial radiotherapy plan is used by the planning CT as for IGRT.
The aim of this study is to treat 30 patients in ART readiness on the Ethos therapy device
over 10 radiotherapy fractions. The dose distribution is always compared with the adaptive
and the initial series plan on the anatomy of the day by the specialist and medical physics
expert. The ART plan is then applied with dosimetric advantages. The aim of this study is to
prospectively analyse in how many patients safety margins around the clinical target volume
can be reduced with ART compared to IGRT. After the first 7 of the 10 fractions to be
administered in ART readiness, the dose is accumulated over these fractions. The percentage
of patients who benefit from ART will be determined prospectively. The criterion for a
relevant benefit from ART is the effective uniform dose (EUD) in the target volume with the
accumulated dose distribution across the 7 fractions. If the EUD is below 95% of the target
dose with IGRT and above 95% of the target dose with ART, then an advantage is determined
with ART. Such dose accumulations accompanying a radiotherapy series were not possible in the
past. Patients with a benefit from ART receive ART for the further fractions of the series,
while the others continue to be treated with IGRT.
