Abstract
Purpose or Objective
The effect of (chemo)radiotherapy on head and neck
squamous cell carcinoma can be visualized using MRI.
Adaptation of radiotherapy treatment plans might be
possible based on changes in tumor volume during
treatment, using MRI guided treatment. Furthermore,
different patterns of volume changes might be an
indicator of radiosensitivity and could possibly predict
treatment failure. Therefore the objective of this study is
to follow treatment response with T2 weighted images of
head and neck cancer and to adapt based on this tumor
regression.
Material and Methods
Twenty patients with stage II, III or IV oropharyngeal,
laryngeal or hypopharyngeal squamous cell carcinoma
were included. Two patients had HPV positive tumors.
Treatment consisted of radiotherapy, with or without
concurrent chemotherapy. All patients underwent MRI
prior to and in week 2, 3, 4 and 5 of the radiotherapy
treatment.Imaging was obtained with the patient
positioned in the radiotherapy mask. Tumor delineation
was performed on T2 weighted MR images with fatsuppression
(mDIXON) for the baseline and each
subsequent images. Relative volume changes compared to
the baseline were determined. A follow up of at least 3
months was available for all patients.
Results
During (chemo)radiotherapy tumors generally reduced in
size with each passing week. On average the tumors were
only 50% of their original size at the end of the third week
of treatment. At the end of the fifth week only on average
20% of the original tumor volume was visible on T2
weighted images (fig 1). In one patient, tumor visibly
increased in size from the third week onward. This was the
only patient with a local recurrence within 3 months after
treatment (fig 2). However, in some cases, tumors were
increasingly in time harder to differentiate from
nonmalignant tissues in the treatment area.
Conclusion
During (chemo)radiotherapy, MRI T2 weighted images can
be used to delineate tumor volume. Generally tumors
decrease in size during treatment. It may be possible to
decrease the dose to healthy tissues by adapting
radiotherapy plans based on the changes. It may even be
possible to predict local status after treatment, however
this is subject of ongoing investigation. The availability of
the MR-linac makes treatment adaptation based on daily
T2 weighted MR imaging possible.
The effect of (chemo)radiotherapy on head and neck
squamous cell carcinoma can be visualized using MRI.
Adaptation of radiotherapy treatment plans might be
possible based on changes in tumor volume during
treatment, using MRI guided treatment. Furthermore,
different patterns of volume changes might be an
indicator of radiosensitivity and could possibly predict
treatment failure. Therefore the objective of this study is
to follow treatment response with T2 weighted images of
head and neck cancer and to adapt based on this tumor
regression.
Material and Methods
Twenty patients with stage II, III or IV oropharyngeal,
laryngeal or hypopharyngeal squamous cell carcinoma
were included. Two patients had HPV positive tumors.
Treatment consisted of radiotherapy, with or without
concurrent chemotherapy. All patients underwent MRI
prior to and in week 2, 3, 4 and 5 of the radiotherapy
treatment.Imaging was obtained with the patient
positioned in the radiotherapy mask. Tumor delineation
was performed on T2 weighted MR images with fatsuppression
(mDIXON) for the baseline and each
subsequent images. Relative volume changes compared to
the baseline were determined. A follow up of at least 3
months was available for all patients.
Results
During (chemo)radiotherapy tumors generally reduced in
size with each passing week. On average the tumors were
only 50% of their original size at the end of the third week
of treatment. At the end of the fifth week only on average
20% of the original tumor volume was visible on T2
weighted images (fig 1). In one patient, tumor visibly
increased in size from the third week onward. This was the
only patient with a local recurrence within 3 months after
treatment (fig 2). However, in some cases, tumors were
increasingly in time harder to differentiate from
nonmalignant tissues in the treatment area.
Conclusion
During (chemo)radiotherapy, MRI T2 weighted images can
be used to delineate tumor volume. Generally tumors
decrease in size during treatment. It may be possible to
decrease the dose to healthy tissues by adapting
radiotherapy plans based on the changes. It may even be
possible to predict local status after treatment, however
this is subject of ongoing investigation. The availability of
the MR-linac makes treatment adaptation based on daily
T2 weighted MR imaging possible.
| Original language | English |
|---|---|
| Pages (from-to) | 8-9 |
| Journal | Radiotherapy and Oncology |
| Volume | 132 |
| DOIs | |
| Publication status | Published - Mar 2019 |