Individualised Radiation Dose Determination on Basis of Normal Tissue Dose Constraints in Patients With Non-Small-Cell Lung Cancer: A Phase I Study
Radiotherapy is treatment of choice for inoperable lung cancer. Research has shown that the
survival rate as well as the local control rate is low. If chemotherapy treatment is added
it leads to a slightly better outcome. The radiotherapy treatment often causes pneumonitis
and/or esophagitis. So damage to the normal tissue restricts the radiation dose that can be
However, several studies have shown that higher doses lead to better local control.
Furthermore it is evident that the radiotherapy treatment should be given in a short time,
preferably the treatment time should not exceed 32 days.
To avoid a higher toxicity the normal tissue has to be spared, but to increase the local
control rate the tumor dose must be as high as possible. This dilemma can only be solved by
using very sophisticated treatment planning techniques in combination with a biologically
superior treatment schedule. This schedule consists of delivering radiation dose twice a day
instead of once, thus keeping the overall treatment time as low as possible.
For the whole patient population, the mean lung dose can to a great extend predict the
probability for developing radiation pneumonitis and the post-radiotherapy lung function. A
logical next step is to determine the dose of radiotherapy on an individualised calculation
of the maximum tolerated dose, being defined as the mean lung dose and the spinal cord dose.
The objective of this trial is to investigate whether individualised radiation dose
calculation based on a mean lung dose and the constraints of the spinal cord, in combination
with an overall treatment time of less than 32 days, and only irradiating the primary tumor
and the PET scan positive mediastinal areas is safe.
Allocation: Non-Randomized, Endpoint Classification: Safety Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
incidence of steroid dependent (grade 2 or more) radiation pneumonitis 6 months after the last radiotherapy dose.
Dirk De Ruysscher, PHD
Maastricht Radiation Oncology (MAASTRO clinic)
Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)