Limits...
Compensability index for compensation radiotherapy after treatment interruptions.

Putora PM, Schmuecking M, Aebersold D, Plasswilm L - Radiat Oncol (2012)

Bottom Line: We developed a software tool in java programming language based on existing recommendations to compensate for treatment interruptions.The compensability index represents an evaluation of the suitability of compensatory radiotherapy in a single number based on the number of days used for compensation and the preference of preserving the originally planned tumour effect or not exceeding the originally planned normal tissue effect.The compensability index calculation may serve as a decision support system based on existing and established recommendations.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Radiation Oncology, Kantonsspital St. Gallen, Rorschacherstrasse 95, St. Gallen 9000, Switzerland. Paul.Putora@kssg.ch

ABSTRACT

Background: The goal of our work was to develop a simple method to evaluate a compensation treatment after unplanned treatment interruptions with respect to their tumour- and normal tissue effect.

Methods: We developed a software tool in java programming language based on existing recommendations to compensate for treatment interruptions. In order to express and visualize the deviations from the originally planned tumour and normal tissue effects we defined the compensability index.

Results: The compensability index represents an evaluation of the suitability of compensatory radiotherapy in a single number based on the number of days used for compensation and the preference of preserving the originally planned tumour effect or not exceeding the originally planned normal tissue effect. An automated tool provides a method for quick evaluation of compensation treatments.

Conclusions: The compensability index calculation may serve as a decision support system based on existing and established recommendations.

Show MeSH

Related in: MedlinePlus

Calculating the late effect dose in percent from the compensation treatment for maximum compensation of tumour effect (offensive extreme), the tumor BED is 100% resulting in an increase of the normal tissue BED by 6.7%.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3539912&req=5

Figure 4: Calculating the late effect dose in percent from the compensation treatment for maximum compensation of tumour effect (offensive extreme), the tumor BED is 100% resulting in an increase of the normal tissue BED by 6.7%.

Mentions: A sample calculation is shown in Figure4. A head&neck cancer patient received only 30 of 35 planned fractions of 2Gy in the originally planned time period (46days). In this example five days are available to compensate the treatment interruption. For each day beyond the 4th week of treatment, the effective tumour dose is reduced by 0.9 Gy per day. The BED10planned represents the biologically equivalent dose (BED) that was intended to be delivered to the tumour. The BED3planned represents the effect on normal tissue. The applied dose is represented by BED10applied and BED3applied respectively. To achieve the same tumour effect a total tumour BED of 67.8Gy is required (the same value as the BED10planned). A loss of 0.9Gy per day after the 4th week is subtracted (including the 5 days of treatment prolongation due to compensatory treatment). When the formula is solved a dose per fraction of 2.62Gy is obtained. The BED3new is calculated using this dose per fraction and a new BED value for normal tissue is determined. The BED3ratio represents the ratio between BED3new and BED3original, in this case 106.7%. In this example the compensation treatment was calculated to maintain the originally planned tumour dose leading to a BED10ratio of 100%.


Compensability index for compensation radiotherapy after treatment interruptions.

Putora PM, Schmuecking M, Aebersold D, Plasswilm L - Radiat Oncol (2012)

Calculating the late effect dose in percent from the compensation treatment for maximum compensation of tumour effect (offensive extreme), the tumor BED is 100% resulting in an increase of the normal tissue BED by 6.7%.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3539912&req=5

Figure 4: Calculating the late effect dose in percent from the compensation treatment for maximum compensation of tumour effect (offensive extreme), the tumor BED is 100% resulting in an increase of the normal tissue BED by 6.7%.
Mentions: A sample calculation is shown in Figure4. A head&neck cancer patient received only 30 of 35 planned fractions of 2Gy in the originally planned time period (46days). In this example five days are available to compensate the treatment interruption. For each day beyond the 4th week of treatment, the effective tumour dose is reduced by 0.9 Gy per day. The BED10planned represents the biologically equivalent dose (BED) that was intended to be delivered to the tumour. The BED3planned represents the effect on normal tissue. The applied dose is represented by BED10applied and BED3applied respectively. To achieve the same tumour effect a total tumour BED of 67.8Gy is required (the same value as the BED10planned). A loss of 0.9Gy per day after the 4th week is subtracted (including the 5 days of treatment prolongation due to compensatory treatment). When the formula is solved a dose per fraction of 2.62Gy is obtained. The BED3new is calculated using this dose per fraction and a new BED value for normal tissue is determined. The BED3ratio represents the ratio between BED3new and BED3original, in this case 106.7%. In this example the compensation treatment was calculated to maintain the originally planned tumour dose leading to a BED10ratio of 100%.

Bottom Line: We developed a software tool in java programming language based on existing recommendations to compensate for treatment interruptions.The compensability index represents an evaluation of the suitability of compensatory radiotherapy in a single number based on the number of days used for compensation and the preference of preserving the originally planned tumour effect or not exceeding the originally planned normal tissue effect.The compensability index calculation may serve as a decision support system based on existing and established recommendations.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Radiation Oncology, Kantonsspital St. Gallen, Rorschacherstrasse 95, St. Gallen 9000, Switzerland. Paul.Putora@kssg.ch

ABSTRACT

Background: The goal of our work was to develop a simple method to evaluate a compensation treatment after unplanned treatment interruptions with respect to their tumour- and normal tissue effect.

Methods: We developed a software tool in java programming language based on existing recommendations to compensate for treatment interruptions. In order to express and visualize the deviations from the originally planned tumour and normal tissue effects we defined the compensability index.

Results: The compensability index represents an evaluation of the suitability of compensatory radiotherapy in a single number based on the number of days used for compensation and the preference of preserving the originally planned tumour effect or not exceeding the originally planned normal tissue effect. An automated tool provides a method for quick evaluation of compensation treatments.

Conclusions: The compensability index calculation may serve as a decision support system based on existing and established recommendations.

Show MeSH
Related in: MedlinePlus