JSON settings for ROE (models)

The functional forms of several dosimetric models are distributed with CERR. Associated model parameters are specified through JSON format files. This includes parameters required for bio-normalization of planned doses, i.e., the fraction number or fraction size used in developing the model.

JSON fields

General

• Name : Name of the model
• Type : May be "TCP", "BED" , or "NTCP".

For fractionation correction

• fractionCorrect: "Yes" or "No"
• correctionType: "fsize" or "nfrx"
• fractionSize: Fraction size of modelled dataset (required for correctionType: fsize)
• stdNumFractions: No. fractions of modelled dataset (required for correctionType: nfrx)
• abRatio: Radiosensitivity (α/β) in Gy

Functional form

• function: Function name defining model form.
  Model forms distributed with CERR are detailed here. Custom implementations should follow the established function signature:

   outcome = functionName(paramS, doseBinsV, volBinsV)

Model parameters

Each parameter is specified through 4 fields

• val: Parameter value or function name to evaluate. Set t 1 for constant parameters.

• weight : Coefficient. Set to fixed value for constant parameters.

• type : An array of values specifying data types of value & weight inputs, respectively.
  May be "string", "bin"(for binary) or "cont" (for numeric inputs).

• cteg: Specify supported values (e.g.: cteg =[0,1]) for binary type variables.

• desc: Map labels to descriptions (e.g.: desc =["No","Yes"]) for binary type variables only.

• Syntax for structure-specific parameters

   "structure":{
                  "structName1": {
                                   "param1":{
                                              "val": val
                                              "weight": weight
                                              "type": [val_type, weight_type]
                                              "cteg": [cteg1, cteg2]
                                            }
              }

Example

JSON settings for models distributed with ROE are available here.

E.g. Esophagitis model [1]
{
	"name": "Esophagitis (Huang)",
	"type": "NTCP",
	"stdNumFractions": 35,
	"fractionCorrect": "Yes",
	"correctionType": "nfrx",
	"abRatio": 10,
	"parameters": {
		
		"concurrentChemo": {    
				"val": 1,
				"weight": 1.5,
				"type": ["bin", "cont"],
				"cteg": [0,1],
				"desc": ["No", "Yes"]
                          },


		
 		"structures": {
			       "Esophagus":{
                			  "meanDose": {
							"val": "calc_meanDose",
 							"weight": 0.0688,
							"type": ["string", "cont"],
							"cteg": ["calc_meanDose","calc_meanDose"]
                                    	               }
				          }
			},

                "constant": { 
				"val": 1,
				"weight": -3.13,
				"type": ["cont", "cont"],
				"cteg": [0, 1]
		            }
	               },
	"function": "logitFn"
}

References

1. Huang, E. X., Hope, A. J., Lindsay, P. E., Trovo, M., El Naqa, I., Deasy, J. O., & Bradley, J. D. (2011). Heart irradiation as a risk factor for radiation pneumonitis. Acta Oncologica, 50(1), 51-60.