Merge pull request e0404#492 from e0404/master_hotfixEffectiveCutoff

Fix issue with effective lateral cutoff for large photon fields

MatRad_Config.m

@@ -152,6 +152,7 @@ function setDefaultProperties(obj)
             obj.propDoseCalc.defaultResolution = struct('x',3,'y',3,'z',3); %[mm]
             obj.propDoseCalc.defaultLateralCutOff = 0.995; %[rel.]
             obj.propDoseCalc.defaultGeometricCutOff = 50; %[mm]
+            obj.propDoseCalc.defaultKernelCutOff = Inf; %[mm]
             obj.propDoseCalc.defaultSsdDensityThreshold = 0.05; %[rel.]
             obj.propDoseCalc.defaultUseGivenEqDensityCube = false; %Use the given density cube ct.cube and omit conversion from cubeHU.
             obj.propDoseCalc.defaultIgnoreOutsideDensities = true; %Ignore densities outside of cst contours
@@ -180,6 +181,7 @@ function setDefaultPropertiesForTesting(obj)
             obj.propDoseCalc.defaultResolution = struct('x',5,'y',6,'z',7); %[mm]
             obj.propDoseCalc.defaultGeometricCutOff = 20;
             obj.propDoseCalc.defaultLateralCutOff = 0.8;
+            obj.propDoseCalc.defaultKernelCutOff = 20; %[mm]
             obj.propDoseCalc.defaultSsdDensityThreshold = 0.05;
             obj.propDoseCalc.defaultUseGivenEqDensityCube = false; %Use the given density cube ct.cube and omit conversion from cubeHU.
             obj.propDoseCalc.defaultIgnoreOutsideDensities = true;

matRad_calcPhotonDose.m

@@ -59,7 +59,24 @@
 set(figureWait,'pointer','watch');
 
 % set lateral cutoff value
-lateralCutoff = matRad_cfg.propDoseCalc.defaultGeometricCutOff; % [mm]
+if ~isfield(pln,'propDoseCalc') || ~isfield(pln.propDoseCalc,'geometricCutOff')
+    pln.propDoseCalc.geometricCutOff =  matRad_cfg.propDoseCalc.defaultGeometricCutOff; % [mm]
+end
+
+lateralCutoff = pln.propDoseCalc.geometricCutOff;
+
+if ~isfield(pln,'propDoseCalc') || ~isfield(pln.propDoseCalc,'kernelCutOff')
+    pln.propDoseCalc.kernelCutOff =  matRad_cfg.propDoseCalc.defaultKernelCutOff; % [mm]
+end
+
+% set kernel cutoff value (determines how much of the kernel is used. This
+% value is separated from lateralCutOff to obtain accurate large open fields)
+kernelCutoff = pln.propDoseCalc.kernelCutOff;
+
+if kernelCutoff < lateralCutoff
+    matRad_cfg.dispWarning('Kernel Cut-Off ''%f mm'' cannot be smaller than geometric lateral cutoff ''%f mm''. Using ''%f mm''!',kernelCutoff,lateralCutoff,lateralCutoff);
+    kernelCutoff = lateralCutoff;
+end
 
 % toggle custom primary fluence on/off. if 0 we assume a homogeneous
 % primary fluence, if 1 we use measured radially symmetric data
@@ -119,12 +136,16 @@
 end
 
 % get kernel size and distances
-kernelLimit = ceil(lateralCutoff/intConvResolution);
+if kernelCutoff > machine.data.kernelPos(end)
+    kernelCutoff = machine.data.kernelPos(end);
+end
+
+kernelLimit = ceil(kernelCutoff/intConvResolution);
 [kernelX, kernelZ] = meshgrid(-kernelLimit*intConvResolution: ...
                             intConvResolution: ...
                             (kernelLimit-1)*intConvResolution);
 
-% precalculate convoluted kernel size and distances
+% precalculate convolved kernel size and distances
 kernelConvLimit = fieldLimit + gaussLimit + kernelLimit;
 [convMx_X, convMx_Z] = meshgrid(-kernelConvLimit*intConvResolution: ...
                                 intConvResolution: ...
@@ -134,7 +155,7 @@
 
 % define an effective lateral cutoff where dose will be calculated. note
 % that storage within the influence matrix may be subject to sampling
-effectiveLateralCutoff = lateralCutoff + fieldWidth/2;
+effectiveLateralCutoff = lateralCutoff + fieldWidth/sqrt(2);
 
 counter = 0;
 matRad_cfg.dispInfo('matRad: Photon dose calculation...\n');
@@ -206,7 +227,7 @@
             % apply the primary fluence to the field
             Fx = F .* Psi;
 
-            % convolute with the gaussian
+            % convolve with the gaussian
             Fx = real( ifft2(fft2(Fx,gaussConvSize,gaussConvSize).* fft2(gaussFilter,gaussConvSize,gaussConvSize)) );
 
             % 2D convolution of Fluence and Kernels in fourier domain