Intensity diffraction tomography (I-DT) is an imaging method that reconstructs the complex-valued refractive index distribution of a weakly scattering object without explicit knowledge of the wavefield phase. In this work, a novel scanning protocol for I-DT is proposed that involves the use of plane-wave and spheriail wave probing wavefields. A useful feature of the scanning protocol is that two in-line intensity measurements are acquired on a detector-plane whose distance from the object remains fixed. Accordingly, the translation of the detector that is required in classic in-line measurement geometries is avoided. A reconstruction algorithm that exploits tomographic symmetries is developed and demonstrated by use of computer-simulation studies.