This is of particular relevance in the case of charged particles radiotherapy, where energy losses and scattering effects are not negligible. Thermoluminescent [6] or Radiochromic detectors [7] (off-line approach), silicon diodes [8, 9, 10], diamond detectors [11, 12, 13], and MOSFETs (Metal-oxide-semiconductor field-effect transistors) [14, 15] (online approach) are conventionally used for in vivo dosimetry [16]. Thermoluminescent dosimeters [6] may be small in size and tissue equivalent but they require a long series of pre- and postirradiation processes and a calibration procedure to be used in the clinical practice. They are not off-line detectors nor usable for real-time dosimetry. Radiochromic films show an excellent spatial resolution; they are tissue equivalent, providing 2D dosimetric information. On the other hand, they are passive detectors, not allowing for real-time measurements. Moreover, their response may be affected by improper handling and scanner performances. Silicon diodes are standard reference dosimeters for a variety of applications in radiotherapy including quality assurance in stereotactic modalities and in vivo dosimetry. Their major drawback lies in their relatively low radiation resistance, especially when used in charged particle beams. Diamonds detectors present high sensitivity and spatial resolution comparable to that of silicon diode detectors, low leakage current, and high radiation hardness. On the other hand, some drawbacks limit their use such as high costs and, for the natural diamonds case, long delivery time due to suitable stone selection. Moreover, synthetic diamond detectors present some disadvantages (such as the control of type and amount of incorporated impurities) that seriously limit the production of detector-grade crystals and strongly affect the response stability. The MOSFETs are able to achieve excellent spatial resolution because of their high sensitivity and small sensitive volume. In particular, the MOSkin, a patented dosimetry based on MOSFET technology and recently introduced by CMRP (Centre for Medical Radiation Physics, University of Wollongong, Australia), is also able to produce a real-time readout and provide a reproducible water equivalent depth of dose measurement of 0.07 mm (suitable for measurements of dose delivered on the patient's skin) [17]. MOSFETs' main disadvantages are finite lifetime (they can collect about 100 Gy as maximum), angular and energy dependence, and sensitivity change with accumulated dose. Moreover, MOSFETs do not provide real-time beam current monitoring. Their information on the dose is accessible only at the end of patient irradiation [18]. All the abovementioned devices can be positioned directly on the patient's skin in order to provide information on the dose deposited but they all intercept and perturb the beam. Moreover, only diodes and diamond detectors are able to follow the beam current trend during the treatment in a real-time modality. In this work, we will discuss the characteristics of an innovative detection approach for relative dose monitoring, based on the use of a simple and commercial electrode as that used in an electrocardiogram. We will call the name of this detector \"Electrode\". A patient undergoing a charged particle radiation treatment absorbs a well-defined quantity of charge and, therefore, is subjected to a net local charge imbalance. The charge disequilibrium generates a potential difference that will produce a current flow through an external, ground-based, floating electrode positioned on the patient's skin, outside the radiation field. The current generated during the potential discharge is directed to a transimpedance, low-pass, and low-noise amplifier, acting as an high-precision picoamperemeter. The current is hence integrated. The measured charge corresponds to the net-deposited charge in the patient that can finally be connected to the absorbed dose.