Ionizing　radiation　is　intensively　used　for　therapeutic　[e.g.,　radiotherapy,　brachytherapy,　and　targeted　radionuclide　therapy　(TRT)],　as　well　as　for　diagnostic　medical　imaging　purposes.　In　these　applications,　the　radiation　dose　given　to　the　patient　should　be　known　and　controlled.　In　conventional　cancer　treatments,　absorbed　dose　calculations　rely　essentially　on　scattering　cross　sections　(CSs)　of　the　primary　high-energy　radiation.　In　more　sophisticated　treatments,　such　as　combined　radio-　and　chemo-therapy,　a　description　of　the　details　of　energy　deposits　at　the　micro-　and　nano-scopic　level　is　preferred　to　relate　dose　to　radiobiological　effectiveness　or　to　evaluate　doses　at　the　biomolecular　level,　when　radiopharmaceuticals　emitting　short-range　radiation　are　delivered　to　critical　molecular　components　of　cancer　cells　(e.g.,　TRT).　These　highly　radiotoxic　compounds　emit　large　densities　of　low-energy　electrons　(LEEs).　More　generally,　LEE　(0-30　eV)　are　emitted　in　large　numbers　by　any　type　of　high-energy　radiation;　i.e.,　about　30　000　per　MeV　of　deposited　primary　energy.　Thus,　to　optimize　the　effectiveness　of　several　types　of　radiation　treatments,　the　energy　deposited　by　LEEs　must　be　known　at　the　level　of　the　cell,　nucleus,　chromosome,　or　DNA.　Such　local　doses　can　be　evaluated　by　Monte　Carlo　(MC)　calculations,　which　account　event-by-event,　for　the　slowing　down　of　all　generations　of　particles.　In　particular,　these　codes　require　as　input　parameters　absolute　LEE　CSs　for　elastic　scattering,　energy　losses,　and　direct　damage　to　vital　cellular　molecules,　particularly　DNA,　the　main　target　of　radiation　therapy.　In　the　last　decade,　such　CSs　have　emerged　in　the　literature.　Furthermore,　a　method　was　developed　to　transform　relative　yields　of　damages　into　absolute　CSs　by　measuring　specific　parameters　in　the　experiments.　In　this　review　article,　we　first　present　a　general　description　of　dose　calculations　in　biological　media　via　MC　simulation　and　give　an　overview　of　the　CSs　available　from　theoretical　calculations　and　gas-phase　experiments.　The　properties　of　LEE　scattering　in　the　gas-phase　are　then　compared　to　those　in　the　condensed　phase.　The　remaining　portion　of　the　article　is　devoted　to　condensed-phase　CSs.　We　provide　absolute　LEE　scattering　CSs　for　electronic,　vibrational,　and　phonon　excitation　of　biomolecules　as　well　as　for　dissociative　electron　attachment,　electron　intra-　and　inter-molecular　stabilization,　and　bond　dissociation,　including　strand　breaks　and　degradation　product　formation.　The　biomolecules　are　O2,　CO2,　H2O,　DNA　bases,　sugar　and　phosphate　unit　analogs,　oligonucleotides,　plasmid　DNA,　and　the　amino　acid　tryptophan.　CSs　for　strand　breaks　in　radiosensitizing　and　chemotherapeutic　molecules　bond　or　not　to　a　short　DNA　strand　are　also　listed.　The　principle　of　each　experimental　technique　and　mathematical　methods　utilized　to　generate　all　condensed-phase　CSs　are　briefly　explained.　The　mechanisms　responsible　for　the　magnitudes　of　the　CSs　are　discussed.　©　2018　Author(s).