Salah satu algoritma perhitungan dosis berkas elektron yang digunakan pada perencanaan radioterapi eksternal adalah algoritma Fermi-Eyges dengan model Hogstrom. Perbandingan antara hasil kalkulasi Fermi-Eyges model Hogstrom dengan hasil pengukuran langsung dilakukan dalam penelitian ini melalui analisa kuantitatif terhadap PDD untuk lima energi (6, 9, 15, 18, dan 21 MeV) dan lima ukuran lapangan (5 cm x 5 cm, 10 cm x 10 cm, 15 cm x 15 cm, 20 cm x 20 cm, dan 25 cm x 25 cm). Kalkulasi dosis dilakukan dengan perangkat lunak Matlab R2009b. PDD hasil perhitungan didapati memiliki diskrepansi rata-rata total 23,19% terhadap PDD hasil pengukuran.Hasil juga menunjukkan bahwa kalkulasi Fermi-Eyges Hogstrom kurang sesuai dengan data pengukuran pada energi tinggi dan lapangan kecil (diskrepansi rata-rata tertinggi ditemukan pada lapangan 5 cm x 5 cm energi 21 MeV senilai 46,33%) dan sesuai pada energi tinggi dan lapangan besar (diskrepansi rata-rata terendah ditemukan pada lapangan 25 cm x 25 cm energi 21 MeV senilai 5,49%).One of the algorithms utilized on electron beam external radiotherapy planning is the Fermi-Eyges (Hogstrom model) formulation. Dose calculation results of Fermi-Eyges (Hogstrom model) formulation for five energy (6, 9, 15, 18, dan 21 MeV) and five field-size (5 cm x 5 cm, 10 cm x 10 cm, 15 cm x 15 cm, 20 cm x 20 cm, dan 25 cm x 25 cm) are compared with those of experimental results for the same parameter. Dose calculation is performed with Matlab R2009b software.

The result showed that calculated PDD disagreed by averaged 23,19% with the experimental result on all energies and field-sizes at all depths. Also shown by the result that Fermi-Eyges Hogstrom calculation disagreed significantly with measurement on high-energy, small field-sized beams (greatest discrepancy was found at 21 MeV, 5 cm x 5 cm beam as great as 46,33% averaged at all depths) while agrees on high-energy, large field-sized beams (least discrepancy was found at 21 MeV, 25 cm x 25 cm beam as much as 5,49% averaged at all depths).