Experimental study on the fractionation schedule for proton irradiation of uveal melanoma

Abstract

Greene melanoma in the anterior chamber of rabbits was irradiated by protons to find the isoeffect curve for proton irradiation fractionated into one, two, three or four doses. The isoeffect curve for tumor tissue remained constant between one- and three-dose fractionations and rose with four-dose fractionation. The isoeffect curve for normal tissue approximately followed the Ellis equation. Therefore, the optimal irradiation schedule should be in the range of three fractions because this best spares normal tissue while delivering a tumoricidal dose to the lesion. The relative reduction of the total dose from four- to one-dose fractions of intraoperative irradiation should be 20%.

Evaluation of eye melanoma treatments in rabbits: A systematic review

“…Of these, 27 articles were included for the qualitative synthesis, with publication dates from 1970 to 2018. Of the selected studies, 19 used PDT as treatment, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] six used radiotherapy [34][35][36][37][38][39] and two used laser. 40,41 No studies with surgical therapy that met the inclusion criteria were obtained.…”

“…Outcome of tumour therapy were evaluated by various methods, including biomicroscopy exams, 17,20,21,24,26,27,30,31,33,40,41 angiographic examination 15–19,21–24,26–28,31,33,40,41 histological examination, 15–23,26–28,30,31,33,34,36,37,40,41 fundoscopy, 18,19,22,23,27,28,32–34,38–41 magnetic spectroscopy, 38 electron microscopy, 24,29,35 ultrasound exam 18,…”

“…36 Since the height of the tumour may influence its complete regression, 34 partial 38,39 to total responses were observed at varying periods of days after treatment, 37 with necrosis areas of variable dimensions. 35 The energy used in laser therapy was related to therapeutic responses. 40,41 Complete regression of tumours was achieved.…”

“…49 Amelanotic Greene hamster melanoma cells were used in almost all revised studies, being used in 16 of the 19 PDT studies 15–18,20,21,24–33 and in five of the six radiotherapy ones. 34,35,37 Mus musculus melanoma cells (B16F10) were used in two PDT studies 19,22 and in two laser studies. 40,41 Human uveal melanoma (92.1MEL cells) were used in a PDT study.…”

“…Several changes were observed, including corneal opacification, iris atrophy, cataract formation, 37 hair loss, epiphora, symblepharon, blepharitis, 35 haemorrhagic choroidal detachments, 38 retinal detachment and vitreous haemorrhage. 34…”