Treatment of advanced salivary gland tumours with neutron radiotherapy

Thesis (MSc)--Stellenbosch University, 2016.ENGLISH SUMMARY : Background: Success rates in the treatment of salivary gland malignancies are associated with completeness of surgical resection with or without postoperative radiotherapy. For patients with unresectable tumours, radiotherapy is an option to attempt to gain local control and improve survival. Different modalities of radiotherapy are available and fast neutrons represent a form of radiotherapy effective in controlling locally advanced salivary gland malignancies. We report on 22 patients treated for locally advanced parotid gland malignancies at iThemba Laboratory for Accelerator Based Sciences via a tertiary institution in Cape Town, South Africa. Methods: Records of patients with unresectable parotid gland malignancies treated with neutron radiotherapy at a tertiary institution between January 1991 and December 2012 were reviewed retrospectively. Twenty-two patients were eligible for statistical analysis. Results: Complete, partial and no response rates were 64%, 14% and 22%, respectively. Of the 14 patients with a complete response, 3 recurred with the earliest recurrence being at 18 months. Locoregional control was 80% and 69% at 2 and 5 years respectively. Twelve out of the 22 patients died post treatment. Overall survival at 2 years was 40% and at 5 years 35%. Seven cases of CTCAE grade 3 and above late toxicities were observed. These included bone necrosis, eardrum perforation and skin ulceration. Conclusions: Treatment modality of this group of patients depends on availability. Response rates of parotid gland malignancy to neutron radiotherapy in this small cohort are comparable to historical controls.AFRIKAANSE OPSOMMING : Agtergrond: Die suksesvolle behandeling van speekselklier maligniteite word deur die volledigheid van chirurgiese reseksie bepaal. Sukses is onafhanklik van adjuvante radioterapie. In gevalle waar ‘n tumor nie-resekteerbaar is nie, is radioterapie ‘n opsie om plaaslike beheer en verbeterde oorlewing te verkry. Verskeie radioterapie modaliteite is beskikbaar vir bestraling van hierdie maligniteite. Vinnige neutrone is ‘n effektiewe opsie in die behandeling van plaaslik gevorderde speekselklier maligniteite. Hierdie verslag vervat die inligting van 22 pasiente wat vir lokaal gevorderde parotisklier malignitieite te iThemba Laboratorium, Kaapstad behandel is. Metode: Pasient rekords is retrospektief nagegaan. Gevalle het gestrek vanaf Januarie 1991 tot-en-met Desember 2012. Slegs gevalle van nie-resekteerbare parotis maligniteit is ingesluit. Twee-en-twintig pasiente het aan die kriteria van die studie voldoen en het deel van die statistiese analise uitgemaak. Resultate: Volledige-, gedeeltelike- en geen respons koerse was 64%, 14% en 22% onderskeidelik. Drie van die veertien pasiente wat aanvanklik volledig gerespondeer het, het herhaling van siekte ontwikkel. Die vroegste van hierdie herhalings was op 18maande. Plaaslike beheer was 80% en 69% teen twee- en vyf jaar onderskeidelik. Twaalf van die 22 pasiente in die studie het na afloop van behandeling afgesterf. Algehele oorlewing teen 2 jaar en 5 jaar was 40% en 35% onderskeidelik. Graad 3 en hoer CTCAE chroniese newe-effekte is in sewe gevalle waargeneem. HIerdie newe-effekte het been nekrose, timpaniesemembraan perforasie en vel ulserasie ingesluit. Gevolgtrekking: Gebruik van die behandelingsmodaliteit beskryf in hierdie studie, word bepaal deur die beskikbaarheid daarvan. In die betrokke kohort is die respons koers van parotis maligniteite tot neutron terapie vergelykbaar met die van historiese kontrole groepe