Klin Onkol 2008; 21(2): 66-70.
Backgrounds: Positron emission tomography (PET) is used to distinguish between benign and malign tumours, to diagnose relapse or post-therapeutic changes and recentlyto predict treatment response. PET is also a complementary method to determine target volumes in radiotherapy. Using the PET in routine oncology practice can change disease management and improve treatment outcomes of cancer patients. We performed a pilot study to validate the role of PET in staging and in radiotherapy
treatment planning of cervical carcinoma. Patients and Methods: Between March 2005 and May 2007, 51 patients with cervical carcinoma were treated with combination of external beam radiotherapy and HDR brachytherapy, with or without concomitant cisplatin. The lymphatic nodes treatment fi eld size was determined by PET/CT fusion. Treatment results were evaluated by PET 3 and 9 months after completion of radiotherapy. Results: The difference in the results of PET and CT was evaluated in this study. In 32 cases (62.75%) the results of initial PET and CT were identical, in 14 cases (27.45%) the nodal involvement was more extensive according to PET, in 5 cases (9.8%) the nodal involvement was more extensive according to CT. Comparing the results of PET done before and 3 months after the treatment, we found stable disease in 3 cases (5.88%) , , progression of disease in 4 cases (7.84%), partial regression in 3 cases (5.88 %) and in 35 cases (68.63 %) both PET scans were negative. There should not occur any false positive results caused by infl ammatory reaction persisting 3 months after radiotherapy, as was confi rmed by repeating PET 9 months after the treatment. Conclusion: The results of this study confi rmed the important role of PET in diagnosis and treatment of cervical carcinoma and for determination of target volumes in radiotherapy. The predictive value of PET has not yet been validated in our study. PET was integrated into the standard staging of cervical carcinoma in Masaryk Memorial Cancer Institute.
