Marciana Nona Duma

An easy way to determine bone mineral density and predict pelvic insufficiency fractures in patients treated with radiotherapy for cervical cancer

Abstract Purpose The aim of this study was to investigate whether bone mineral density (BMD) as measured in planning computed tomographies (CTs) by a new method is a risk factor for pelvic insufficiency fractures (PIF) after radio(chemo)therapy (R(C)T) for cervical cancer. Methods 62 patients with cervical cancer who received definitive or adjuvant radio(chemo)therapy between 2013 and 2017 were reviewed. The PIF were detected on follow-up magntic resonance imaging (MRI). The MRI of the PIF patients was registered to the planning CT and the PIF contoured. On the contralateral side of the fracture, a mirrored structure of the fracture was generated (mPIF). For the whole sacral bone, three lumbar vertebrae, the first and second sacral vertebrae, and the PIF, we analyzed the BMD (mg/cm3), V50Gy, Dmean, and Dmax. Results Out of 62 patients, 6 (9.7%) had a fracture. Two out of the 6 patients had a bilateral fracture with only one of them being symptomatic. PIF patients showed a significantly lower BMD in the sacral and the lumbar vertebrae (p < 0.05). The BMD of the contoured PIF, however, when comparing to the mPIF, did not reach significance (p < 0.49). The difference of the V50Gy of the sacrum in the PIF group compared to the other (OTH) patients, i.e. those without PIF, did not reach significance. Conclusion The dose does not seem to have a relevant impact on the incidence of PIF in our patients. One of the predisposing factors for developing PIF after radiotherapy seems to be the low BMD. We presented an easy method to assess the BMD in planning CTs.

Correlations of UICC tumor stage and tumor regression on T2-weighted MRI sequences during definitive radiotherapy of cervical cancer

Background: The purpose of this study is to detect a correlation between the preradiation tumor staging and the relative volumetric regression of the primary tumor through external beam radiation therapy (EBRT). Methods: Clinical data of 32 patients with a mean age of 60±12 years treated with primary radiation therapy (RT) of cervical carcinoma were analyzed. Union Internationale Contre le Cancer (UICC) stages were T1 = 4 patients, T2 = 15 patients, T3 = 8 patients, T4 = 5 patients; N1 = 26 patients, N0 = 6 patients; and M0 = 25 patients, M1 = 7 patients. All patients received pelvic magnetic resonance imaging (MRI) before RT as well as during RT. The cervical primary tumor was delineated as gross tumor volume (ptGTV) in T2-weighted MRI sequences. We compared ptGTV reduction by stage, lymph node status, metastatic status, and grading. Results: Mean ptGTV reduction during RT was 61.4±28.9%. T1 tumors shrank by 88.2±13.4%, T2 by 67.6±28.7%, T3 by 50.8±23.6%, and T4 by 38.7±27.2%. The difference in tumor shrinkage was statistically significant between the lower T stages and the higher T stages ( p < 0.05). There was no statistical difference in the mean ptGTV before treatment in the group with lymph node metastases (LNM) (54.1±47.7 cm3) as compared to the group without LNM (76.6±52.2 cm3). Nonetheless, ptGTV shrank significantly differently: by 68.9±25.7% (N1 patients) and by 29.0±17.7% (N0 patients). No significant differences in ptGTV shrinkage were observed in M0 versus M1 and G2 versus G3 tumors. Conclusion: There is a correlation between mean ptGTV reduction during EBRT and tumor stages. Tumors with higher T stages shrank less under radiation treatment, and the ptGTV of N1 patients responded better than that of N0 patients.