TITLE:
The Use of Intensity Modulated Radiotherapy as a Mean of Reducing Dose to Bone Marrow for Patients with Cancer Cervix Treated at Nci, Cairo, Egypt. Dosimetric Study
AUTHORS:
Mohamed Mahmoud, Mahmoud Shosha, Maha Hassan, Shaimaa Abdelgelil, Sandy Mohamed
KEYWORDS:
IMRT, BMS-IMRT, OAR, PBM
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.8 No.10,
October
31,
2017
ABSTRACT: Purpose: To test the use of Intensity Modulated Radiotherapy (IMRT) to spare the
bone marrow (BM) in patients treated with cancer cervix through using the bone
marrow an organ at risk. Patients and methods: Thirteen patients
with stage (IB2-IIIB) intact cervix cancer were included; C-T simulation was
done with contrast and full bladder with
slice thickness 2.5 mm. Clinical Target Volume (CTV) included the cervix,
uterus, upper half of the vagina, parametrium and regional lymph nodes. The CTV
was expanded by 1 cm to form the Planning Target Volume (PTV). The organ at
risk (OAR) included the bladder and rectum, the external contour of the pelvic
bones to define the Pelvic Bone Marrow (PBM). Four plans were done for every
patient with anteroposterior-posteroanterior (AP/PA), three dimensional
conformal radiotherapy (3DCRT), IMRT, bone marrow-sparing intensity-modulated
pelvic radiotherapy (BMS-IMRT). Results: BMS-IMRT reduced the
V20, V30, V40 and V45 of the BM in comparison to 3DCRT and IMRT plans.
Reduction in V20 with BMS-IMRT plan compared to 3DCRT (p 0.03). The PBM volume
receiving 5, 10 and 20 Gy was
lower AP/PA than BMS-IMRT (p p 0.001 and p 0.04 respectively). The
volumes of the rectum and bladder receiving dose of 40 and 45 Gy were lower in
BMS-IMRT plan compared to AP/PA and 3DCRT plans with p = 0.01 for both of them. PTV
cover was better in the BMS-IMRT and IMRT plans. Conclusion: BMS-IMRT
decreased the irradiated BM volume compared to other techniques. Thus using
BMS-IMRT is recommended to decrease hematological toxicity and avoid treatment
interruption.