ABSTRACT
Purpose: To evaluate the inadequacy ofplanning target volume [PTV] coverage using a two-dimensional [2D] and two and-one-half-dimensional [2.5D] margin-growing methods compared to a three-dimensional [3D] margingrowing method in the conformal radiotherapy [CRT] planning ofprostate cancer
Methods: PTV 0f 10 patients suffering from organ-confined prostate carcinoma was planned using ARTS 3D treatment planning system. The plan was performed by; 2D, 2.5D, and 3D techniques. The three PTVS were determined by expansion of the gross tumor volume [GTV] by a 1.0-cm margin. The former was obtained by automatically adding the margin in 2.5D and 3D for GTV. In 20 the former was obtained by manual contouring in CT slices. For each patient the three PTVs were compared to assess the deviations of the 20 and 2.5D PTVs from the 3D PTV. For all PTVs conformal plans were designed using the same number offiela'sfor the three PTVs. For each patient dose-volume histograms [DVHS] and isoa'ose distributions were calculated
Results: The 2D and 2.5D margin-growing methods underestimated the PTV by 21.9+/-4.6 % [ ranged from 13.7% to 28.1%] and by 24.6+/-4.8 % [ranged from 15.9% to 30.2%] respectively when compared to the 3D margingrowing method. The mean of underdosage for 3D margin due to planning according to 2D margin is 2.7+/-1.1% [ ranged from 1.01% to 3.33 %], and in planning according to 2.5D margin is 2.2+/-1.8 % [ ranged from 0% to 4.5%] respectively
Conclusion: From the comparison between the DVHs and isodose distributions for different slices. the full 3D GTV-to-PTV expansion is recommended in CRT to avoid underdosage
ABSTRACT
The members of human Melanoma Associated Antigen [MAGE] gene family are highly expressed in human hepatocellular carcinoma [HCC]. The present study aimed to detect tumour cells in the peripheral blood of HCC patients by using mRNA of the MAGE-1 and MAGE-3 genes as specific tumour markers. This study was carried out on 100 subjects included in three groups; group I: HCC patients [n=50], group II: cirrhotic patients [n=25] and group III: apparently healthy subjects as controls [n=25]. Patients of groups I and II were attendants of the Out Patient Clinics of National Liver Institute, Menoufiya University. The mRNA of the MAGE-1 and MAGE-3 genes in peripheral blood mononuclear cells [PBMC] was detected by using nested RT-PCR. Results revealed that of the 50 HCC patients, MAGE-1 and MAGE-3 mRNA were positive in 56% [28/50] and 46% [23/50] of PBMC respectively and 64% [32/50] of HCC samples were detected to express at least one type of MAGE mRNA. The detection of MAGE transcripts in PBMC was correlated with the advanced stages and the tumour size of HCC as 92.9% [26/28] and 100% [23/23] of positive MAGE-1 and MAGE-3 transcripts respectively were detected in HCC cases in stages III and VI. Also, 100% of positive MAGE-1 and MAGE-3 mRNA detected were related to HCC cases having sizes > 4cm. In addition, expression of MAGE-3 was correlated to the evidences of metastasis. On the other hand, detection of MAGE-1 and/or MAGE-3 transcripts was not detected in the PBMC of cirrhotic patients or in the PBMC of healthy controls. No statistical significant correlation was observed between the expression of MAGE genes and the increased levels of alphafoeto protein [AFP], the presence of liver cirrhosis or viral hepatitis. Therefore, these tumour specific antigens can be used as molecular markers for early diagnosis and possible targets for immunotherapy for patients with HCC