Dosimetric Comparison between Three Dimensional Conformal Radiation Therapy (3DCRT) & Intensity Modulated Radiation Therapy (IMRT) in Mid-Lower Oesophageal Carcinoma

Abstract

Purpose: To investigate if intensity modulated radiation therapy (IMRT) offers a better planning target volume (PTV) coverage and/or lower dose to normal thoracic structures in comparison to three dimensional conformal radiation therapy (3DCRT) in the treatment of mid and lower oesophageal carcinoma patients. Materials and Methods: A prospective study in the period from 2014 till 2015 was held in the radiation therapy department of the National Cancer Institute, Cairo University, in which 20 locally advanced or inoperable mid and lower oesophageal cancer patients were treated by chemo-radiation using 3DCRT technique. IMRT plans were generated for those 20 patients. The 3DCRT and IMRT plans were compared as regards PTV coverage and doses to critical organs at risk. Results: All plans had produced satisfactory PTV coverage with no significant differences noted. The lung V20 for both lungs in 3DCRT was 16.94% ± 4.2% which was increased to 21.42% ± 3.6% in IMRT (p = 0.017). The mean dose to the heart and V30 were higher in IMRT plans while the mean dose to the spinal cord was higher with 3DCRT plans, yet that didn't reach a statistically significant level (p = 0.156). The dose delivered to the liver didn't pose any difference between both techniques. Conclusion: 3DCRT remains to be a feasible cost effective treatment delivery option for mid and lower oesophageal cancer cases with a lower optimization and delivery time than that for IMRT. Moreover, that calls for further dosimetric studies and clinical trials to assess IMRT technique. In our study, IMRT using nine fields didn't prove to be superior to 3DCRT.

Is Escalated Radiation Dose in Definitive Chemoradiotherapy Better for Inoperable Esophageal Carcinoma? A Meta-Analysis and Systematic Review

“…Thus, radiation dose escalation has been proposed as a more effective substitute to improve local-regional and survival rates, especially in Asian population [7] [8] [9]. Additionally, two-dimensional radiotherapy (2D-RT) technology, which has apparent dosage deficiency and cold spots compared with modern radiotherapy techniques [10], thus questions have been raised as to whether dose escalation utilizing computerized tomography (CT)-based radiotherapy approaches could bring about survival benefits with less treatment-related toxicity in the 3D-RT era. In recent years, numerous studies or pooled meta-analyses showed that escalated radiation dose could improve local control (LC) and OS with no increase in serious adverse radiation-related toxicities, raising the possibility that this factor may be advantageous in dCRT [7] [8] [9] [11]- [17].…”