الفهرس 
EpidemiologyOnly 14 pages are availabe for public view
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Abstract
Lung cancer is the leading cause of cancer death in the United States. Approximately a third of patients with newly diagnosed non-small cell lung cancer (NSCLC) have locally or regionally advanced disease not amenable for surgical resection. In Egypt, lung cancer in general, and NSCLC especially in the locally advanced stage is quite a common disease although the exact incidence of which is unknown as there is no national cancer registry.
In the past radiation therapy was considered the standard therapy for patients with inoperable stage IIIA or IIIB non-small cell lung cancer (NSCLC), with poor local control and early development of distant metastases. Adding chemotherapy to radiation treatment was the logic next step in order to improve treatment outcome. Sequential chemo-radiation (chemo-RT) was found to have a better median survival, when compared to different radiotherapy only regimens. Several randomized trials comparing sequential to concurrent chemo-RT demonstrated the superiority of the concurrent approach. In order to improve the outcome obtained with concurrent chemo-RT, clinical research is focusing on additional combination chemotherapy administered in the induction or consolidation setting in addition to the standard concurrent chemo-RT. Poor median survival gain was obtained by adding induction chemotherapy to the concurrent regimen as compared to concurrent only regimen, on the other hand, more trials showed a median survival benefit by adding consolidation chemotherapy to concurrent chemo-RT.
It was demonstrated that there is a relation between radiation dose and response. 3D-conformal radiation therapy (3D-CRT) allows for radiation dose escalation by increasing confidence in treatment planning through more accurate definition of tumor volumes and normal tissues as well as improving tools for visualizing dose distributions surrounding these structures. Omission of elective nodal irradiation (ENI) was associated with a very low incidence of isolated nodal failure (INF), and allowed for more radiation dose escalation with acceptable therapeutic ratio. The integration of functional imaging with FDG-PET for radiotherapy treatment planning is an important advance that will further mitigate the potential impact of ENI in locally advanced NSCLC. PET imaging may also refine radiotherapy target volumes by displaying the extent of “active” disease, including differentiating tumor from postobstructive atelectasis.
The aim of the present study was to compare the conventional 2D radiotherapy with elective nodal irradiation (ENI) to the more recent 3D conformal radiation treatment without ENI, as regards to different outcome parameters. The radiation treatment in the 2D and 3D groups was delivered concurrently with weekly paclitaxel/carboplatin, and followed by 2 full systemic cycles of the same chemotherapeutic agents as consolidation. The study primary endpoints were overall survival (OS) and progression free survival (PFS). Secondary endpoints included were toxicity, objective response (OR), locoregional control (LRC), pattern of failure, and isolated nodal failure (INF).
In the present study, we concluded that the use of 3D-confromal radiation therapy (3D-CRT) without elective nodal irradiation (ENI), was safer and more tolerable than the conventional radiation treatment, and allowed for the delivery of more radiation dose to the tumor while not exceeding the tolerance doses of surrounding healthy organs. Additionally, more patients in the 3D group were able to receive more consolidation chemotherapy. For all what is previously mentioned, patients in the 3D group had better objective response (OR), locoregional control (LRC), progression free survival (PFS), and overall survival (OS). What’s more, the omission of ENI was associated with minimal isolated nodal failures (INF). Additionally, this study proved that adding consolidation chemotherapy to the concurrent treatment plays a key role in improving both PFS and OS. Nowadays in the United States, the 2D planning has almost completely abandoned. IMRT is gaining popularity with caution, IGRT is starting to flourish