Study designs of evaluations included in the review
Randomised and quasi-randomised controlled trials were eligible for inclusion.
Specific interventions included in the review
Studies comparing radiotherapy versus chemoradiotherapy were eligible for inclusion. Concurrent chemoradiotherapy was defined as cytotoxic therapy during a course of radical radiotherapy. Radical radiotherapy was defined as delivering, by conventional fractionation or altered fractionation, at least 4000 cGy to the gross tumour volume by conventional fractionation or altered fractionation. Studies assessing the effect of hypoxic sensitisers were excluded.
The studies were divided into daily chemoradiotherapy and weekly chemoradiotherapy regimens. In daily regimens, chemotherapy was delivered on sequential days during radiotherapy. In weekly regimens, chemotherapy was generally delivered over sequential weeks during radiotherapy, although there were some variations in individual studies.
The included studies varied in the type, dose, and frequency of drug therapy. However, in most cases, daily regimens involved the delivery of lower doses of chemotherapy and weekly protocols involved relatively higher doses of chemotherapy delivered less frequently. In some studies chemotherapy was not delivered throughout the duration of radiotherapy.
The authors reported the drugs, timing of chemotherapy, and radiotherapy regimen for each included study. In 9 of the 10 studies a cisplatin or carboplatin-containing chemotherapy regimen was used. The total dose of radiotherapy ranged from 45 to 69.6 Gy. Five studies used conventional fractionation and 5 studies used altered fractionation schemes.
Participants included in the review
Studies of people with inoperable NSCLC were eligible. NSCLC was defined as inoperable when there were medical contraindications to surgery or unresectable disease. People with stage I, II or III histologically confirmed disease and no clinical or radiological evidence of distant metastases were included. The authors reported the disease stage of participants in the individual studies. They did not report demographic or other clinical characteristics.
Outcomes assessed in the review
The authors did not explicitly state any outcomes that the studies had to include in order to be eligible for the review. The main outcome measure of the review was mortality from any cause (relative risk of death) at 1, 2 and 3 years after diagnosis. The secondary outcomes included: significant toxicity, defined as incidence of grade 3 or 4 (using the World Health Organization classification); acute oesophagitis and/or oesophageal fibrosis or fistulas; acute pneumonitis and/or pulmonary fibrosis; and acute neutropenia.
How were decisions on the relevance of primary studies made?
The authors reported that each study identified for inclusion was reviewed, but they did not state how the papers were selected for the review, or how many reviewers performed the selection.