Impact of irradiation technique and tumor extent in tumor control and survival of patients with unresectable non‐oat cell carcinoma of the lung. Report by the radiation therapy oncology group

• Published in: Cancer 1982-09, Vol.50 (6), p.1091-1099
• Main Authors: Perez, Carlos A., Stanley, Kenneth, Grundy, Graham, Hanson, William, Rubin, Philip, Kramer, Simon, Brady, Luther W., Marks, James E., Perez‐Tamayo, Ruheri, Brown, G. Stephen, Concannon, Joseph P., Rotman, Marvin
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - pathology; Adenocarcinoma - radiotherapy; Carcinoma, Small Cell - pathology; Carcinoma, Small Cell - radiotherapy; Carcinoma, Squamous Cell - pathology; Carcinoma, Squamous Cell - radiotherapy; Follow-Up Studies; Functional Laterality; Humans; Lung Neoplasms - pathology; Lung Neoplasms - radiotherapy; Neoplasm Recurrence, Local; Neoplasm Staging; Radiotherapy - methods; Radiotherapy Dosage
• ISSN: 0008-543X; 1097-0142
• DOI: 10.1002/1097-0142(19820915)50:6<1091::AID-CNCR2820500612>3.0.CO;2-0

An analysis of intrathoracic tumor control was carried out in 378 patients with histologically proven unresectable non‐oat cell carcinoma of the lung treated with definitive radiotherapy, randomized to one of four treatment regimens: 4000 rad split course (2000 rad in five fractions in one week, two weeks rest and additional 2000 rad in five fractions in one week) or 4000, 5000 or 6000 rad continuous courses, five fractions per week. Between 85 and 101 patients are analyzed in each treatment group. The complete plus partial response was 46–51% in the 4000 rad groups in contrast to 61–66% in the 5000 to 6000 rad groups (P = 0.008). The overall two year survival rate was 10–11% for the patients treated with 4000 rad split or continuous course, and 19% in the patients treated with 5000 to 6000 rad. The complete response in patients with tumors 3 cm or less in diameter was 16% when treated with 4000 rad in contrast to 20–31% in those treated with 5000–6000 rad. In the patients with lesions from 4 to 6 cm in diameter, complete and partial tumor regression was 48% in the 4000 rad group, 67% with 5000 rad, and 71% with 6000 rad. These differences are statistically significant (P = 0.033). Intrathoracic recurrences were correlated with the dose of irradiation given: 52% with 4000 rad, 41% with 5000 rad, and 30% with 6000 rad (P = 0.006). An analysis of protocol compliance was carried out in 301 patients with available data, irradiated at the primary site according to protocol instruction (none or minor variation). Median survival for patients treated to the ipsilateral or contralateral hilar lymph nodes according to the protocol varied from 46–50 weeks in contrast to 20–30 weeks for those with major protocol variations in nodal irradiation. Variations in ipsilateral and contralateral nodal irradiation correlated with significant reductions in tumor control (P = 0.02 and P = 0.009, respectively). In addition to patient and tumor characteristics, the technical factors of irradiation are critical parameters that affect tumor control and survival in patients with non‐oat cell bronchogenic carcinoma. Strict quality assurance criteria in radiotherapy are necessary to achieve optimal treatment results and a careful program to evaluate techniques of irradiation and protocol compliance should be maintained in cooperative group studies in order to enhance the validity of clinical trials.