Abnormalities by pulmonary regions studied with computer tomography and clinical correlation following local-regional radiotherapy for breast cancer

Abstract

Background: Adjuvant local-regional radiotherapy (RT) is commonly recommended for breast cancer patients. Postoperative adjuvant RT for breast cancer is associated with pulmonary side effects. This study was undertaken to measure the RT-induced pulmonary radiological changes with computer tomography (CT) scan using a CT-adapted modification of the Arriagada classification system, and to correlate these changes to RT techniques, pulmonary complications, and pulmonary function. The aim of the study is to study pulmonary radiological abnormalities with CT following different RT techniques for breast cancer, and their correlation to pulmonary complications and reduction in forced vital capacity (FVC). Materials and Methods: CT scans of the lungs were performed prior to and 4 months following RT in 53 breast cancer patients treated with local-regional RT. The radiological abnormalities were analyzed with a CT-adapted modification of a classification system originally proposed by Arriagada. The patients were monitored for RT-induced pulmonary complications. FVC was measured prior to and 6 months following RT. Statistical analysis used were that increasing CT scores were correlated with pulmonary complications ( P < 0.001). The correlation between density grade (0-3, 4-9) and pulmonary complications (no complication vs slight/severe) was tested using Chi-square exact test for trend (2-sided). In addition, correlation between CT scores and FVC was done. Results: Increasing CT scores were correlated with pulmonary complications ( P < 0.001). The mean reduction of FVC for patients scoring 4-9 (-220 ml) was larger than for patients scoring 0-3 (-15 ml) (Spearson correlation coefficient significant at 0.01 level 2 tailed). But the mean reduction of FVC with greater volume of lung irradiated was not statistically different than lesser volume of lung irradiated ( P > 0.05). Conclusion: Radiological abnormalities detected on CT images and scored with a modification of Arriagada′s classification system can be used as an objective endpoint for pulmonary side effects in postmastectomy RT.

Key words

Breast cancer - computerized tomography - pulmonary complication - pulmonary function - radiotherapy

Publication History

Article published online:
31 December 2020

• References

• 1 Mah K, Poon P, Van Dyk J, Keane T, Majesky I, Rideout D. Assessment of acute radiation-induced pulmonary changes using computer tomography. J Comput Assist Tomogr 1986;10:736-43.
• 2 Pavy JJ, Denekamp J, Letschert J, Littbrand B, Mornex F, Bernier J, et al. Late effects toxicity scoring: The SOMA scale. Int J Radiat Oncol Biol Phys 1995;31:1043-7.
• 3 Arriagada R, Ladron de Guevara JC, Mouriesse H, Hanzen C, Couanet D, Ruffle P, et al. Limited small cell lung cancer treated by combined radiotherapy and chemotherapy: Evaluation of a grading system of lung fibrosis. Radiother Oncol 1989;14:1-8.
• 4 Polansky SM, Ravin CE, Prosnitz LR. Pulmonary changes after primary irradiation for early breast carcinoma. AJR Am J Roentgenol 1980;134:101-5.
• 5 Roswit B, White DC. Severe radiation injuries of the lung. AJR Am J Roentgenol 1977;129:127-36.
• 6 Rothwell RI, Kelly SA, Joslin CA. Radiation pneumonitis in patients treated for breast cancer. Radiother Oncol 1985;4:9-14.
• 7 Marks LB, Halperin EC, Prosnitz LR, Ross M, Vredenburgh JJ, Rosner GL, et al. The Cancer and Leukemia Group B. Post-mastectomy radiotherapy following adjuvant chemotherapy and autologous bone marrow transplantation for breast cancer patients with $ 10 positive axillary lymph nodes. Int J Radiat Oncol Biol Phys 1992;23:1021-6.
• 8 Bentzen SM, Skoczylas JZ, Overgaard M, Overgaard J. Radiotherapy-related lung fibrosis enhanced by tamoxifen. J Natl Cancer Inst 1996;88:918-22.
• 9 Bornstein BA, Cheng CW, Rhodes LM, Rashid H, Stomper PC, Siddon RL, et al. Can simulation measurements be used to predict the irradiated lung volume in the tangential fields in patients treated for breast cancer? Int J Radiat Oncol Biol Phys 1990;18:181-7.
• 10 Mehts CR, Patel NR, Tsiatis AA. Exact significance testing to establish equivalence for ordered categorical data. Biometrics 1984;40:819-25.
• 11 Lingos TI, Recht A, Vicini F, Abner A, Silver B, Harris JR. Radiation pneumonitis in breast cancer patients treated with conservative surgery and radiation therapy. Int J Radiat Oncol Biol Phys 1991;21:355-60.
• 12 Overgaard M, Hansen PS, Overgaard J, Rose C, Andersson M, Bach F, et al. Postoperative radiotherapy in high-risk premenopausal women with breast cancer who receive adjuvant chemotherapy. N Engl J Med 1997;337:949-55.
• 13 Ragaz J, Jackson SM, Le N, Plenderleith IH, Spinelli JJ, Basco VE, et al. Adjuvant radiotherapy and chemotherapy in node-positive premenopausal women with breast cancer. N Engl J Med 1997;337:956-62.