Purpose: To determine the changes in pulmonary function tests (PFTs) 0 to 48 months after treatment for breast cancer and lymphoma.
Patients and methods: The alveolar volume (V(A)), vital capacity, forced expiratory volume in 1 second, and corrected transfer factor of carbon monoxide (T(L,COc)) were measured in 69 breast cancer and 41 lymphoma patients before treatment and 3, 18, and 48 months after treatment with radiotherapy alone or radiotherapy in combination with chemotherapy (mechlorethamine, vincristine, procarbazine, prednisone, doxorubicin, bleomycin, vinblastine; cyclophosphamide, epidoxorubicin, fluorouracil; cyclophosphamide, thiotepa, carboplatin; cyclophosphamide, methotrexate, fluorouracil). The three-dimensional dose distribution in the lung of each patient was converted to the mean lung dose. Statistical analysis was used to evaluate the changes in PFT values over time in relation to age, sex, smoking, chemotherapy, and the mean lung dose.
Results: After an initial reduction in PFT values at 3 months, significant recovery was seen at 18 months for all patients. Thereafter, no further improvement could be demonstrated. Reductions in spirometry values and V(A) were related to the mean lung dose only (0.9% per Gy at 3 months and 0.4% per Gy mean dose at 18 months). T(L,COc) decreased 1. 1% per Gy mean dose and additionally decreased 6% when chemotherapy was given after radiotherapy. Chemotherapy administered before radiotherapy reduced baseline T(L,COc) values by 8% to 21%. All patients showed an improvement of 5% at 18 months.
Conclusion: On the basis of the mean lung dose and the chemotherapy regimen, the changes in PFT values can be estimated before treatment within 10% of the values actually observed in 72% to 85% of our patients with healthy lungs.