ABSTRACT
AIM: Stereotactic ablative radiotherapy (SABR) involves the delivery of high doses of precisely targeted radiation in a shorter time period than conventional radiotherapy. The aim of this study was to compare the outcomes of lung-based SABR in a New Zealand cohort to the global literature. METHODS: A single-institution retrospective analysis was performed on all patients who received lung-based SABR between May 2015 and September 2019 at Waikato Hospital, New Zealand. The study included both early stage lung cancer and lung oligometastases that measured less than 5cm. RESULTS: 102 patients received SABR to 116 lesions. Median follow-up was 19 months. The three-year rate of local control in the primary and metastatic cohorts was 85% and 82%, respectively. This reflects the three-year local control rate of 86% for primary lung cancer in the SPACE trial and the two-year local control rate of 81% for pulmonary oligometastases in a German study. Central primary lung cancer was associated with a higher risk of local recurrence (HR6.4 (1.3-31.5) p=0.02). The three-year progression-free survival rate in patients with early stage lung cancer and oligometastases was 56% and 26%, respectively. Maori patients with primary lung cancer had a significantly worse progression free survival (HR2.4 (1.1-5.1) p=0.03). There were no reported grade three toxicities. CONCLUSION: The use of lung-based SABR in a typical radiotherapy setting in New Zealand mirrors global outcomes.
Subject(s)
Lung Neoplasms/radiotherapy , Radiosurgery/methods , Aged , Female , Humans , Lung Neoplasms/pathology , Lung Neoplasms/secondary , Male , Middle Aged , Native Hawaiian or Other Pacific Islander , New Zealand , Radiosurgery/adverse effects , Retrospective Studies , Survival AnalysisABSTRACT
INTRODUCTION: The rising incidence of oropharyngeal squamous cell carcinoma (OPSCC) in New Zealand is due to an increase in the numbers of human papilloma virus (HPV)-associated OPSCC. We evaluated the impact of positive p16 immunohistochemistry, as a surrogate for HPV positivity, on OPSCC outcomes after primary intensity-modulated radiotherapy (IMRT) with or without concurrent chemotherapy. METHODS: Retrospective review was undertaken of electronic medical records of 90 patients with OPSCC who received primary IMRT with or without chemotherapy between 2008 and mid-2015 at the Regional Cancer Centre, Waikato Hospital, Hamilton, New Zealand. RESULTS: Median age was 57.5 years. Immunohistochemistry for p16 was positive in 53 (59%) OPSCC while 37 (41%) had negative or unknown p16 status. Median radiotherapy dose was 70 Gy. Chemotherapy was administered to 78 (87%) patients, most receiving high-dose cisplatin. Nine patients had residual disease following treatment completion. Seven patients relapsed, and 26 died during the study period. Five patients with p16-positive OPSCC had persistent or recurrent disease. Actuarial 3-year locoregional control, disease-free survival, and overall survival for all patients were 80.7%, 74.7%, and 77.1%, respectively. Among p16-positive OPSCC patients, 3-year locoregional control, disease-free survival, and overall survival were 89.5%, 80.8%, and 90.9%, respectively. CONCLUSION: Outcomes after IMRT for OPSCC at Waikato Hospital are in line with the reported literature. Human papilloma virus-related OPSCC has better outcomes compared with patients with unknown or HPV-unrelated OPSCC. Trials are underway evaluating reduced intensity of treatment for HPV-related OPSCC.
