User login
TOPLINE:
METHODOLOGY:
- Arrhythmia — with AF being the most common type — affects roughly 11% of patients following lung cancer RT.
- Given RT’s recognized impact on cardiac tissues over time, researchers hypothesized that the dosage affecting pulmonary veins might contribute to the observed increased rates of AF after RT.
- To investigate, researchers looked back at 420 patients with NSCLC (52% women, median age 70) undergoing definitive RT (± chemo) with modern planning techniques at 55 Gy in 20 once-daily fractions over 4 weeks.
- Most patients underwent treatment planning using volumetric modulated arc therapy (50%) or static gantry intensity-modulated RT (20%). Chemotherapy was administered in a minority of cases (33%).
- Pulmonary veins were contoured on planning CT scans, and dose metrics were calculated. The association between pulmonary veins dose and incidence of new AF was evaluated, with AF verified by a cardiologist.
TAKEAWAY:
- Out of the entire cohort, 26 patients (6%) developed AF a median of 13 months after treatment. All cases of AF were grade 3 except for two grade 4 events.
- Radiation dose to the left and right pulmonary veins was significantly associated with incident AF. Dose volumes most strongly associated with AF were ≥ 55 Gy (V55) on the left and ≥ 10 Gy (V10) on the right.
- The risk for AF increased by 2% per percentage point increase in the left pulmonary veins V55 and 1% in the right pulmonary veins V10. The associations were statistically significant after accounting for cardiovascular factors and risk for death risk.
- The area under the curve for prediction of AF events was 0.64 (P = .02) for the left pulmonary veins V55 and 0.61 (P = .03) for the right pulmonary veins V10. The optimal thresholds for predicting AF were 2% and 54%, respectively.
IN PRACTICE:
“The implications of these data are that actively sparing these structures could reduce the incidence of [AF], and where this is not possible, patients identified as being at high risk of AF could undergo active screening during follow-up,” the researchers said, adding that further validation of these findings should take place before implementation.
SOURCE:
The study, with first author Gerard M. Walls, MB, MRCP, Patrick G Johnston Centre for Cancer Research, Queen’s University Belfast, Belfast, Northern Ireland, was published online on January 4 in Radiotherapy and Oncology .
LIMITATIONS:
This was a single-center, retrospective study with a small number of AF events. The study may have underestimated the relationship between pulmonary vein irradiation and new AF events. The findings needed validation in larger datasets.
DISCLOSURES:
The study had no commercial funding. The authors declared no conflicts of interest.
A version of this article appeared on Medscape.com.
TOPLINE:
METHODOLOGY:
- Arrhythmia — with AF being the most common type — affects roughly 11% of patients following lung cancer RT.
- Given RT’s recognized impact on cardiac tissues over time, researchers hypothesized that the dosage affecting pulmonary veins might contribute to the observed increased rates of AF after RT.
- To investigate, researchers looked back at 420 patients with NSCLC (52% women, median age 70) undergoing definitive RT (± chemo) with modern planning techniques at 55 Gy in 20 once-daily fractions over 4 weeks.
- Most patients underwent treatment planning using volumetric modulated arc therapy (50%) or static gantry intensity-modulated RT (20%). Chemotherapy was administered in a minority of cases (33%).
- Pulmonary veins were contoured on planning CT scans, and dose metrics were calculated. The association between pulmonary veins dose and incidence of new AF was evaluated, with AF verified by a cardiologist.
TAKEAWAY:
- Out of the entire cohort, 26 patients (6%) developed AF a median of 13 months after treatment. All cases of AF were grade 3 except for two grade 4 events.
- Radiation dose to the left and right pulmonary veins was significantly associated with incident AF. Dose volumes most strongly associated with AF were ≥ 55 Gy (V55) on the left and ≥ 10 Gy (V10) on the right.
- The risk for AF increased by 2% per percentage point increase in the left pulmonary veins V55 and 1% in the right pulmonary veins V10. The associations were statistically significant after accounting for cardiovascular factors and risk for death risk.
- The area under the curve for prediction of AF events was 0.64 (P = .02) for the left pulmonary veins V55 and 0.61 (P = .03) for the right pulmonary veins V10. The optimal thresholds for predicting AF were 2% and 54%, respectively.
IN PRACTICE:
“The implications of these data are that actively sparing these structures could reduce the incidence of [AF], and where this is not possible, patients identified as being at high risk of AF could undergo active screening during follow-up,” the researchers said, adding that further validation of these findings should take place before implementation.
SOURCE:
The study, with first author Gerard M. Walls, MB, MRCP, Patrick G Johnston Centre for Cancer Research, Queen’s University Belfast, Belfast, Northern Ireland, was published online on January 4 in Radiotherapy and Oncology .
LIMITATIONS:
This was a single-center, retrospective study with a small number of AF events. The study may have underestimated the relationship between pulmonary vein irradiation and new AF events. The findings needed validation in larger datasets.
DISCLOSURES:
The study had no commercial funding. The authors declared no conflicts of interest.
A version of this article appeared on Medscape.com.
TOPLINE:
METHODOLOGY:
- Arrhythmia — with AF being the most common type — affects roughly 11% of patients following lung cancer RT.
- Given RT’s recognized impact on cardiac tissues over time, researchers hypothesized that the dosage affecting pulmonary veins might contribute to the observed increased rates of AF after RT.
- To investigate, researchers looked back at 420 patients with NSCLC (52% women, median age 70) undergoing definitive RT (± chemo) with modern planning techniques at 55 Gy in 20 once-daily fractions over 4 weeks.
- Most patients underwent treatment planning using volumetric modulated arc therapy (50%) or static gantry intensity-modulated RT (20%). Chemotherapy was administered in a minority of cases (33%).
- Pulmonary veins were contoured on planning CT scans, and dose metrics were calculated. The association between pulmonary veins dose and incidence of new AF was evaluated, with AF verified by a cardiologist.
TAKEAWAY:
- Out of the entire cohort, 26 patients (6%) developed AF a median of 13 months after treatment. All cases of AF were grade 3 except for two grade 4 events.
- Radiation dose to the left and right pulmonary veins was significantly associated with incident AF. Dose volumes most strongly associated with AF were ≥ 55 Gy (V55) on the left and ≥ 10 Gy (V10) on the right.
- The risk for AF increased by 2% per percentage point increase in the left pulmonary veins V55 and 1% in the right pulmonary veins V10. The associations were statistically significant after accounting for cardiovascular factors and risk for death risk.
- The area under the curve for prediction of AF events was 0.64 (P = .02) for the left pulmonary veins V55 and 0.61 (P = .03) for the right pulmonary veins V10. The optimal thresholds for predicting AF were 2% and 54%, respectively.
IN PRACTICE:
“The implications of these data are that actively sparing these structures could reduce the incidence of [AF], and where this is not possible, patients identified as being at high risk of AF could undergo active screening during follow-up,” the researchers said, adding that further validation of these findings should take place before implementation.
SOURCE:
The study, with first author Gerard M. Walls, MB, MRCP, Patrick G Johnston Centre for Cancer Research, Queen’s University Belfast, Belfast, Northern Ireland, was published online on January 4 in Radiotherapy and Oncology .
LIMITATIONS:
This was a single-center, retrospective study with a small number of AF events. The study may have underestimated the relationship between pulmonary vein irradiation and new AF events. The findings needed validation in larger datasets.
DISCLOSURES:
The study had no commercial funding. The authors declared no conflicts of interest.
A version of this article appeared on Medscape.com.