Radiotherapy for mediastinal lymphoma in breath hold using surface monitoring and nasal high flow oxygen: Clinical experiences and breath hold stability

PURPOSE

In this study we describe the clinical introduction and evaluation of radiotherapy in mediastinal lymphoma in breath hold using surface monitoring combined with nasal high flow therapy (NHFT) to prolong breath hold duration.

MATERIALS AND METHODS

11 Patients with mediastinal lymphoma were evaluated. 6 Patients received NHFT, 5 patients were treated in breath hold without NHFT. Breath hold stability as measured by a surface scanning system was evaluated, as well as internal movement based on cone beam computed tomography (CBCT) before and after treatment. Based on internal movement, margins were determined. In a parallel planning study we compared free breathing plans with breath hold plans using the determined margins.

RESULTS

Average inter breath hold stability was 0.6 mm for NHFT treatments, and 0.5 mm for non-NHFT treatments (p > 0.1). Intra breath hold stability was 0.8 vs. 0.6 mm (p > 0.1) on average. Using NHFT, average breath hold duration increased from 34 s to 60 s (p < 0.01). Residual CTV motion derived from CBCTs before and after each fraction was 2.0 mm for NHFT vs 2.2 mm for non-NHFT (p > 0.1). Combined with inter-fraction motion, a uniform mediastinal margin of 5 mm appears to be sufficient. In breath hold, mean lung dose is reduced by 2.6 Gy (p < 0.001), while mean heart dose is reduced by 2.0 Gy (p < 0.001).

CONCLUSION

Treatment of mediastinal lymphoma in breath hold is feasible and safe. The addition of NHFT approximately increases breath hold durations with a factor two while stability is maintained. By reducing breathing motion, margins can be decreased to 5 mm. A considerable dose reduction in heart, lungs, esophagus, and breasts can be achieved with this method.

Anthracycline exposure and breast cancer risk in female Hodgkin lymphoma survivors

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Background: Female Hodgkin lymphoma (HL) survivors treated with chest radiotherapy (RT) at a young age have a strongly increased risk of breast cancer (BC). Recently concern has been raised that anthracyclines may also increase BC risk, based on studies in childhood cancer survivors with/without a history of chest RT. So far, the association between anthracyclines and BC risk has not been examined in cancer survivors treated at adolescent/adult ages. Now that RT dose and volumes are decreasing, the potential contribution of anthracyclines to BC risk is an important issue. Methods: We assessed BC risk in a cohort of 2314 female 5-year HL survivors, treated at ages 15-50 years and diagnosed between 1965 and 2008 in 20 Dutch hospitals. Treatment factors were time-dependently included in the analysis, focusing on the effect of anthracycline exposure on BC risk. Results: After a median follow-up of 18.8 years, 258 women developed invasive BC or ductal carcinoma in situ as a subsequent malignancy. The 30-year cumulative incidence was 15.0% (95% Confidence Interval (CI) 12.8-17.4%). Mantle field RT (or other RT involving both axillae) was associated with increased risk of BC (Hazard ratio (HR) 1.9; 95% CI 1.2-2.8) compared to no supradiaphragmatic RT or RT to the neck only (Table 1). Gonadotoxic treatment (>4.2 g/m2 procarbazine or pelvic RT) significantly decreased this risk. In a multivariable analysis, anthracycline exposure was associated with increased BC risk (HR 1.8; 95% CI 1.3-2.5) in patients who received a cumulative dose of >200 mg/m2. Among patients exposed to gonadotoxic treatment, the HR of BC associated with >200mg/m2 anthracyclines was 3.8 (95% CI 2.0-7.2), with a trend for higher risk with higher anthracycline dose (HR 1.58 per 100mg/m2 anthracycline, p<0.001). Conclusions: Our results suggest an association of anthracyclines with BC risk in HL survivors. Also when accounting for the protective effect of gonadotoxic treatment on RT-associated BC risk, anthracyclines significantly contributed to a higher BC risk.[Table: see text]