Increased use of partial-breast irradiation has not improved radiotherapy utilization for early-stage breast cancer

Considering Lumpectomy Cavity PTV Expansions: Characterization of Intrafraction Lumpectomy Cavity Motion

PURPOSE

Accelerated partial breast irradiation and lumpectomy cavity boost radiation therapy plans generally use volumetric expansions from the lumpectomy cavity clinical target volume to the planning target volume (PTV) of 1 to 1.5 cm, substantially increasing the volume of irradiated breast tissue. The purpose of this study was to quantify intrafraction lumpectomy cavity motion during external beam radiation therapy to inform the indicated clinical target volume to PTV expansion.

METHODS AND MATERIALS

Forty-four patients were treated with a whole breast irradiation using traditional linear accelerator-based radiation therapy followed by lumpectomy cavity boost using magnetic resonance (MR)-guided radiation therapy on a prospective registry study. Two-dimensional cine-MR images through the center of the surgical cavity were acquired during each boost treatment to define the treatment position of the lumpectomy cavity. This was compared with the reference position to quantify intrafraction cavity motion. Free-breathing technique was used during treatment. Clinical outcomes including toxicity, cosmesis, and rates of local control were additionally analyzed.

RESULTS

The mean maximum displacement per fraction in the anterior-posterior (AP) direction was 1.4 mm. Per frame, AP motion was <5 mm in 92% of frames. The mean maximum displacement per fraction in the superior-inferior (SI) direction was 1.2 mm. Per frame, SI motion was <5 mm in 94% of frames. Composite motion was <5 mm in 89% of frames. Three-year local control was 97%. Eight women (18%) developed acute G2 radiation dermatitis. With a median follow-up of 32.4 months, cosmetic outcomes were excellent (22/44, 50%), good (19/44, 43%), and fair (2/44, 5%).

CONCLUSIONS

In approximately 90% of analyzed frames, intrafraction displacement of the lumpectomy cavity was <5 mm, with even less motion expected with deep inspiratory breath hold. Our results suggest reduced PTV expansions of 5 mm would be sufficient to account for lumpectomy cavity position, which may accordingly reduce late toxicity and improve cosmetic outcomes.

Disparities in Breast-Conserving Therapy for Non-Hispanic American Indian/Alaska Native Women Compared with Non-Hispanic White Women

BACKGROUND

Little is known about the surgical patterns of American Indian/Alaska Native (AI/AN) breast cancer patients. The purpose of this study is to determine whether there are disparities in breast cancer surgery and radiation therapy between non-Hispanic AI/AN (NH-AI/AN) women and non-Hispanic White (NHW) women.

METHODS

Data from the National Program of Cancer Registries of the Centers for Disease Control and Surveillance, Epidemiology, and End Results were used for this cross-sectional study. Female patients with invasive breast cancer diagnosed 2010-2015 were stratified by race/ethnicity, surgical procedure, radiation, and region. Percentage distributions of mastectomy and lumpectomy were compared overall and by region and stage.

RESULTS

From 2010 to 2015 there were 3292 NH-AI/AN women and 165,225 NHW women diagnosed with breast cancer. For early stage (AJCC stage 1 and 2), NH-AI/AN women had overall significantly higher percentage of mastectomy (41% vs 34.4%, p < 0.001) and significantly lower percentage of lumpectomy (59% vs 65.6%) compared with NHW women, without significant differences in post-lumpectomy radiation (71% vs 70%). There were regional variations, notably in the Northern Plains, where the percentage of mastectomy for early-stage disease was 48.9% for NH-AI/AN women versus 35.9% for NHW women, and in Alaska with 47% for NH-AI/AN women versus 33.3% for NHW women (p < 0.001). There were no overall significant differences in type of surgery or radiation for late-stage disease between groups.

CONCLUSION

This is the first study to show disparities in surgical management of NH-AI/AN women with breast cancer. For early-stage disease, NH-AI/AN women undergo a higher percentage of mastectomy. Future clinical directions could focus on the factors that drive awareness, decision-making, and access to breast conservation.

The enablers, barriers and preferences of accessing radiation therapy facilities in the rural developed world - a systematic review

BACKGROUND

Utilisation of radiation therapy for regional Australia and around the world has been the focus of much health policy the last decade. Radiation therapy centres have been built in Australian regional and rural areas to improve access to radiation therapy and reduce the tyranny of distance as a barrier to access. After this the enablers, barriers and perceptions of patients has been evaluated to determine utilisation once centres have been built. Thisreview looks the impact of rural radiation services in the developed world, barriers and enablers of establishing a rural radiation centre, and patients' and service providers' perspectives and preferences around the uptake of rural radiation therapy.

METHODS

Online search of peer reviewed literature was undertaken using MeSH terms relating to the topic. Inclusion criteria were regional radiation therapy centres in developing countries, any year of publication, in English, and qualitative or quantitative methodologies. Articles were reviewed by two authors with conflicts discussed with a third.

RESULTS

Twenty three studies addressed the theme directly. Distance barriers have been overcome by building regional centres and health economic burden was lower for government service providers with this strategy. However distance still plays an important role in influencing uptake of radiation therapy. Cultural expectations, influence of the family doctor and perception of care was influential. Carer support, duration of displacement from home, financial impact of the required care and seasonal weather were practical factors on a patient's decision.

CONCLUSIONS

Regional radiation therapy centres have improved access to radiation therapy in developing countries. However the complex nuances between socio-economic, cultural and health system factors that influence regional patient's decision making bears further consideration, as distance is not the only issue.