Israel Medical Association Journal

Background: Adjuvant radiotherapy for breast cancer reduces local recurrence and improves survival. In patients with left sided breast cancer, anterior heart position or medial tumor location may cause inadequate breast coverage due to heart shielding. Respiration gating using the Real-time Position Management (RPM) system enables pushing the heart away from the tangential fields during inspiration, thus optimizing the treatment plan.

Objectives: To compare breathing inspiration gating (IG) techniques with free breathing (FB), focusing on breast coverage.

Methods: The study comprised 49 consecutive patients with left sided breast cancer who underwent lumpectomy and adjuvant radiation. RPM was chosen due to insufficient breast coverage caused by an anterior heart position or medial lumpectomy cavity. FB and IG computed tomography simulations were generated for each patient. Breast (PTVbreast) and lumpectomy cavity (CTVlump) were defined as the target areas. Optimized treatment plans were created for each scan. A dosimetric comparison was made for breast coverage and heart and lungs doses.

Results: PTVbreast V95% and mean dose (Dmean) were higher with IG vs. FB (82.36% vs. 78.88%, P = 0.002; 95.73% vs. 93.63%, P < 0.001, respectively). CTVlump V95% and Dmean were higher with IG (98.87% vs. 88.92%, P = 0.001; 99.14% vs. 96.73%, P = 0.003, respectively). The cardiac dose was lower with IG. The IG left lung Dmean was higher. No statistical difference was found for left lung V20.

Conclusions: In patients with suboptimal treatment plans due to anterior heart position or medial lumpectomy cavity, RPM IG enabled better breast/tumor bed coverage and reduced cardiac doses.

Background: Stereotactic ablative radiation therapy (SABR) is the application of a very high radiation dose to a small treatment volume. It is the new standard of care in medically inoperable early-stage lung cancer. 

Objectives: To report the outcomes of SABR in stage I lung cancer at Sheba Medical Center since its introduction in 2009.

Methods: We conducted a retrospective chart review of patients with stage I lung cancer treated during the period 2009–2015. Survival status was retrieved from the electronic medical records and confirmed with the national registry. Local failure was defined as increased FDG uptake on PETCT scan within a 2 cm radius of the treated region. Toxicity was estimated from medical records and graded according to common toxicity criteria for adverse events (CTCAE) version 4.03. Overall survival and local control were estimated by the Kaplan-Meier method.

Results: During the study period 114 patients were treated for 122 stage I lung cancer lesions. Median follow-up time was 27 months (range 8.2–69.5 months), median age was 76 years. Eighty-two percent of the tumors were stage IA (size ≤ 3 cm). Median survival was 46 months; estimated 3 year overall survival was 59% (95%CI 47–69%) and local control was 88% (95%CI 78–94%). Toxicity included chest wall pain in 8.4% of patients, rib fracture in 0.9%, grade 1–2 pneumonitis in 12%, grade 3 in 12% and grade 5 (death) in 0.9%.

Conclusions: SABR has been successfully implemented at Sheba Medical Center for the treatment of stage I lung cancer in inoperable patients. It is associated with excellent local control, minor toxicity and an acceptable overall survival.

 

Objectives: To report the experience at the first Israeli Linear Accelerator Radiosurgery Unit in the management of 44 patients with acoustic neurinomas.

Methods: We analyzed the clinical records and imaging studies of all patients undergoing radiosurgery for acoustic neurinomas between 1993 and 1997, and quanitified the changes in tumor volume, hearing status, and facial and trigeminal nerve function. The contribution of radiation dose and original tumor volume upon those variables was also studied.

Results: At a mean follow-up of 32 months (range 12–60), 98% of the tumors were controlled (75% had shrunk; 23% had stable volume). The actuarial hearing preservation rate was 71%. New transient facial neuropathy developed in 24% of the patients, persisting in mild degrees in 8%. Neuropathy correlated primarily with tumor volume. Tumors with volumes 4 ml were at high risk when marginal radiation doses were 1,400 cGy. Dose reduction to a maximum of 1,400 cGy produced no neuropathies in the last 20 patients, still preserving tumor control rates.

Conclusions: Radiosurgery is an effective and cost-efficient therapeutic modality for newly diagnosed acoustic neurinomas in the elderly or medically infirm population, and for all residual or recurrent tumors after conventional surgery.