The Effect of Deep Inspiration Breath-Hold Technique on Right Coronary Artery, Heart, and Liver Doses in Right Breast Cancer Radiotherapy

Purpose/Objective(s): The deep inspiration breath-hold (DIBH) approach has been thoroughly researched with the aim of reducing radiation exposures to normal tissues in breast cancer patients. Although heart and lung toxicity are widely addressed in many literature, radiation associated liver toxicity and dose constraints for the right coronary artery (RCA)are no twell studied in relation to breast radiotherapy. Additionally, very few studies have investigated the relationship between doses to cardiac substructures. This study aimed to determine the effect of the DIBH technique on the right coronary artery (RCA) region, cardiac substructures, and liver dose in right breast cancer irradiation. Materials/Methods: Between January 2022 and December 2022, thirty-five right breast cancer patients who previously received breast-surgery underwent computed tomography (CT) simulation with both free-breathing (FB) and DIBH techniques. Patients were contoured by a radiation oncologist on the scans using the Treatment Planning System. For cardiac substructures, reference atlas contours were used for accurate delineation and to reduce interobserver variation. Each patient underwent two treatment plans for both the DIBH and FB datasets.The plan comprised the FB and DIBH techniques, and the doses to the cardiac substructures, ipsilateral lung, RCA region, and liver were compared using atwo-tailed paired t-test. Radiotherapy was delivered with a Linac with the prescription dose of 50Gy in 25 fractions. Results: ForbothFBandDIBHirradiationgroups, the mean radiation doses to the ipsilateral lung, heart, and RCA region in patients with FB and DIBH techniques were; 14.67Gy, 2.33Gy, 4.88Gy and 12.05Gy, 1.34Gy and 3.29Gy respectively. The mean radiation doses to the cardiac substructures; for the left ventricle, right ventricle, left atrium,and right atrium for the FB were 1.08Gy, 1.79Gy, 4.11Gy, and for DIBH, 0.49Gy, 1.49Gy, 0.95Gy, and 2.61Gy, respectively. For the DIBH group, the liver maximum dose (p&lt;0.01), right lung mean dose (p=0.001), heart maximum dose (p=0.009), RCA mean dose (p=0.020), RCA maximum dose(p=0.008), RCA V5 dose(p=0.035), right atrium maximum dose (p=0.009) and right ventricle mean dose (p=0.040) were significantly lower than in patients treated in the non-gated group. Conclusion: DIBH resulted in considerable displacement of the liver away from the high-dose target region, such that the volume of liver in the high dose region was reduced. Additionally, the use of the DIBH technique in right breast cancer irradiation effectively reduces the radiation doses to the cardiac substructures, such as the left ventricle, right ventricle, left atrium, right atrium, RCA region, and lungs. DIBH could lead to substantial sparing of these structures with the right breast cancer radiotherapy. Future prospective studies are required to determine whether improvements to dose-distribution will translate in to improved toxicity outcomes.</p

MEME KANSERİ TANILI HASTALARDA KLİNİK (ANATOMİK) VE PROGNOSTİK EVRE GRUPLARININ SAĞKALIMA ETKİSİ-TROD 06-019

Amaç:&nbsp;Meme kanseri tanılı hastalarda klinik (anatomik) ve biyolojik belirteçlerin eklenmesi ile elde edilen prognostik evre grupları arasındaki farkları, evre değişim oranını ve evre değişiminin sağkalıma etkisini saptamaktır.Gereç Yöntem:&nbsp;Tüm merkezlere çalışma protokolü gönderilmiştir. Dört merkez çalışmaya hasta girişi yapmıştır. Biyobelirteçleri (hormon reseptörleri ve c-erb B2) eksiksiz olarak bilinen, neoadjuvan tedavi almamış, tanıda metastatik olmayan 1470 hasta çalışmaya dahil edilmiş ve geriye dönük olarak değerlendirilmiştir. Anatomik evrelemede patolojik tümör boyutu (pT), lenf nodu durumu (pN) dikkate alınırken, prognostik evrelemede AJCC 8. versiyona göre biyobelirteçlerin evrelemeye katılması ile evre grupları belirlenmiştir. Sağkalım analizleri Kaplan- Meier yöntemi, genel sağkalım (GSK) ve hastalıksız sağkalım (HSK) için değişkenlerin anlamlılık analizi log-rank testi ile hesaplanmıştır.Bulgular:&nbsp;Hastalarda median yaş 52 (20-88) olup, 865 olgu (%58.8) postmenapozal dönemdedir. Histopatolojik tanı 859 hastada invaziv duktal karsinom (İDK)’dur (%58.4). Aksilla 765 hastada negatif (N0) (%52.1), 438 olguda N1mic-N1a’dır (%29.8). Tümör derecesi 200 hastada derece I (%13.6), 812 derece II (%55.2), 452 derece III (%30,7) şeklindedir. ER; 1247 hastada pozitif (%84.8), 223 olguda negatif (%15.2), PR; 1178 hastada pozitif (%80.1), 292 hastada negatiftir (%19.9). Her2-neu; 1263 hastada negatif (%85.9), 207 hastada pozitiftir(%14.1). Toplam 777 hastada evre değişimi saptanırken (%52.9), 693 hastada evre değişimi olmamıştır (%47.1). Anatomik evreleme ile karşılaştırıldığında, prognostik evre gruplarında %46.4 olguda alt evreye, %6.5 olguda üst evreye değişim saptanmıştır. Ortanca izlem süresi 80 (6-237) aydır. Hastalarda 5 ve 10 yıllık GSK ve HSK değerleri sırasıyla; %73.7, %44.3 ve %91.9, %86.3 şeklindedir. GSK için çok değişkenli analizde yaş (p&lt;0.001), tümör derecesi (p&lt;0.001), ER reseptör durumu (p&lt;0.001), PR reseptör durumu (p&lt;0.001), cerbB2 reseptör durumu (p=0.025); HSK için çok değişkenli analizde yaş (p=0.027), tümör derecesi (p=0.005) anatomik evre (p&lt;0.001) ve evre atlaması (p=0.001) anlamlı değişkenlerdir.Sonuç:&nbsp;Anatomik evrelemeye göre çoğunluğunu erken evre olguların oluşturduğu hasta grubumuzda hormon reseptörleri ve c-erb B2 reseptörü durumu GSK ve HSK etkileyen bağımsız değişkenlerdir. Prognostik evrelemede evre atlaması olması HSK’ı etkileyen bağımsız prognostik faktör olarak öne çıkmaktadır. Anatomik evrelemeye göre biyobelirteçlerin durumu prognozu daha iyi belirlemektedir.</p

The Effect of Clinical (Anatomical) and Prognostic Stage Groups on Survival in Patients Diagnosed with Breast Cancer: MULTI-Center Study Results, TROD Breast Cancer Study Group

Purpose/Objective(s): The American Joint Committee on Cancer(AJCC) anatomic stage groups have arguably been the most powerful method in&nbsp; predicting breast cancer outcomes. In the present study, we aimed to determine the differences between anatomical stage and clinical prognostic stage groups,which were obtained by adding biological markers such as histologic tumor grade, estrogen receptor(ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 status to patients diagnosed with breast cancer, the rate of change in stage, and the effect of stage change on survival. Materials/Methods:The study protocol was sent to all radiation oncology centers in Turkiye. Four centers enrolled their patients in the study. Atotal of 1470 stageI-III breast cancer patients with complete information on biological markers (histologic tumor grade, hormone receptor, andc-erbB2 receptor status), haven’t been treated with neoadjuvant therapy were included to the study and evaluated retrospectively. The 8theditionof AJCC consolidated biological markers in to clinical prognostic stage groups. Kaplan-Meier curves were used to estimate survival. The log-rank test was used to compare the difference between groups.The Cox proportional-hazards regression model was used to determine the association between anatomic-prognostic stage, disease-free survival(DFS), and overall survival(OS). Results:The median follow-up time was 82(6-237) months. Median age of the patients was 52years (20-88) and 865 cases (58.8%) were in the postmenopausal period. The axillary lymph node status was negative (N0) in 765 patients (52.1%).Tumor grade was grade I in200patients (13.6%), grade II in 812 patients (55.2%) and grade III in 452 patients (30.7%). Estrogen receptor status was positive in 1247 patients (84.8%), PR status was positive in 1178 patients and Her2-neu status was positive in 207 patients (14.1%). A stage change has been identified in a total of 777 patients (52.9%).Compared with the anatomic stage groups,&nbsp; the clinical prognostic stage groups assigned 46.4% cases lower and 6.5% cases higher stage. Five-and ten-year OS and DFS rates of the patients are 73.7%,44.3%and91.9%,86.3%respectively. Age (p&lt;0.001), tumor grade (p&lt;0.001), ER status (p&lt;0.001), PR status (p&lt;0.001),cerbB2 receptor status(p=0.025) were found to be statistically significant variables in multi variable analysis for OS. For DFS, multivariable analysis showed that age (p=0.027), tumor grade (p=0.005), anatomical stage (p&lt;0.001) and assigned to higher stage (p=.001) were statistically significant variables.Conclusion: Hormonereceptors and c-erbB2 receptor status are independent variables which impact OS and DFS in our patient group, which is mostly consisted of early-stage cases according to anatomical stage. In&nbsp;prognostic staging, upstaging stands out as an independent prognostic factor for DFS. The 8th edition of AJCC prognostic stage groups determines the prognosis much better in our patient cohort.</p