Left Breast Cancer Research Articles

Influence of minimum segment width on intensity-modulated radiotherapy plan for left-sided breast cancer after breast conserving surgery.

To research the influence of the minimum segment width (MSW) on intensity-modulated radiotherapy (IMRT) plan for left breast cancer after breast conserving surgery and provide a reference for plan optimization. Ten patients with left-sided early-stage breast cancer after breast-conserving surgery (BCS) were selected for postoperative radiotherapy. The Monaco 5.11 treatment planning system (TPS) was used, and the optimization parameters of the plan were fixed, while MSW were set to 0.5, 1, 1.5, and 2 cm, and four 5 field-IMRT plans were designed for every patient. The plan quality and execution efficiency of each plan were compared, including planning target volume (PTV) dose, organs at risk (OAR) dose, segments number (SN), monitor units (MU), delivery time (DT), and dose verification results. With the increase of the MSW, the dose indexes of the OAR were similar (P > .05). The D2%, D98%, and D50% of the PTV gradually deviated from the prescription dose, and the uniformity gradually deteriorated (P < .05). The gamma passing rates (GPR) of dose verification and the dose deviation of the PTV were similar (P > .05). The SN, MU, and DT gradually decreased (P < .05), but the amplitude change caused by each increase of 0.5 cm gradually decreased, the decrease of 0.5 to 1 cm was the largest, reaching 16.41%, 21.25%, and 0.35 minutes, respectively, while the 3 values of 1.5 and 2 cm were close. When using Monaco 5.11 TPS to design IMRT plan for left breast cancer after BCS, 1.5 cm MSW could ensure better dose coverage and uniformity of the PTV, as little as possible exposure dose to the OAR, and high dose verification accuracy. The SN, MU, and DT were significantly reduced, and the treatment efficiency was improved.

Cardiac protective techniques in left breast radiotherapy: rapid selection criteria for routine clinical decision making

ObjectiveIn left breast radiotherapy (RT) desired heart doses may be achieved without heart-sparing RT techniques in some patients. We aimed to examine the existence of predictive factors and cutoff points to determine which patients are the main candidates for heart-sparing RT techniques.Material and methodDosimetric data for left breast cancer was examined. RT plans were made at conventional doses to the breast and peripheral lymph nodes. Statistical analyses were performed using SPSS 22.0 (SPSS Inc., IBM Corp., Armonk, NY).Result114 cases were evaluated by ROC (Receiver operating characteristic) analysis in the breast-conserving surgery (BCS) and mastectomy groups. While only left lung volume (AUC: 0.74, 95% CI 0.61–0.87, p = 0.002) was significant in BCS cases, in cases with mastectomy, left lung volume (AUC: 0.81, 95% CI 0.69–0.94, p = 0.002) and lung/heart volume ratio (AUC: 0.83, 95% CI 0.70–0.96, p = 0.001) had a significant relationship with the relevance of heart doses. The cutoff point of 1.92 was selected for the lung/heart volume ratio for the mastectomized patients. Moreover, the cutoff point 1154 cc and 1208 cc was determined for the left lung volume for the BCS and mastectomized patients, respectively.ConclusionVarious cutoff points in left breast RT can be used to predict whether RT plans will meet QUANTEC (Quantitative Analysis of Normal Tissue Effects in the Clinic) heart dose limits. Evaluating only these few cutoff points before planning makes it possible to eliminate 70% of patients with BCS and 40% of patients with mastectomy from respiratory-controlled methods, which require time and effort. Patients with lung volume and lung/heart volume ratio smaller than the cutoff values can be considered primary candidates for heart-sparing techniques.

Implementation and evaluation of an iterative-based algorithm for automatic beam angle optimization in breast cancer treatment planning

IntroductionA beam angle optimization (BAO) algorithm was developed to evaluate its clinical feasibility and investigate the impact of varying BAO constraints on breast cancer treatment plans. Materials and MethodsA two-part study was designed. In part 1, we retrospectively selected 20 patients treated with radiotherapy after breast-conserving surgery. For each patient, BAO plans were designed using beam angles optimized by the BAO algorithm and the same optimization constraints as manual plans. Dosimetric indices were compared between BAO and manual plans. In part 2, fifteen patients with left breast cancer were included. For each patient, three distinct cardiac constraints (mean heart dose < 5 Gy, 3 Gy or 1 Gy) were established during the BAO process to obtain three optimized beam sets which were marked as BAO_H1, BAO_H3, BAO_H5, respectively. These sets of beams were then utilized under identical IMRT constraints for planning. Comparative analysis was conducted among the three groups of plans. ResultsFor part 1, no significant differences were observed between BAO plans and manual plans in all dosimetric indices, except for ipsilateral lung V5, where BAO plans performed slightly better than manual plans (35.5% ± 5.6% vs 36.9% ± 4.3%, p = 0.034). For part 2, Stricter BAO heart constraints resulted in more perpendicular beams. However, there was no significant difference between BAO_H1, BAO_H3 and BAO_H5 with the same IMRT constraint in the heart dose. Meanwhile, the left lung dose was increased while the right breast and lung doses were decreased with stricter heart constraints in BAO. When mean heart dose < 5 Gy in IMRT constraint, the mean dose to the right lung was decreased from 0.46 Gy for BAO_H5 to 0.33 Gy for BAO_H1 (p = 0.027). ConclusionsThe BAO algorithm can achieve quality plans comparable to manual plans. IMRT constraints dominate the final plan dose, while varying BAO constraints alter the trade-off among structures, providing an additional degree of freedom in planning design.

Active Breathing Coordinator reduces radiation dose to the stomach in patients with left breast cancer

Background/Purpose Gastric dose parameters comparison for deep inspiration breath-hold (DIBH) or free breathing (FB) mode during radiotherapy (RT) for left-sided breast cancer patients (LSBCPs) has not been investigated before. This study aimed to analyze the impact of Active Breath Coordinator (ABC)-DIBH technique on the dose received by the stomach during RT for LSBCPs and to provide organ-specific dosimetric parameters. Materials and methods The study included 73 LSBCPs. The dosimetric parameters of the stomach were compared between FB and DIBH mode. The correlation between the stomach volume and dosimetric parameters was analyzed. Results Compared to FB mode, statistically significant reductions were observed in gastric dose parameters in ABC-DIBH mode, including Dmax (46.60 vs 17.25, p < 0.001), D1cc (38.42 vs 9.60, p < 0.001), Dmean (4.10 vs 0.80, p < 0.001), V40Gy (0.50 vs 0.00, p < 0.001), V30Gy (6.30 vs 0.00, p < 0.001), V20Gy (20.80 vs 0.00, p < 0.001), V10Gy (51.10 vs 0.77, p < 0.001), and V5Gy (93.20 vs 9.60, p < 0.001). ABC-DIBH increased the distance between the stomach and the breast PTV when compared to FB, from 1.3 cm to 2.8 cm (p < 0.001). Physiologic decrease in stomach volume was not found from FB to ABC-DIBH (415.54 cm3 vs 411.61 cm3, p = 0.260). The stomach volume showed a positive correlation with V40Gy (r2 = 0.289; p < 0.05), V30Gy (r2 = 0.287; p < 0.05), V20Gy (r2 = 0.343; p < 0.05), V10Gy (r2 = 0.039; p < 0.001), V5Gy (r2 = 0.439; p < 0.001), Dmax (r2 = 0.269; p < 0.05) and D1cc (r2 = 0.278; p < 0.05) in FB mode. While in ABC-DIBH mode, most stomach dosimetric parameters were not correlated with gastric volume. Conclusions The implementation of ABC-DIBH in LSBCPs radiotherapy resulted in lower irradiation of the stomach. Larger stomach volume was associated with statistically significantly higher dose irradiation in FB mode. To reduce radiotherapy related side effects in FB mode, patients should be fast for at least 2 hours before the CT simulation and treatment.

Radiotherapy dosimetry and radiotherapy related complications of immediate implant-based reconstruction after breast cancer surgery.

The impact of immediate implant-based breast reconstruction (IBBR) on the delivery of radiotherapy plans remains controversial. This study aimed to compare the differences in radiotherapy dosimetry, complications of radiotherapy, and quality of life in patients who underwent modified radical mastectomy combined with or without IBBR. We retrospectively collected 104 patients with breast cancer who underwent intensity-modulated radiation therapy after modified radical mastectomy with IBBR (n =46) or not (n =58) from January 2017 to December 2021. The dosimetric differences in radiotherapy of planning target volume (PTV) and organs at risk and the differences in complications of radiotherapy between the two groups were compared. We also applied the functional assessment of cancer therapy-breast cancer (FACT-B) score to compare the difference in quality of life. The chi-square test and independent samples t-test were used to analyze the above data. IBBR group was associated with higher PTV volumes, PTV D98, V95, and lower PTV Dmean, D2 compared with the non-reconstruction group (P<0.05). IBBR group also had lower radiotherapy dosimetric parameters in the ipsilateral lung and the heart of left breast cancer patients. The differences in the rates of radiation pneumonia (RP) and radiation dermatitis (RD) between the two groups were not statistically significant (P > 0.05). Moreover, FACT-B scores at 6 months after radiotherapy in patients with IBBR were higher than those without reconstruction (P < 0.05). Patients with IBBR achieved better radiation dosimetry distribution and higher quality of life without more complications of radiotherapy.

Correlation of High-Sensitivity Cardiac Troponin I Values and Cardiac Radiation Doses in Patients with Left-Sided Breast Cancer Undergoing Hypofractionated Adjuvant Radiotherapy with Concurrent Anti-HER2 Therapy.

Anti HER2 therapy and left breast adjuvant radiation therapy (RT) can both result in cardiotoxicity. The aim of this study was to evaluate the influence of radiation dose on cardiac structures on the values of the early cardiotoxicity marker high-sensitivity cardiac troponin I (hscTnI) in patients with HER2-positive left breast cancer undergoing adjuvant concomitant antiHER2 therapy and radiotherapy, and to establish a correlation between the hscTnI values and cardiac radiation doses. Sixty-one patients underwent left breast hypofractionated radiotherapy in parallel with anti-HER2 therapy: trastuzumab, combined trastuzumab-pertuzumab or trastuzumab emtansine (T-DM1). The hscTnI values were measured prior to and upon completion of radiotherapy. A significant increase in hscTnI was defined as >30% from baseline, with the second value being 4 ng/L or higher. Dose volume histograms (DVH) were generated for the heart, left ventricle (LV) and left anterior descending artery (LAD). The hscTnI levels were corelated with radiation doses on cardiac structures. An increase in hscTnI values was observed in 17 patients (Group 1). These patients had significantly higher mean radiation doses for the heart (p = 0.02), LV (p = 0.03) and LAD (p = 0.04), and AUC for heart and LV (p = 0.01), than patients without hscTnI increase (Group 2). The patients in Group 1 also had larger volumes of heart and LV receiving 2 Gy (p = 0.01 for both) and 4 Gy (p = 0.02 for both). LAD differences were observed in volumes receiving 2 Gy (p = 0.03), 4 Gy (p = 0.02) and 5 Gy (p = 0.02). The increase in hscTnI observed in patients receiving anti-HER2 therapy after adjuvant RT was positively associated with radiation doses on the heart, LV and LAD.

THU643 Hyperandrogenism Caused By A Steroid Cell Tumor Of The Ovary In A Postmenopausal Woman

Abstract Disclosure: M.S. Myint: None. A. Pinero-Pilona: None. Introduction Steroid cell tumor-not otherwise specified (SCT-NOS) is a subtype of steroid cell tumors which, in turn, is a subtype of sex cord-stroma tumors of the ovary. SCTs are exceedingly rare, account for less than 0.1% of all ovarian tumors, can secrete androstenedione, α-hydroxyprogesterone, and testosterone, and cause hyperandrogenism. We present a case of SCT-NOS, which was revealed postoperatively and was associated with breast cancer. Clinical Case A 74-year-old postmenopausal woman presented approximately a year after the onset of hirsutism, frontal alopecia and an elevated serum total testosterone (TTST) 341 ng/dl (reference range 3 to 41 ng/dL) and free testosterone (FRTST) 10.5 pg/mL (reference range 0.0 to 4.2 pg/mL). She has no clitoromegaly, acne, striae, or changes in voice and no history of infertility or PCOS. Physical examination was significant for cushingoid appearance, frontal alopecia, and hirsutism on the face. Her estradiol level was 213 pg/mL (reference range 0 to 30 pg/mL), FSH and LH levels were in the postmenopausal range, 17-hydroxyprogesterone, DHEA-sulfate, androstenedione, and morning cortisol were normal. Pelvic ultrasonography and CT of the abdomen and pelvis did not reveal an adrenal or ovarian abnormality. We suspected an ovarian source and thus recommended bilateral oophorectomy due to the markedly elevated testosterone level and postmenopausal status. We also started spironolactone. Before setting up for surgery, she was diagnosed with invasive lobular left breast cancer and underwent surgery and radiotherapy. Then, she had bilateral salpingo-oophorectomy. After surgery, TTST dropped to 4 ng/dL and FRTST to 2 pg/mL. Her hyperandrogenic symptoms significantly subsided. Pathology revealed a 1.5 cm red-brown nodule within the left ovary. The nodule contains polygonal cells with vacuolated cytoplasm arranged in nests, cords, and sheets. Cells were positive in calretinin and inhibin and negative in Reinke crystal. A steroid cell tumor, NOS was confirmed. Pathologic features associated with aggressive clinical behavior were not present. Conclusion The incidence of SCT-NOS is highest in women of childbearing age but rare in postmenopausal women. There were only a few case reports of SCT-NOS, most of which are relatively larger and revealed on imaging. In our case, the imaging did not localize the tumor. Sex cord-stromal tumors are often not visualized on imaging. Failure to identify a tumor on imaging does not rule out the presence of a tumor. One should always rule out androgen-secreting tumors in cases of significantly high testosterone. When imaging fails to reveal a tumor, bilateral oophorectomy should be considered in postmenopausal women and an ovarian and adrenal venous sampling in women of childbearing age. It is worth doing so because hyperandrogenism is associated with an increased risk of endometrial and breast cancer. Presentation: Thursday, June 15, 2023

330P Effect of radiotherapy in deep inspiration in patients with left breast cancer: Does the size of the target area affect the dose for the most crucial organs at risk?

330P Effect of radiotherapy in deep inspiration in patients with left breast cancer: Does the size of the target area affect the dose for the most crucial organs at risk?

Focal laser photocoagulation for central serous chorioretinopathy in a patient receiving tamoxifen for breast cancer

Breast cancer is the most common cancer among females in Taiwan. Tamoxifen is an important adjuvant therapy for breast cancer. Although tamoxifen maculopathy has been reported in case series, typical central serous chorioretinopathy (CSCR) was reported only in one case. Here, we present a 67-year-old postmenopausal female with left triple-positive breast cancer who received an adjuvant low-dose tamoxifen regimen with 10 mg twice daily for 7 years. She developed presumed tamoxifen-related CSCR and was successfully treated by focal laser.

Dose DIBH Really Reduce the Subclinical Cardiac Acute Injury? Analysis of Clinical Real World from Our Institute

The study is aim to investigate whether Deep-inspirational breath-hold (DIBH), compared with free breathing (FB), could provide a short-term cardiac benefit in patients with early left breast cancer after breast-conserving surgery combined whole breast radiotherapy. A total of 78 patients with early stage left breast cancer treated with radiotherapy between 2021-2022 after breast-conserving surgery were enrolled. Among them, 32 cases were treated with DIBH technique and 46 cases were treated with free breathing. Patients with previous cardiac disease such as coronary artery disease were excluded. We performed myocardial enzymes, ECG, and ECHO in all patients within 2 weeks before, during, and 6 months after radiotherapy. The results of the two groups were compared using nonparametric tests and chi-square tests, and P < 0.05 indicated statistical significance. Where subclinical acute cardiac injury was defined as new above-normal myocardial enzymes and/or electrocardiographic ST-T or T-wave changes and/or ECHO abnormalities after the start of radiotherapy. The median follow-up of patients was 6 months and the mean age of patients was 52.3 years for FB and 44.9 years for DIBH. There were no significant differences in staging, molecular subtype, chemotherapy and endocrine therapy history. The proportion of subclinical acute cardiac injury was smaller in the DIBH group compared to the FB group (DIBH = 31/46 and FB = 28/32, p = 0.042). The most sensitive of the subclinical acute cardiac injury events were detected by myocardial enzymes rising, with cTnI (p = 0.034) and NT-proBNP (p = 0.023) appearing significantly lower in the DIBH patients during radiotherapy. The difference of cTnI between 2 groups at 6 months after radiotherapy became non-significant. In contrast, CK-MB was higher in DIBH compared with FB only 6 months after radiotherapy (p = 0.006). The differences in ECG and ECHO were not significant between the two groups. After breast-conserving surgery combined with radiotherapy for left early breast cancer, DIBH compared to FB reduces the proportion of acute subclinical cardiac injury that occurs with the most sensitive changes in myocardial enzymes. Subsequent studies will explore the relationship between the short-term subclinical injury and irradiated dose, as well as long term cardiac injury.

Analysis of Institutional DIBH Coaching Program for Surface Guided-DIBH Patients

Our institute has implemented a surface guided-DIBH (SG-DIBH) coaching program which involves consultation, pre-treatment (CT-sim) and treatment. We would like to analyze the effectiveness of the program. A total of 72 left breast cancer patients between 1st Apr 2022 to 9th Dec 2022 were registered for radiation treatment. During consultation, oncologist selected suitable patients based on the following criteria: a) age of 18-70; b) left breast cancer, right breast cancer with internal mammary nodes irradiation or dextrocardia; c) no lung/cardiac disease history & d) volunteer for SG-DIBH technique. The eligible patients were then trained by the coaching therapist using a teaching video and practiced at home. During CT simulation, patients were assessed according to the DIBH evaluation form. The evaluation components included patient's compliancy and understanding, the differences of lateral skin marking (free breathing, FB vs DIBH), duration of breath hold and reproducibility. Patients who passed the evaluation were scanned under both FB and DIBH for SG-DIBH treatment. IMRT-FFF 6 to 7 fields were planned. During SG-DIBH treatment, first 3 fractions and weekly CBCT were taken. Patients were encouraged to continue DIBH practice at home throughout whole course of the treatment and they were given 3 identical survey forms (5 questions) at the beginning, middle and end of treatment. The measure for the success of this coaching program would be number of breath-holds, duration of treatment time, treatment accuracy (CBCT matching) and survey results. There were 48 patients who were eligible for DIBH coaching program, however, only 24 patients had passed the coaching evaluation and 20 patients were treated with SG-DIBH technique successfully. The mean of number of breath-hold and treatment time was 7 times and 7.9 minutes. Total of 123 CBCT images were studied. The setup errors were (0.242±0.180) cm, (0.152±0.137) cm, (0.202±0.165) cm, (0.684±0.640) degrees, (0.816±0.767) degrees, (0.912±0.707) degrees in lateral, longitudinal, vertical, pitch, roll and yaw directions. According to the survey analysis, the number of times to practice at home decreased as the treatment went by. An improvement was seen in patients' self-evaluation in mastering DIBH technique with proper coaching program (from 60% to 90%). Patients' anxiety in performing DIBH were alleviated greatly towards the end of the treatment (from 47% to 15%). 100% of the patients were willing to go for DIBH treatment if given a second chance and additional suggestions claimed that professional clinical teams and coaching program were important for their DIBH treatment journey. A comprehensive DIBH coaching program can effectively identify SG-DIBH patient's suitability. Patient compliancy, treatment accuracy and treatment experience can be enhanced with good coaching program. The involvement of clinical team from consultation to pre-treatment and treatment stage is essential for a successful SG-DIBH treatment.

Application of Deep Inspiration Breath Hold Technique in Radiotherapy After Breast- Conserving Surgery for Left Breast Cancer and Its Improvement on Cardiac Dose

Objective: To analyze the application of deep inspiration breath hold technique in radiotherapy after breast-conserving surgery for left breast cancer and the improvement of cardiac dose. Methods: A total of 45 patients with left breast cancer treated in our hospital after breast-conserving surgery were selected, and the selection time was set from January 2020 to August 2022. All patients received radiotherapy. The right breast, heart, and lung volumes, and dose parameters of the heart, lungs, right breast, and left anterior descending coronary artery were compared under free breathing (FB) and deep inspiration breath hold (DIBH) technical modes. Results: The heart volume of the DIBH group was smaller than that of the FB group, and the left and right lung volumes were significantly larger than those of the FB group. In the DIBH group, the heart dose parameters V5, proper lung dose parameters, and left anterior descending coronary artery dose parameters were found lower than that of the FB group, and the differences were statistically significant (P &lt; 0.05). Conclusion: Compared with FB, the DIBH technique can reduce the heart’s size and increase the lung volume when used for radiotherapy after breast-conserving surgery for left breast cancer. It also reduces the dose to the heart, right lung, and left anterior descending coronary artery, thus protecting the heart and lungs.

Deep-learning Method for the Prediction of Three-Dimensional Dose Distribution for Left Breast Cancer Conformal Radiation Therapy

AimsAn increase in the demand of a new generation of radiotherapy planning systems based on learning approaches has been reported. At this stage, the new approach is able to improve the planning speed while saving a reasonable level of plan quality, compared with available planning systems. We believe that new achievements, such as deep-learning models, will be able to review the issue from a different point of view. Materials and methodsThe data of 120 breast cancer patients were used to train and test the three-dimensional U-Res-Net model. The network input was computed tomography images and patients' contouring, while the patients' dose distribution was addressed as the output of the model proposed. The predicted dose distributions, created by the model for 10 test patients, were then compared with corresponding dose distributions calculated by a reliable treatment planning system. In particular, the dice similarity coefficients for different isodose volumes, dose difference and mean absolute errors (MAE) for all voxels inside the body, Dmean, D98%, D50%, D2%, V95% for planning target volume and organs at risk were calculated and were statistically analysed with the paired-samples t-test. ResultsThe average dose difference for all patients and voxels in body was 0.60 ± 2.81%. The MAE varied from 3.85 ± 6.65% to 8.06 ± 10.00%. The average MAE for test cases was 5.71 ± 1.19%. The average dice similarity coefficients for isodose volumes was 0.91 ± 0.03. The three-dimensional gamma passing rates with 3 mm/3% criteria varied from 78.99% to 97.58% for planning target volume and organs at risk, respectively. ConclusionsThe investigation showed that a deep-learning model can be applied to predict the three-dimensional dose distribution with optimal accuracy and precision for patients with left breast cancer. As further study, the model can be extended to predict dose distribution in other cancers.

A case of methotrexate-related lymphoproliferative disorder in the right lung with lung metastasis after left breast cancer surgery

A case of methotrexate-related lymphoproliferative disorder in the right lung with lung metastasis after left breast cancer surgery

Technical note: Clinical evaluation of a newly released surface-guided radiation therapy system on DIBH for left breast radiation therapy.

It has been shown that a significant reduction of mean heart dose and left anterior descending artery (LAD) dose can be achieved through the use of DIBH for left breast radiation therapy. Surface-guided DIBH has been widely adopted during the last decade, and there are mainly three commercially available SGRT systems. The reports of the performance of a newly released SGRT system for DIBH application are currently very limited. To evaluate the clinical performance of a newly released SGRT system on DIBH for left breast radiation therapy. Twenty-five left breast cancer patients treated with DIBH utilizing Varian's Identify system were included (total 493-fraction treatments). Four aspects of the clinical performance were evaluated: Identify offsets of free breathing post patient setup from tattoos, Identify offsets during DIBH, Identify agreement with radiographic ports during DIBH, and DIBH reference surface re-capture post patient shifts. The systematic and random errors of free breathing Identify offsets post patient setup were calculated for each patient, as well as for offsets during DIBH. Radiographic ports were taken when the patient's DIBH position was within the clinical tolerance of (±0.3cm,±30 ), and these were then compared with treatment field DRRs. If the ports showed that the patient alignment did not agree with the DRRs within 3mm, a patient shift was performed. A new reference surface was captured and verification ports were taken. The all-patient average systematic and random errors of Identify offsets for free breathing were within (0.4cm, 1.50 ) post tattoo setup. The maximum per-patient systematic and random errors were (1.1cm, 6.20 ) and (0.9cm, 20 ), and the maximum amplitude of Identify offsets were (2.59cm, 90 ). All 493-fraction DIBH treatments were delivered and successfully guided by the Identify SGRT system. The systematic and random errors of Identify offsets for DIBH were within (0.2cm, 2.30 ). Seven patients needed re-captured surface references due to surface variation or position shifts based on the ports. All patient DIBH verification ports guided by Identify were approved by attending physicians. This evaluation showed that the Identify system performed effectively for surface-guided patient setup and surface-guided DIBH imaging and treatment delivery. The feature of color-coded real-time patient surface matching feedback facilitated the evaluation of the patient alignment accuracy and the adjustment of the patient position to match the reference.

Is Occupational Arsenic Exposure a Possible Causative Agent of Breast Cancer for a Young Female Laboratory Technician? A Case-Study

A 28-year-old female laboratory technologist who was exposed to highly concentrated inorganic arsenic for 7 years, 25 hours a week, presented with left breast cancer. When most epidemiologic evidence reported by the IARC supported the relationship between arsenic exposure and cancers of lung, skin and bladder; literature had documented increased risk of breast cancer in specific populational subgroups due to the estrogen-like activity of arsenic. The causal assessment of occupational cancer is challenging due to the lack of relevant data on the worker’s biological monitoring and environmental exposure monitoring data, together with the insufficient genetic composition information like BRCA1 gene. Moreover, the poor work practice and hygiene had made the exposure through dermal contact and digestion possible. The interpretation of work causal relationship while distinct occupational cancer from those of non-occupational must consider individual susceptibility as low-level short-period exposure might increase the risk for certain worker. Therefore, a systematically collected medical surveillance data along with industry hygiene data is highly recommended in order to assist in the refinement of human dose-response relationship of specific work carcinogen

Beyond the heart in hypofractionated radiotherapy and in the transition from 3D to IMRT/VMAT.

The knowledge of the risks induced by radiation with hypofractionation regimens has only recently been estimated together with its implementation as a management standard. However, the dose to other risk organs with intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT) is not clear, that is why this is only a reference study of radiation doses to organs at risk in hypofractionation in our center. We completed a retrospective and observational analysis of 1398 patients treated with adjuvant hypofractionated radiotherapy from 2015 to 2018, using the clinical records and dose-volume histogram of patients treated with moderate hypofractionated adjuvant radiotherapy. To analyze the institutional experience on the dosimetry of the esophagus and liver as risk organs in the use of moderate adjuvant hypofractionated radiotherapy in breast cancer. The dosimetry of the esophagus was 3271 cGy DMax, 177 cGy DMed, 68 cGy D50%, 500 cGy DcMAX with 3D RT and 4124 cGy DMax, 1242 cGy DMed, 934.50 cGy D50%, 3213 cGy DcMAX with IMRT/VMAT and the dosimetry for the liver was for right breast cancer 466 cGy DMed, 102 cGy D50% and 8% V20, for left breast cancer 22 cGy DMed, 6.10 cGy D50% and 0.3% V20. The statistically significant differences in irradiation show the lack of consensus on the optimal restrictions in hypofractionation regimens to reduce clinical sequela; consequently, the variability in the specification of each radiation oncologist is observed; standardization in our center can lead to improvement in the quality of treatments.

Can we predict who will benefit from the deep inspiration breath hold (DIBH) technique for breast cancer irradiation?

The objective was to explore the clinical use of an "in-house" prototype developed to monitor respiratory motion to implement the deep inspiration breath hold technique (DIBH), compare dosimetric differences, and assess whether simple anatomic metrics measured on free breathing (FB) computed tomography scan (CT) can help in selecting patients that would benefit the most from the technique. A prospective study was conducted on patients with left breast cancer with an indication of adjuvant radiotherapy for breast only. Treatment simulation consisted of four series of CTs: the first during FB and three in DIBH to assess the reproducibility and stability of apnea. Contouring was based on the RTOG atlas, and planning was done in both FB and DIBH. Dosimetric and geometric parameters were assessed and compared between FB and DIBH. From June 2020 to December 2021, 30 patients with left breast cancer were recruited. Overall, the DIBH technique presented a mean dose reduction of 24% in the heart and 30% in the left anterior descendent coronary artery (LAD) (p < 0.05). The only geometric parameter correlated to a 30% dose reduction in the mean heart dose and LAD doses was the anterolateral distance from the heart to the chest wall of at least 1.5 cm measured on FB (p < 0.0001). The prototype enabled the use of the DIBH technique with dose reductions in the heart and LAD. The benefit of the DIBH technique can be predicted on FB CT by measuring the distance between the heart and chest wall at the treatment isocenter.

Investigating the Radiation Dose Received by the Heart and Its Electrocardiographic Changes after Three-dimensional Conformal Radiation Therapy in Patients with Left Breast Cancer

Background and Objective: Breast cancer is one of the most common cancers and the fifth leading cause of cancer deaths in Iran. The present study aimed to investigate the absorbed dose received by the heart and its relationship with cardiac complications in radiotherapy of patients with left breast cancer using a three-dimensional conformal radiotherapy technique. Materials and Methods: A total of 181 women with left breast cancer who received radiotherapy after surgery were included in the study. Dosimetric parameters were obtained using dose-volume histograms for the heart, whole lung, left lung, and clinical target volume. Electrocardiography tests were performed for all patients before and one year after the radiotherapy. Results: The mean doses of heart, left lung, whole lung, and clinical target volume were 6.3±3.1, 13.3±4.5, 6.9±3.7, and 47.3±6.4 Gray (Gy), respectively. A significant reduction in T-wave amplitude was observed in 57% of patients three months after radiotherapy. T-wave amplitude decreased from 3.03±0.92 mm to 1.56±0.83 mm. The reduction in the T-wave amplitude displayed a significant relationship with the mean dose of the heart (β = 2.653; P= 0.019). Conclusion: In women with left-sided breast cancer, cardiac complications are frequent, for which electrocardiographic tests can be used for cardiac evaluation after radiotherapy. Based on the obtained results, the most frequent side effect caused by radiotherapy in these patients was an abnormality in T-wave

Breast MRI in patients with implantable loop recorder: initial experience.

To investigate the feasibility of breast MRI exams and guided biopsies in patients with an implantable loop recorder (ILR) as well as the impact ILRs may have on image interpretation. This retrospective study examined breast MRIs of patients with ILR, from April 2008 to September 2022. Radiological reports and electronic medical records were reviewed for demographic characteristics, safety concerns, and imaging findings. MR images were analyzed and compared statistically for artifact quantification on the various pulse sequences. Overall, 40/82,778 (0.049%) MRIs during the study period included ILR. All MRIs were completed without early termination. No patient-related or device-related adverse events occurred. ILRs were most commonly located in the left lower-inner quadrant (64.6%). The main artifact was a signal intensity (SI) void in a dipole formation in the ILR bed with or without areas of peripheral high SI. Artifacts appeared greatest in the cranio-caudal axis (p < 0.001), followed by the anterior-posterior axis (p < 0.001), and then the right-left axis. High peripheral rim-like SI artifacts appeared on the post-contrast and subtracted T1-weighted images, mimicking suspicious enhancement. Artifacts were most prominent on diffusion-weighted (p < 0.001), followed by T2-weighted and T1-weighted images. In eight patients, suspicious findings were found on MRI, resulting in four additional malignant lesions. Of six patients with left breast cancer, the tumor was completely visible in five cases and partially obscured in one. Breast MRI is feasible and safe among patients with ILR and may provide a significant diagnostic value, albeit with localized, characteristic artifacts. Indicated breast MRI exams and guided biopsies can be safely performed in patients with implantable loop recorder. Nevertheless, radiologists should be aware of associated limitations including limited assessment of the inner left breast and pseudo-enhancement artifacts. • Breast MRI in patients with an implantable loop recorder is an infrequent, feasible, and safe procedure. • Despite limited breast visualization of the implantable loop recorder bed and characteristic artifacts, MRI depicted additional lesions in 8/40 (20%) of cases, half of which were malignant. • Breast MRI in patients with an implantable loop recorder should be performed when indicated, taking into consideration typical associated artifacts.