Intensity modulated radiation therapy for breast cancer: current perspectives

Ultra-Hypofractionated Whole Breast Radiotherapy with Automated Hybrid-VMAT Technique: A Pilot Study on Safety, Skin Toxicity and Aesthetic Outcomes

Purpose

The most prevalent treatment-related side effect related to adjuvant radiotherapy (RT) for breast cancer is acute skin toxicity in the irradiated area. The purpose of this single-institution pilot study is to provide preliminary clinical results on the feasibility and safety of a breast ultra-hypofractionated radiation treatment delivered using an automated hybrid-VMAT technique. Skin damage was assessed both with clinical examination and objectively using a Cutometer equipment.

Patients and Methods

Patients received 26 Gy to the whole breast and 30 Gy to the tumoral bed in 5 fractions using an automated hybrid-VMAT approach with the option for the breath hold technique if necessary. Acute and late toxicities were clinically evaluated at baseline, 1- and 6-months after treatment using the CTC-AE v.5.0 scale. An instrumental evaluation of the skin elasticity was performed using a Cutometer® Dual MP580. Two parameters per patient, R0 (the total skin firmness) and Q1 (the elastic recovery), were registered at the different timelines.

Results

From June 2022 to January 2024, 30 patients, stage T1-T2, N0 were enrolled in the study. Four out of 30 (13.3%) patients reported G2 acute skin toxicities. At 6 months, G2 late toxicity was registered in 3 patients (10%). A total of 2160 measures of R0 and Q1 were recorded. At 1 month after treatment, no correlation was found between measured values of R0 and Q1 and clinical evaluation. At 6 months after treatment, clinical late toxicity ≥1 was strongly associated with decreased R0 and Q1 values ≥24% (p = 0.003) and ≥18% (p = 0.022), respectively.

Conclusion

Ultra-hypofractionated whole-breast radiotherapy, when supported by advanced treatment techniques, is both feasible and safe. No severe adverse effects were observed at any of the different timeframes. Acute and late skin toxicities were shown to be lower in contrast to data presented in the literature.

An IMRT planning technique for treating whole breast or chest wall with regional lymph nodes on Halcyon and Ethos

PURPOSE/OBJECTIVE

Field size limitations on Halcyon and Ethos treatment machines largely preclude use of the conventional monoisocentric three-field technique for breast/chest wall and regional lymph nodes. We present an alternative, IMRT-based planning approach that facilitates treatment on Halcyon and Ethos while preserving plan quality.

MATERIALS/METHODS

Eight breast and regional node cases (four left-sided, four right-sided) were planned for an Ethos machine using a 15-17 field IMRT technique. Institutional plan quality metrics for CTV and PTV coverage and OAR sparing were assessed. Five plans (four right-sided, one left-sided) were also planned using a hybrid 3D multisocenter technique. CTV coverage and OAR sparing were compared to the IMRT plans. Eclipse scripting tools were developed to aid in beam placement and plan evaluation through a set of dosimetric scorecards, and both are shared publicly.

RESULTS

On average, the IMRT plans achieved breast CTV and PTV coverage at 50 Gy of 97.9% and 95.7%, respectively. Supraclavicular CTV and PTV coverages at 45 Gy were 100% and 95.5%. Axillary lymph node CTV and PTV coverages at 45 Gy were 100% and 97.1%, and IMN CTV coverage at 45 Gy was 99.2%. Mean ipsilateral lung V20 Gy was 19.3%, and average mean heart dose was 1.6 Gy for right-sided cases and 3.0 Gy for left-sided. In comparison to the hybrid 3D plans, IMRT plans achieved higher breast and supraclavicular CTV coverage (99.9% vs. 98.6% and 99.9% vs. 93.4%), higher IMN coverage (99.6% vs. 78.2%), and lower ipsilateral lung V20 Gy (19.6% vs. 28.2%).

CONCLUSION

Institutional plan quality benchmarks were achieved for all eight cases using the IMRT-based planning approach. The IMRT-based planning approach offered superior conformity and OAR sparing than a competing hybrid 3D approach.

Personalized Radiation Therapy for Breast Cancer

Breast cancer is diagnosed in nearly 3 million people worldwide. Radiation therapy is an integral component of disease management for patients with breast cancer, and is used after breast-conserving surgery or a mastectomy to reduce the risk of a local recurrence. The following review describes the methods used to personalize radiation therapy by optimizing patient selection, using advanced treatment techniques to lessen the radiation dose to normal organs, and using hypofractionation in order to shorten the duration of radiation treatment.

Non-invasive physical plasma for preventing radiation dermatitis in breast cancer: Results from an intrapatient-randomised double-blind placebo-controlled trial

Background and Purpose

To investigate the effect of topical non-invasive physical plasma (NIPP), a volatile mix generated out of ambient air, on prevention of acute radiation dermatitis (RD) during and after whole-breast irradiation (WBI).

Materials and Methods

Lateral and medial breast halves were randomised within each patient to receive either 120 s of NIPP or sham treatment daily during WBI. Standard skin care with urea lotion was applied to the whole breast. Blinded acute skin toxicity was assessed weekly for each breast half separately and included clinician- (CTCAE) and patient-reported (modified RISRAS), and objective (spectrophotometry) assessments. As an additional external control, a comparable standard of care (SoC) patient collective from a previous prospective trial was used.

Results

Sixty-four patients were included. There were no significant differences between breast halves. Post-hoc comparison with a similar SoC control collective revealed OR = 0.28 (95% CI 0.11-0.76; p = 0.014) for grade ≥ 2 RD upon WBI completion, along with less hyperpigmentation (p < 0.001), oedema (p = 0.020), dry (p < 0.001) and moist desquamation (p = 0.017), pain, itching, and burning (p < 0.001 for each). Tolerability of NIPP was excellent and side effects were not observed.

Conclusion

Even though there were no differences between intrapatient-randomised breast halves, the overall incidence and severity of acute radiation-induced skin toxicity were considerably lower when compared to a prospectively collected SoC cohort. Our data suggest the potential benefit of NIPP in RD prevention. A randomised trial with a physical control group is warranted to confirm these promising results (DRKS00026225).

Bioinspired thiazolo-[2,3-b] quinazolin-6-one derivatives as potent anti-cancer agents targeting EGFR: their biological evaluations and in silico assessment

Cancer is a challenging and second most deadly disease. The epidermal growth factor receptors (EGFRs) dimerize upon ligand bindings to the extracellular domain that intiates the downstream signaling cascades and activates intracellular kinase domain. Thus, activation of autophosphrylation through kinase domain results in metastasis, cell proliferation, and angiogenesis. In this study, we unravel the binding mechanism of newly synthesized thiazolo-[2,3-b] quinazolin-6-one and evaluate their anti-cancer activity against ovary and prostate carcinoma cell lines (OVCAR-3 and PC-3). Synthesized molecules exhibited promising anti-cancer activity against OVCAR-3 and PC-3 carcinoma cell lines with inhibitory concentrations ranging from 13.4 ± 0.43 to 23.6 ± 1.22 μM and 7.5 ± 0.62 to 67.5 ± 1.24 μM, respectively. These compounds induced apoptosis and resulted in cell cycle arrest at G1 and G2/M transition phases. Next, the nude mice models were taken to investigate the toxicity of the 4bi compound, and in vivo investigations revealed no effects upon examined organs (liver and kidney) treated at different concentrations. Moreover, the combined in silico approaches, molecular docking, molecular dynamics simulations, and MM/PBSA methods were performed to assess the binding affinity and stability of bioinspired synthesized congeners with the epidermal growth factor receptor tyrosine kinase (EGFR-TK). The free binding energy (ΔG_bind) of the 4bi molecule was found comparable to Erlotinib drug. The test molecule could be competent for further usage to determine its efficicacy in cancer therapeutics.

Early Outcome, Cosmetic Result and Tolerability of an IOERT-Boost Prior to Adjuvant Whole-Breast Irradiation

Background/Aims: Due to its favorable dose distribution and targeting of the region at highest risk of recurrence due to direct visualization of tumor bed, intraoperative electron radiation therapy (IOERT) is used as part of a breast-conserving treatment approach. The aim of this study was to analyze tumor control and survival, as well as the toxicity profile, and cosmetic outcomes in patients irradiated with an IOERT boost for breast cancer. Materials and Methods: 139 Patients treated at our institution between January 2010 and January 2015 with a single boost dose of 10 Gy to the tumor bed during breast-conserving surgery followed by whole-breast irradiation were retrospectively analyzed. Results: 139 patients were included in this analysis. The median age was 54 years (range 28−83 years). The preferred surgical strategy was segmental resection with sentinel lymphonodectomy (66.5%) or axillary dissection (23.1%). Regarding adjuvant radiotherapy, the vast majority received 5 × 1.8 Gy to 50.4 Gy. At a median follow-up of 33.6 months, recurrence-free and overall survival were 95.5% and 94.9%, respectively. No patient developed an in-field recurrence. Seven patients (5.0%) died during the follow-up period, including two patients due to disease recurrence (non-in-field). High-grade (CTCAE > 2) perioperative adverse events attributable to IOERT included wound healing disorder (N = 1) and hematoma (N = 1). High-grade late adverse events (LENT-SOMA grade III) were reported only in one patient with fat necrosis. Low-grade late adverse events (LENT-SOMA grade I-II) included pain (18.0%), edema (10.5%), fibrosis (21%), telangiectasia (4.5%) and pigmentation change (23.0%). The mean breast retraction assessment score was 1.66 (0−6). Both patients and specialists rated the cosmetic result “excellent/good” in 84.8% and 87.9%, respectively. Conclusion: Our study reports favorable data on the cosmetic outcome as well as the acute and early long-term tolerability for patients treated with an IOERT boost. Our oncologic control rates are comparable to the previous literature. However, prospective investigations on the role of IOERT in comparison to other boost procedures would be desirable.

Automated hybrid volumetric modulated arc therapy (HVMAT) for whole-breast irradiation with simultaneous integrated boost to lumpectomy area : A treatment planning study

PURPOSE

To develop an automated treatment planning approach for whole breast irradiation with simultaneous integrated boost using an automated hybrid VMAT class solution (HVMAT).

MATERIALS AND METHODS

Twenty-five consecutive patients with left breast cancer received 50 Gy (2 Gy/fraction) to the whole breast and an additional simultaneous 10 Gy (2.4 Gy/fraction) to the tumor cavity. Ipsilateral lung, heart, and contralateral breast were contoured as main organs-at-risk. HVMAT plans were inversely optimized by combining two open fields with a VMAT semi-arc beam. Open fields were setup to include the whole breast with a 2 cm flash region and to carry 80% of beams weight. HVMAT plans were compared with three tangential techniques: conventional wedged-field tangential plans (SWF), field-in-field forward planned tangential plans (FiF), and hybrid-IMRT plans (HMRT). Dosimetric differences among the plans were evaluated using Kruskal-Wallis one-way analysis of variance. Dose accuracy was validated using the PTW Octavius-4D phantom together with the 1500 2D-array.

RESULTS

No significant differences were found among the four techniques for both targets coverage. HVMAT plans showed consistently better PTVs dose contrast, conformity, and homogeneity (p < 0.001 for all metrics) and statistically significant reduction of high-dose breast irradiation. V55 and V60 decreased by 30.4, 26.1, and 20.8% (p < 0.05) and 12.3, 9.9, and 6.0% (p < 0.05) for SWF, FIF, and HMRT, respectively. Pretreatment dose verification reported a gamma pass-rate greater than the acceptance threshold of 95% for all HVMAT plans. In addition, HVMAT reduced the time for full planning optimization to about 20 min.

CONCLUSIONS

HVMAT plans resulted in superior target dose conformity and homogeneity compared to other tangential techniques. Due to fast planning time HVMAT can be applied for all patients, minimizing the impact on human or departmental resources.

Dosimetric Comparison of Four Different Radiotherapy Planning Techniques for Adjuvant Radiotherapy of Left-Sided Breast, Axilla, and Supraclavicular Fossa

Purpose/Aim:

Forward planned intensity-modulated radiotherapy (forward IMRT) with breath-hold (BH) technique is considered optimal by most practitioners for treating left-sided breast cancer. Regional nodal irradiation including axilla and supraclavicular fossa (SCF) increases can increase dose-to-organs at risk (OAR) especially lung. This study was done to assess the potential of inverse planned IMRT (inverse IMRT) to achieve significant reduction in dose to OAR.

Materials and Methods:

Ten patients with left-sided breast cancer treated with Active Breath Co-ordinator BH technique were included in the study. Forward IMRT plans were generated in both BH and free breathing (FB) scans. Inverse IMRT plans were generated in FB scan using Tomotherapy-Direct and Tomotherapy-Helical techniques. Contouring was done as per the ESTRO consensus contouring guidelines. The dose prescribed was 40 Gy in 15 fractions. Statistical significance was tested using one-way ANOVA for parametric data and Kruskall–Wallis test for nonparametric data. Multiple comparison tests were done by using Bonferroni test. P <0.05 was considered to denote statistical significance.

Results:

Inverse IMRT plans achieved superior homogeneity index compared to forward IMRT with BH. Tomotherapy-Direct reduced dose to ipsilateral lung, compared to the forward IMRT with BH while achieving similar doses to other OAR. Tomotherapy-Helical plans achieved significantly better conformity index and reduced maximum dose to left anterior descending artery compared to forward IMRT plans, but low dose to other OAR was significantly worse.

Conclusion:

For left-sided breast, axilla, and SCF radiotherapy, inverse IMRT with Tomotherapy-Direct plan achieved better homogeneity index and reduced dose to ipsilateral lung compared to forward IMRT with BH.

Is prone free breathing better than supine deep inspiration breath-hold for left whole-breast radiotherapy? A dosimetric analysis

PURPOSE

The advantage of prone setup compared with supine for left-breast radiotherapy is controversial. We evaluate the dosimetric gain of prone setup and aim to identify predictors of the gain.

METHODS

Left-sided breast cancer patients who had dual computed tomography (CT) planning in prone free breathing (FB) and supine deep inspiration breath-hold (DiBH) were retrospectively identified. Radiation doses to heart, lungs, breasts, and tumor bed were evaluated using the recently developed mean absolute dose deviation (MADD). MADD measures how widely the dose delivered to a structure deviates from a reference dose specified for the structure. A penalty score was computed for every treatment plan as a weighted sum of the MADDs normalized to the breast prescribed dose. Changes in penalty scores when switching from supine to prone were assessed by paired t-tests and by the number of patients with a reduction of the penalty score (i.e., gain). Robust linear regression and fractional polynomials were used to correlate patients' characteristics and their respective penalty scores.

RESULTS

Among 116 patients identified with dual CT planning, the prone setup, compared with supine, was associated with a dosimetric gain in 72 (62.1%, 95% CI: 52.6-70.9%). The most significant predictors of a gain with the prone setup were the breast depth prone/supine ratio (>1.6), breast depth difference (>31 mm), prone breast depth (>77 mm), and breast volume (>282 mL).

CONCLUSION

Prone compared with supine DiBH was associated with a dosimetric gain in 62.1% of our left-sided breast cancer patients. High pendulousness and moderately large breast predicted for the gain.

Intensity-Modulated Radiotherapy with Concomitant Boost After Breast Conserving Surgery: A Phase I-II Trial

Purpose

A concomitant boost (CB) in patients treated with postoperative radiotherapy after conservative surgery of invasive breast cancer (BC) has been suggested for treatment time reduction and therapy intensification. The aim of this analysis was to assess long-term tolerability of a CB in patients treated with postoperative intensity Modulated Accelerated RAdiotherapy (MARA).

Patients and Methods

In this phase I–II trial, 321 patients with intermediate-high risk BC (pT1-4 with at least one of the following characteristics: pre or perimenopausal status, pN2-3, positive or close margins) were enrolled. Patients were treated with forward-planned intensity modulated radiotherapy (IMRT) and CB. A total dose of 50 Gy (2 Gy/fraction) and 60 Gy (2.4 Gy/fraction) was prescribed to the whole breast and the tumor bed, respectively. The potential impact of hypertension, diabetes, smoking habit, alcohol consumption, chemotherapy, and hormone therapy on both skin and subcutaneous late toxicity-free survival (LTFS) was evaluated. Survival curves were calculated using the Kaplan–Meier method.

Results

Median follow-up was 52 months (range: 3–115). Regional node irradiation, adjuvant chemotherapy and hormonal therapy were prescribed to 29.3%, 65.4% and 81.0% of patients, respectively. Five-year G2 and G3 skin LTFS were 95.6% and 100.0%, respectively. Five-year G2 and G3 subcutaneous LTFS were 80.0% and 98.6%, respectively. Only diabetes showed a significant correlation with worse G3 subcutaneous LTFS (p: 0.024). Five-year loco-regional control, metastasis-free survival, disease-free survival, and overall survival were 98.0%, 91.8%, 89.7% and 96.3%, respectively.

Conclusion

IMRT combined with CB was associated with a low risk of > G2 late toxicities (0.0% and 1.4% for skin and subcutaneous tissue, respectively). The cumulative actuarial incidence of local recurrences was 2.0% despite the exclusion of low-risk patients. Our results suggest that CB is safe and effective in patients with intermediate-high risk BC.

Trial Registration

ClinicalTrials.gov: NCT03471741.

Dermatologic toxicities associated with radiation therapy in women with breast cancer

Breast-conserving surgery with adjuvant radiation therapy has become the standard of care for women with early stage breast cancer, and as a result, a large number of patients are affected by the cutaneous sequelae of radiation therapy. These dermatologic toxicities may present during treatment or years later and can significantly impact patients’ quality of life. In this review, we discuss the clinical presentation, prevention, and management of radiation-induced cutaneous toxicities in women with breast cancer, including radiation dermatitis, radiation recall, radiation-induced morphea, radiation-induced fibrosis, and cutaneous malignancies in irradiated skin.

Two-Level Factorial Pre-TomoBreast Pilot Study of Tomotherapy and Conventional Radiotherapy in Breast Cancer: Post Hoc Utility of a Mean Absolute Dose Deviation Penalty Score

Background:

A 2-level factorial pilot study was conducted in 2007 just before starting a randomized clinical trial comparing tomotherapy and conventional radiotherapy (CR) to reduce cardiac and pulmonary adverse effects in breast cancer, considering tumor laterality (left/right), target volume (with/without nodal irradiation), surgery (tumorectomy/mastectomy), and patient position (prone/supine). The study was revisited using a penalty score based on the recently developed mean absolute dose deviation (MADD).

Methods:

Eight patients with a unique combination of laterality, nodal coverage, and surgery underwent dual tomotherapy and CR treatment planning in both prone and supine positions, providing 32 distinct combinations. The penalty score was applied using the weighted sum of the MADDs. The Lenth method for unreplicated 2-level factorial design was used in the analysis.

Results:

The Lenth analysis identified nodal irradiation as the active main effect penalizing the dosimetry by 1.14 Gy (P = 0.001). Other significant effects were left laterality (0.94 Gy), mastectomy (0.61 Gy), and interactions between left mastectomy (0.89 Gy) and prone mastectomy (0.71 Gy), with P-values between 0.005 and 0.05. Tomotherapy provided a small reduction in penalty (reduction of 0.54 Gy) through interaction with nodal irradiation (P = 0.080). Some effects approached significance with P-values > 0.05 and ≤ 0.10 for interactions of prone × mastectomy × left (0.60 Gy), nodal irradiation × mastectomy (0.59 Gy), and prone × left (0.55 Gy) and the main effect prone (0.52 Gy).

Conclusions:

The historical dosimetric analysis previously revealed the feasibility of tomotherapy, but a conclusion could not be made. The MADD-based score is promising, and a new analysis highlights the impact of factors and hierarchy of priorities that need to be addressed if major gains are to be attained.

CPAP (Continuous Positive Airway Pressure) is an effective and stable solution for heart sparing radiotherapy of left sided breast cancer

PURPOSE

Limiting the heart dose in left sided breast cancer radiotherapy is critical. We sought to study the effect of using CPAP (continuous positive airway pressure) as an aid in reducing heart dose in breast cancer radiotherapy.

METHODS

Patients with left sided breast cancer receiving adjuvant radiotherapy were enrolled on a prospective IRB (institutional review board) approved clinical trial utilizing CPAP during radiotherapy. Each patient was simulated and planned with and without CPAP and the best dosimetric results determined the patient's treatment. Data on the differences in lung and heart volume and position as well as boost cavity position with and without CPAP were analyzed.

RESULTS

Twenty-four women from 10/16 to 10/18 were enrolled. Seven patients were not treated on study; only two of these were due to treatment issues. Median age was 54 years. 70% had breast only radiation and 30% were treated to breast\CW (chest wall) and regional nodes. The median lung volume with CPAP was 60% larger than without CPAP. (1637 vs. 996 cc) p < 0.001. The median heart volume decreased 12% with CPAP. (338 vs. 382 cc) In regards to the DVH, CPAP decreased mean heart dose from 3.02 to 1.6Gy (p = .0075) and V20 of the lungs from 17.1 to 13.8 with CPAP but this was not significant.

CONCLUSION

CPAP assisted radiotherapy was tolerable and produced superior treatment plans in left sided breast cancer. This method is worthy of further investigation as a method to normal tissue sparing treatment of left sided breast cancer patients.

Intensity-modulated radiotherapy and hypofractionated volumetric modulated arc therapy for elderly patients with breast cancer: comparison of acute and late toxicities

PURPOSE

To evaluate the differences between conventional fractionated intensity-modulated radiotherapy (IMRT) and hypofractionated (HypoRT) volumetric modulated arc therapy (VMAT) in elderly women affected by early-stage breast cancer (BC) in terms of RT-related acute/late side effect.

MATERIALS AND METHODS

Between October 2011 and July 2015, 80 consecutive elderly BC patients were treated with IMRT for 5 weeks (40 patients) or HypoRT-VMAT for 3 weeks (40 patients). Inclusion criteria were: age ≥ 70 years, early BC (pT1-2 pN0-1), no prior neoadjuvant chemotherapy and non-metastatic disease. For patients receiving IMRT or HypoRT-VMAT, a total dose of 50 Gy (25 fractions) or 40.5 Gy (15 fractions) was prescribed to the whole ipsilateral breast, respectively. All patients received a simultaneously integrated boost up to a total dose of 60 Gy for IMRT and 48 Gy for HypoRT-VMAT. Acute and late side effects were evaluated using the RTOG/EORTC radiation morbidity scoring system.

RESULTS

With a median follow-up of 45 months, acute skin toxicity was overall very low, with grade 1 in 25 cases (62.5%) of the IMRT group and 21 cases (52.5%) of the HypoRT-VMAT group, while grade 2 toxicity was reported in 10 IMRT patients (25%) and 1 HypoRT-VMAT patient (2.5%) (p = 0.001). Regarding late adverse events, only grade 1 skin toxicity was recorded.

CONCLUSION

The present study showed that whole breast IMRT and HypoRT-VMAT are feasible and well tolerated in early-stage BC elderly patients and that HypoRT-VMAT is affected by lower risk of acute and late RT-related side effects.

Hypofractionated radiotherapy after conservative surgery may increase low-intermediate grade late fibrosis in breast cancer patients

Aim

To compare late toxicity after postoperative hypofractionated radiotherapy (RT) and standard fractionated RT in patients with early-stage breast carcinoma.

Methods

This retrospective study included 447 patients (Modulated Accelerated Radiotherapy [MARA-1]: 317 patients, and control group [CG]: 130 patients). In the CG, the whole breast received 50.4 Gy in 28 fractions (fx) using 3D-radiotherapy, plus a sequential electron boost (10 Gy in 4 fx) to tumor bed. In MARA-1 group, a forward-planned intensity-modulated radiotherapy technique with 40 Gy in 16 fx with a concomitant boost of 4 Gy to breast was used. The primary endpoint was to evaluate late toxicity, and secondary endpoints were acute toxicity, local control, and survival. ClinicalTrials.gov: NCT03461224.

Results

Median follow-up was 52 months (range: 3–115 months). Late skin and subcutaneous toxicity were acceptable: 5-year actuarial cumulative incidence of Grade (G) 3 late skin toxicity was 1.5% in CG and 0.0% in MARA-1. Five-year actuarial cumulative incidence of G3 late subcutaneous toxicity was 0.8% in CG and 0.3% in MARA-1. On multivariate analysis, tobacco smoking and planning target volume were associated with an increased risk of late G1 skin toxicity (HR: 2.15, 95% CI: 1.38–3.34 and HR: 1.12, 95% CI: 1.07–1.18, respectively), whereas patients with a larger planning target volume also showed an increased risk of G1 and G2 late subcutaneous toxicity (HR: 1.14, CI 95%: 1.08–1.20 and HR: 1.14, 95% CI: 1.01–1.28, respectively). MARA-1 patients also showed an increased risk of late G1 and G2 subcutaneous toxicity (HR: 2.35, 95% CI: 1.61–3.41 and HR: 3.07, 95% CI: 1.11–8.53, respectively) compared to CG.

Conclusion

In this retrospective analysis, postoperative accelerated-hypofractionated RT for early-stage-breast carcinoma was associated with higher incidence of subcutaneous side effects. However, this increase was limited to G1–G2 toxicity. In the future, development of predictive models could help in tailoring dose and fractionation based on the risk of toxicity.

The use of helical tomotherapy in the treatment of early stage breast cancer: indications, tolerance, efficacy-a single center experience

PURPOSE

to evaluate our experience in terms of local control, survival, adverse effects in patients treated by adjuvant helical tomotherapy (HT) for breast cancer (BC).

RESULTS

We studied 179 consecutive patients with 194 treated breasts with adjuvant HT. Median follow-up was 38.1 months. Median age was 53 years. Chemotherapy was administered to 83% of patients. All 133 hormone receptor positive tumours received hormonal therapy. As concurrent treatment, apart from trastuzumab monotherapy, 6 patients received systemic therapy concomitant to RT. The HT was generally well tolerated with mostly grade 1 and 2 skin reactions and esophagitis. Only 3% grade III early skin reactions. At last follow-up, there were 2 local recurrences, 1 regional lymph node (LN) recurrence and 6 with metastatic progression. The 5-year progression-free survival was 90.5% (95% CI 84.2-97.3).

MATERIALS AND METHODS

A retrospective study of all patients treated by HT between 2009 and 2015 was done. Patients excluded were those with: breast implants, advanced or metastatic BC, recurrent disease. All patients received breast+/-boost or chest wall irradiation and most received with LN irradiation. Dose constraints for organs at risk were defined using optimization scale developed in our Department. Evaluation of early and late toxicity was done using Common Terminology Adverse Criteria Events v.4.0.

CONCLUSIONS

HT can be used for a well selected group of breast cancer as bilateral tumours, complex anatomy and target volumes where the conventional radiation therapy techniques cannot ensure an optimal dose distribution. Longer follow-up is necessary to confirm and validate these results.