Early Results of the French Multicenter, Randomized SHARE Trial Comparing Whole Breast Irradiation vs. Accelerated Partial Breast Irradiation in Postmenopausal Women with Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

The aim is to report toxicity and cosmetic outcomes at 3 and up to 9 years of follow-up of post-menopausal patients randomized to receive either standard whole breast irradiation (WBI), including hypofractionated options, versus accelerated partial breast irradiation (APBI).

MATERIALS/METHODS

From December 2010 to July 2015, 1006 patients were enrolled in 34 French centers. Among the whole population, 28 patients who did not meet the final selection criteria or withdrew consent were excluded leading to a modified intention to treat analysis dataset of 978 patients (WBI: n = 488; APBI: n = 490). Median age (65y) and tumor stage pT1 (99%) rates were similar in both arms. Patients had conservative surgery with clip placement in the tumor bed. Clear margins (> 2mm) were observed in 99% of the patients. In both arms, 96-97% of the patients had negative sentinel lymph node biopsy. The median time interval between surgery and radiotherapy was 57d in WBI vs 62d in APBI. WBI schedules consisted of 50 Gy in 25 fr+16 Gy (n = 212) or 40 Gy in 15 fr (n = 156) or 42.5 Gy in 16 fr (n = 120). APBI arm consisted of 38.5 Gy or 40 Gy in 10 fr, 2 fr/day. Overall, 94 patients from the APBI arm finally received standard WBI. For statistical considerations, SHARE trial, sponsored by UNICANCER (NCT01247233) is a non-inferiority randomized controlled trial comparing APBI versus WBI in terms of local control as primary objective. Secondary endpoints were severe toxicity (NCI-CTCAE v4 grade ≥ 2), and cosmetic results. For both outcomes, we estimated the cumulative incidences (CI) using Kalbfleish and Prentice method, considering disease relapse, secondary cancer or death as competing events. Treatment effect (APBI vs WBI) was estimated by cause-specific Hazard Ratios (cs-HR) from Cox models.

RESULTS

Median follow-up was 5.8y (range, 0.13-9.5). The number of deaths was 27, and the number of local relapses was 8. Among the 978 patients, 582 and 396 had finally WBI and APBI, respectively. The rates of post-operative hematoma, edema and infection were low: 8-9%, 2%, 3-2%, respectively. When considering any type of severe toxicity, we observed a significant reduction rate in APBI compared to WBI: cs-HR = 0.73 (95% confidence interval: 0.61-0.88); p = 0.001, and 3-year CI of severe toxicity at 45% in WBI vs 36% in APBI arm. The difference was also in favor of APBI when considering breast skin toxicity alone: cs-HR = 0.55 (0.44-0.70), p<0.001 and 3-year CI at 36% in WBI vs 21% in APBI arm. Conversely, for breast other toxicities, WBI was found less toxic than APBI with a 3-year CI of 8% vs 15%, respectively. When considering cosmetic results, we observed no significant difference between the two arms in both evaluations by physicians and patients.

CONCLUSION

Historically SHARE is the first APBI trial that included hypofractionated schedules in the standard arm. We report increased risk of severe toxicity and skin breast toxicity in standard arm as compared with APBI arm without any difference in terms of cosmetic results. Longer follow-up is needed.

Economic evaluation and budget-impact of accelerated partial breast irradiation (APBI) versus standard or hypofractionated whole breast irradiation (WBI) in postmenopausal women with early-stage breast cancer. Results from the French SHARE randomized trial

PURPOSE

This economic evaluation reports the incremental cost-utility ratio and national budget impact in France of accelerated partial breast irradiation (APBI) vs standard or hypofractionated whole breast irradiation (WBI) in breast cancer patients at low risk of local recurrence.

MATERIALS AND METHODS

We compared 490 women randomized to the APBI (ten fractions delivered twice daily over one week) with 488 women in the WBI arm (one fraction per day delivered five days per week over three or six weeks). We took the perspective of the French national health insurance with a three-year time horizon. The outcome was quality-adjusted life years (QALYs). The incremental cost-effectiveness ratio was estimated and uncertainty was explored by probabilistic bootstrapping. Transportation and sick leave costs were added in a sensitivity analysis and a national budget impact analysis based on the incidence of breast cancer estimates in France performed.

RESULTS

At three years, the average cost per patient was €2,549 (±1,954) in the APBI arm and €4,468 (±1,586) in the WBI arm (p-value < 0.001), radiotherapy was the main driver of the difference between the two arms. No significant difference was found in QALYs. For an average of 60,000 new cases of breast cancer diagnosed annually in France, 28,000 would be eligible for treatment with APBI. A 100% uptake of APBI would result in a yearly30 million€ cost saving.

CONCLUSION

APBI for the treatment of postmenopausal women with early-stage breast cancer is cost saving, with no difference in outcome measured by QALYs.

Radiation-induced lung injury after breast cancer treatment: incidence in the CANTO-RT cohort and associated clinical and dosimetric risk factors

Purpose

Radiation-induced lung injury (RILI) is strongly associated with various clinical conditions and dosimetric parameters. Former studies have led to reducing radiotherapy (RT) doses to the lung and have favored the discontinuation of tamoxifen during RT. However, the monocentric design and variability of dosimetric parameters chosen have limited further improvement. The aim of our study was to assess the incidence of RILI in current practice and to determine clinical and dosimetric risk factors associated with RILI occurrence.

Material and methods

Data from 3 out of the 10 top recruiting centers in CANTO-RT, a subset of the CANTO prospective longitudinal cohort (NCT01993498), were retrospectively analyzed for RILI occurrence. This cohort, which recruited invasive cT0-3 cN0-3 M0 breast cancer patients from 2012 to 2018, prospectively recorded the occurrence of adverse events by questionnaires and medical visits at the end of, and up to 60 months after treatment. RILI adverse events were defined in all patients by the association of clinical symptoms and compatible medical imaging.

Results

RILI was found in 38/1565 (2.4%) patients. Grade II RILI represented 15/38 events (39%) and grade III or IV 2/38 events (6%). There were no grade V events. The most frequently used technique for treatment was 3D conformational RT (96%). In univariable analyses, we confirmed the association of RILI occurrence with pulmonary medical history, absence of cardiovascular disease medical history, high pT and pN, chemotherapy use, nodal RT. All dosimetric parameters were highly correlated and had close predictive value. In the multivariable analysis adjusted for chemotherapy use and nodal involvement, pulmonary medical history (OR=3.05, p<0.01) and high V30 Gy (OR=1.06, p=0.04) remained statistically significant risk factors for RILI occurrence. V30 Gy >15% was significantly associated with RILI occurrence in a multivariable analysis (OR=3.07, p=0.03).

Conclusion

Our study confirms the pulmonary safety of breast 3D RT in CANTO-RT. Further analyses with modern radiation therapy techniques such as IMRT are needed. Our results argue in favor of a dose constraint to the ipsilateral lung using V30 Gy not exceeding 15%, especially in patients presenting pulmonary medical history. Pulmonary disease records should be taken into account for RT planning.

Abstract PD3-05: Early results of the French multicenter, randomized SHARE trial comparing whole breast irradiation versus accelerated partial breast irradiation in postmenopausal women with early-stage breast cancer

Purpose: The aim of current analyses is to report toxicity and cosmetic outcomes at 3 and up to 9 years of follow-up of post-menopausal patients randomized to receive either standard external beam whole breast radiotherapy (WBI), including hypofractionated options, versus accelerated partial breast irradiation (APBI). Methods and materials: From December 2010 to July 2015, 1006 patients were enrolled in 34 French centers (503 in each arm). Among the whole population, 28 patients who did not meet the final selection criteria or withdrew consent were excluded leading to a modified intention to treat analysis dataset of 978 patients (WBI: n=488; APBI: n=490). Median age (65y) and tumor stage pT1 (99%) rates were similar in both arms. Patients had conservative surgery with clip placement in the tumor bed. Clear margins (&gt; 2mm) were observed in 99% of the patients. In both arms, 96-97% of the patients had negative sentinel lymph node biopsy (SLNB; median number: 4 in WBI arm and 5 in APBI), luminal BC. Ductal histology was observed 82%. Only 2% and 1% of patients had grade III and pN(i+) disease. The median time interval between surgery and radiotherapy was 57d in WBI vs 62d in APBI. WBI schedules consisted of: 50Gy in 25fr + 16Gy boost (n=212) or 40Gy in 15fr (n=156) or 42.5Gy in 16fr (n=120), while APBI arm consisted of 38.5Gy or 40Gy in 10fr. Overall, 94 patients from the APBI arm finally received standard WBI. For statistical considerations, SHARE trial, sponsored by UNICANCER (NCT01247233) is a non-inferiority randomized controlled trial comparing APBI versus WBI in terms of local control as primary objective. Secondary endpoints were severe toxicity (NCI-CTCAE v4 grade ≥ 2), and cosmetic results, evaluated by doctors and by patients, over the entire follow-up. For both outcomes, we estimated the cumulative incidences (CI) using Kalbfleish and Prentice method, considering disease relapse, secondary cancer or death as competing events. Treatment effect (APBI vs WBI) was estimated by cause-specific Hazard Ratios (cs-HR) from Cox models adjusted on stratification factors. Results: Median follow-up was 5.8y (range, 0.13-9.5). The number of deaths was 27, and the number of local relapses was 8. Among the 978 patients, 582 and 396 had finally WBI and APBI, respectively. The rates of post-operative hematoma, edema and infection were low: 8-9%, 2%, 3-2%, respectively. When considering any type of severe toxicity, we observed a significant reduction rate in APBI compared to WBI: cs-HR=0.73 (95% confidence interval: 0.61-0.88); p=0.001, and 3-year cumulative incidence (CI) of severe toxicity at 45% (41-49) in WBI vs 36% (32-40) in APBI arm. The difference was also in favor of APBI when considering breast skin toxicity alone: cs-HR=0.55 (0.44-0.70), p&lt; 0.001 and 3-year CI at 36% (32-40) in WBI vs 21% (18-25) in APBI arm. Conversely, for breast other toxicities, WBI was found less toxic than APBI: cs-HR= 2.10 (1.51-2.91), p&lt; 0.001, and 3-year CI at 8% (5-10) vs 15% (12-19), respectively. When considering cosmetic results according to the investigator, we observed no significant difference between the two arms: cs-HR=1.04 (0.81-1.33), p=0.26 and 3-year probability of remaining with good to excellent cosmetic results at 77% (73-81) in WBI arm and 78% (74-81) in APBI arm. Findings were similar when considering results according to the patient: cs-HR=1.07 (0.85-1.37), p=0.23, and 3-year probability at 74% (70-78) and 75% (70-79), respectively. Conclusions Historically SHARE is the first APBI trial that included hypofractionated schedules in the standard arm. We reported increased risk of severe toxicity and skin breast toxicity in standard arm as compared with APBI arm without any difference in terms of cosmetic results. Longer follow-up is needed.

Citation Format: Yazid Belkacemi, Isabelle Gabelle-Flandin, Marie-Cécile Le Deley, Adeline Petit, Philippe Guilbert, Julien Geffrelot, Christian Carrie, Eleonor Rivin Del Campo, Chantal Hanzen, Claire Charra-Brunaud, Isabelle Lecouillard, Nicolas Magne, Agnès Tallet, Nicolas Leduc, Blaha Belgadi, Philippe Fourneret, Alexandre Coutte, Esther Capelo, Franck Darloy, Muriel Garcia Ramirez, Philippe Dudouet, Pierre Clavere, Jean-Philippe Suchaud, Guillaume Auzac, Thomas Lacornerie, Jérôme Lemonnier, Céline Bourgier, Eric Lartigau. Early results of the French multicenter, randomized SHARE trial comparing whole breast irradiation versus accelerated partial breast irradiation in postmenopausal women with early-stage breast cancer. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD3-05.

Abstract P1-10-13: Economic comparison of standard external beam whole breast (WBI) versus accelerated partial breast irradiation (ABPI) in postmenopausal women with early-stage breast cancer. Results from the French SHARE randomized trial

Purpose: The economic evaluation reports the incremental cost utility ratio and budget impact of APBI vs standard external beam WBI for the treatment of post-menopausal women with early stage breast cancer.

Methods and materials: We compared 488 women in the standard arm (1 fraction per day delivered 5 days per week over 3 or 6/6.5 weeks) to 490 women in the ABPI arm (ten fractions delivered twice per day over one week). We took the perspective of the healthcare system, a 3-year time horizon; the outcomes were quality adjusted life years (QALYs). QALYs were calculated from the EQ5D5L questionnaires at baseline, 3 months, 6 months, 12 months and yearly after irradiation; scores were converted into utilities using the French value set and QALYs computed with the area under the curve approach. Measures of within-trial use of hospital resources were based on routine hospital data via patient-level information. We used the itemized and DRG cost data from each individual patient. Transportation costs were added in a sensitivity analysis. A 2.5% discount rate was applied to costs and QALYs. An incremental analysis with differences in costs and QALYs was performed to calculate the cost utility ratio. Bootstrapping was used to quantify uncertainty on the joint distribution of costs and outcomes, and 1,000 paired estimates of mean differential costs and QALYs were reported on a cost-effectiveness plane. A budget impact analysis based on incidence of breast cancer estimates was added. All analyses followed the intent to treat principle.

Results: Cost and utilities were available for the entire population. Costs and QALY results are presented in table 1. The 2 925 € (95% IC, -3 364 €; - 2 452 €) significant difference in total costs favoring ABPI was driven by the difference in radiotherapy costs and partly by lower transportation costs. No significant difference was found in QALYs. Figure 1 shows the uncertainty of the joint distribution of costs and QALYs. All replication are in the lower half of the plane indicating that ABPI is cost saving with QALYs distributed on each side of the vertical axis indicating equal distribution of QALYs. would be eligible for treatment with ABPI. The uptake of ABPI for 16% of these women would result in a 16 million€ cost saving.

Conclusions: At three years, ABPI for the treatment of postmenopausal women with early-stage breast cancer was found to be cost saving, with no difference in outcome measured by QALYs.

Table 1.

Figure 1.

Citation Format: Alicia Le Bras, Yazid Belkacemi, céline Bourgier, Isabelle Gabelle-Flandin, Adeline Petit, Philippe Guilbert, Julien Geffrelot, Christian Carrie, Eleonor RIVIN DEL CAMPO, Chantal Hanzen, claire charra-brunaud, Guillaume Auzac, Thomas Lacornerie, Jérôme Lemonnier, Eric Lartigau, Isabelle Durand-Zaleski. Economic comparison of standard external beam whole breast (WBI) versus accelerated partial breast irradiation (ABPI) in postmenopausal women with early-stage breast cancer. Results from the French SHARE randomized trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-10-13.

CANTO-RT: One of the Largest Prospective Multicenter Cohort of Early Breast Cancer Patients Treated with Radiotherapy including Full DICOM RT Data

This article describes the methodology used and provides a characterization of the study population in CANTO-RT (CANcer TOxicities RadioTherapy). CANTO (NCT01993498) is a prospective clinical cohort study including patients with stage I-III BC from 26 French cancer centers. Patients matching all CANTO inclusion and exclusion criteria who received RT in one of the 10 top recruiting CANTO centers were selected. Individual full DICOM RT files were collected, pseudo-anonymized, structured and analyzed on the CANTO-RT/UNITRAD web platform. CANTO-RT included 3875 BC patients with a median follow-up of 64 months. Among the 3797 patients with unilateral RT, 3065 (80.4%) had breast-conserving surgery, and 2712 (71.5%) had sentinel node surgery. Tumor bed boost was delivered in 2658 patients (68.5%) and lymph node RT in 1356 patients (35%), including internal mammary chain in 844 patients (21.8%). Most patients (3691 (95.3%)) were treated with 3D conformal RT. Target volumes, organs at risk contours and dose/volume histograms were extracted after quality-control procedures. CANTO-RT is one of the largest early BC prospective cohorts with full individual clinical, biological, imaging and DICOM RT data available. It is a valuable resource for the identification and validation of clinical and dosimetric predictive factors of RT and multimodal treatment-related toxicities.

Abstract P4-11-07: Improfib: Impact of radiotherapy on fatigue in breast cancer survivors

Background Fatigue is a common and disabling symptom experienced by patients (pts) after breast cancer (BC) treatment, significantly impacting their quality of life. However, this complex and multidimensional symptom often remains poorly managed. Previous studies identified some treatment-related factors associated with increased risk of developing severe and persistent fatigue. A better understanding of the relationship between treatment modalities and fatigue may help prevention and management strategies.Multimodal BC treatment often includes radiotherapy (RT) to the breast and/or nodal areas. RT modalities are now increasingly personalized. While an association between receipt of RT and fatigue after BC was previously suggested, large-scale data analyzing the impact of distinct RT modalities on fatigue are lacking.Our aim was to assess the impact of RT modalities on fatigue one year after treatment among patients with early-stage BC. Methods CANcer TOxicity (CANTO; NCT01993498) is a large multicentric nationwide prospective cohort of patients with stage I-III BC diagnosed from June 2012 to February 2017. The present analysis was performed in CANTO-RT, a sub-cohort of CANTO including 3875 patients who received RT in one of the 10 top recruiting CANTO centers. Among those patients, we selected 3797 patients who received unilateral RT.Our primary outcome was severe global fatigue 1 year after RT completion, defined by EORTC QLQ-C30 score ≥ 40/100. Secondary outcomes included severe physical, emotional and cognitive dimensions of fatigue (EORTC QLQ-FA12). The following RT-related variables were used as independent variables: Technique (3D vs IMRT), type of fractionation: Normofractionation (NF) vs Hypofractionation (HF), Boost to tumor bed (Yes vs No), Nodal RT (Yes vs No) and internal mammary chain (IMC) RT (Yes vs No). Multivariable logistic regression models assessed associations between RT-related variables and fatigue, adjusting for clinical, tumor, and BC treatment-related covariates collected at BC diagnosis. Results Our analytic cohort included 3797 patients. Among them, 2348 patients were postmenopausal (63%), 2030 received chemotherapy (52%), and 3068 endocrine therapy (81%). The prevalence of severe global fatigue 1 year after treatment was 33.3%. In addition, 33.1%, 20.4%, and 12.9% of patients reported severe physical, emotional and cognitive fatigue, respectively. Conformal 3D RT was delivered in 3635 patients (96%) mostly NF (2Gy/fraction) (n=2707; 93%). The majority of patients (n=2600; 68%) received a boost. Nodal RT was delivered in 1317 patients (35%) including 819 patients (22%) with IMC RT. After correction for age, BMI, comorbidities, income, smoke behavior, anxiety, depression, receipt of chemo and endocrine therapy, there was a significant relationship between specific RT modalities and severe global fatigue. Specifically, receipt of IMC RT (adjusted OR vs. no 1.57 [95% CI 1.10-2.25; p=0.0134]) and NF RT (adjusted OR vs. HF 1.77 [95% CI 1.01-3.11; p=0.048]) were associated with increased odds of severe global fatigue.In addition, there was a significant association between NF RT (adjusted OR vs. HF 1.75 [95% CI 1.01-3.07; p=0.049]) and an increased likelihood of severe physical fatigue, whereas none of the investigated RT modalities seemed to be associated with emotional and cognitive fatigue dimensions. Conclusions More than one third of patients in this RT-treated cohort reported severe fatigue 1 year after treatment. We found a significant association between RT modalities, such as IMC RT and NF, and increased likelihood of severe global fatigue. NF was also associated with physical fatigue. Our data add to the current understanding of treatment-related factors that can impact fatigue after BC, and inform personalized interventions to improve prevention and management of this disabling symptom.

Citation Format: Youssef Ghannam, Antonio Di Meglio, Thomas Sarrade, Alexandra Jacquet, Sibille Everhard, Youlia Kirova, Karine Peigneaux, Philippe Guilbert, Claire Chara-Brunaud, Julien Blanchecotte, Gilles Crehange, David Pasquier, Séverine Racadot, Céline Bourgier, Julien Geffrelot, Ahmed Benyoucef, Francois Paris, Guillaume Auzac, Inès Vaz-Luis, Sofia Rivera. Improfib: Impact of radiotherapy on fatigue in breast cancer survivors [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-11-07.

Abstract P3-19-01: CANTO RT: The largest prospective multicenter cohort of early breast cancer patients treated with radiotherapy including full DICOM RT data

Purpose: In this paper, we describe the methodology used, and provide a first characterization of the study population and radiotherapy (RT) data in CANTO-RT (CANcer TOxicities Radiotherapy), the largest available multicenter prospective cohort of early breast cancer (BC) patients treated with RT that aims to identify predictors of development, and persistence of long-term toxicities. Methods: CANTO (NCT01993498) is a French prospective clinical cohort study of 10 150 patients with stage I-III BC from 26 cancer centers. Patients matching all CANTO inclusion and exclusion criteria, who received RT and were still in follow up, in the 10 top recruiting CANTO centers, with a minimum follow up of 3 years, were selected for CANTO-RT. Eligible patients had breast/chest wall +/- lymph node RT with curative intent. Individual full DICOM RT files (CT, RT Structure, RT Dose, RT Plan) were collected, anonymized, structured and analyzed on the CANTO-RT/UNITRAD web platform using AQUILAB Share Place™ and Analytics Dose module. Characteristics of the patients and tumors (including TNM, histology, HER2, estrogen and progesterone receptor) were recorded at baseline. Characteristics of the treatments, skin, lung, cardiovascular, neurological, musculoskeletal toxicities (CTCAE v4.0), QOL (BR23, QLQC30), cosmetic, and oncological outcomes were assessed at diagnosis (baseline), 3-6 (M0), 12 (M12), 36 (M36) and 60 (M60) months after completion of primary surgery, chemotherapy or radiotherapy whichever came last together, with blood, plasma and serum tests. Results: CANTO-RT enrolled 3875 BC patients between June 2012 and February 2017 with a median follow-up of 64 months :1947 (50.2%) left side, 1850 (47.8%) right side and 78 (2%) bilateral BC. The vast majority of patients had hormone receptor-positive tumors 3321 (85.7%) and 553 (14.3%) had human epidermal growth factor 2 (HER2) positive tumors; 2586 (66.7%) had stage pT1 and 2525 (65.2%) pN0 disease; 2087 (53.8%) neoadjuvant or adjuvant chemotherapy, 477 (12.3%) adjuvant trastuzumab and 3138 (81%) adjuvant endocrine therapy. Among 3797 patients with unilateral RT, 3065 (80.4%) had breast conserving surgery, 747 (19.6%) total mastectomy; 2712 (71.5%) sentinel node and 1080 (28.5%) axillary dissection. Tumor bed boost was delivered in 2658 patients (68.5%) and lymph node RT in 1356 patients (35%) including internal mammary chain in 844 patients (21.8%). Most patients 3691 (95.3%) were treated with 3D conformal RT and 184 (4.7%) with intensity-modulated RT. Normofractionated RT (2Gy/fraction) was mostly used (69.9%). Clinical target (breast, chest wall, lymph nodes) and contoured organs at risk (heart, left anterior descending coronary, lung, spinal cord, esophagus, thyroid, brachial plexus, contralateral breast, humeral head) contours and dose/volume histograms were automatically extracted after quality control procedure excluding corrupted files and inconsistencies 36 (1%) (Table 1). Conclusion: CANTO-RT is the largest early breast cancer prospective cohort with full individual clinical and DICOM RT data available. CANTO-RT is a valuable resource, open for collaborative projects, for identification and validation of clinical and dosimetric predictive factors of RT related toxicities. Further long term follow up is ongoing.

Table 1.Baseline characteristics of the CANTO RT breast cancer patients.CharacteristicsBreast Cancer Patients [N(%) or Mean (range)]Age at enrolmentMean (range), years56.5 (23.3-85.8)Tumour size (pT)T037 (1)T12586 (66.7)T21058 (27.3)T3177 (4.6)Missing17 (0.4)Nodal status (pN)02525 (65.2)11035 (26.7)2223 (5.8)379 (2)Missing13 (0.3)Tumour histologyInfiltrating Ductal3011 (77.7)Lobular473 (12.2)Others (including mixed)381 (9.8)Missing10 (0.3)Hormone Receptors positiveNegative541 (14)Positive3321 (85.7)Missing13 (0.3)HER2Negative3305 (85.3)Positive553 (14.3)Missing17 (0.4)Type of chemotherapyNo chemotherapy1788 (46.1)Neoadjuvant chemotherapy450 (11.6)Adjuvant chemotherapy1629 (42)Peri-adjuvant chemotherapy (neo + adjuvant)8 (0.2)Hormonal therapyNo730 (18.8)Yes3138 (81)Missing7 (0.2)Herceptin treatmentNo or Not applicable3378 (87.2)Yes477 (12.3)Missing20 (0.5)Type of breast surgerylumpectomy3113 (80.3)Mastectomy734 (18.9)Right lumpectomy and Left mastectomy13 (0.3)Right mastectomy and Left lumpectomy9 (0.2)None6 (0.2)Type of lymph node surgerySentinel node2746 (70.9)Axillary dissection1086 (28)Right sentinel node, Left axillary dissection20 (0.5)Right axillary dissection, left sentinel node12 (0.3)None11 (0.3)Radiation therapyRight Side1850 (47.8)Left Side1947 (50.2)Bilateral78 (2.0)Patients with boostNo or Not applicable1217 (31.4)Yes2658 (68.6)Lymph node levels treatedNone2519 (65)Yes1356 (35)Level 1284 (20.9)Level 2340 (25.1)Level 31072 (79.1)Level 41348 (99.4)Internal mammary chain844 (62.2)Irradiation techniques3D3691 (95.3)IMRT184 (4.7)Fractionation regimensNormofractionation 25-fractions2707 (69.9)Hypofractionation 15-16 fractions166 (4.3)Hypofractionation and Partial breast irradiation51 (1.3)Unspecified fractionation - CTV breast or chest wall not delineated951 (24.5)

Citation Format: Thomas Sarrade, Rodrigue Allodji, Youssef Ghannam, Guillaume Auzac, Sibille Everhard, Ophélie Querel, Youlia Kirova, Karine Peignaux, Philippe Guilbert, Claire Charra-Brunaud, Julien Blanchecotte, Rezart Belshi, David Pasquier, Séverine Racadot, Céline Bourgier, Sandrine Ducornet, David Gibon, Fabrice André, Florent De Vathaire, Sofia Rivera. CANTO RT: The largest prospective multicenter cohort of early breast cancer patients treated with radiotherapy including full DICOM RT data [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-01.

Prospective evaluation of intensity-modulated radiotherapy toxicity in extremity soft tissue sarcomas patients: A role for irradiated healthy soft tissue volume?

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Toxicity assessment in ESTS patients who received IMRT in real-life practice.

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Prospective evaluation by confidential mailed survey.

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Healthy soft tissue segment volume (median: 3911 cm³) associated with decreased toxicities.

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This should be confirmed as a possible dosimetric constraint.

Aim

To prospectively assess toxicities of curative-intent intensity-modulated conformal radiotherapy (IMRT) in patients with extremity soft tissue sarcomas (ESTS).

Methods

Data from 59 consecutive patients with ESTS between 2014 and 2019 were both retrospectively and prospectively analysed. Toxicity data were collected both by confidential mailed survey (39% completed) and medical charts, and graded according to CTCAE v5.0. Normal tissues dosimetric data (healthy soft tissue segment, joint and bone) were included. The healthy soft tissue segment was created by adding 5 cm on either side of the PTV on CT axial slices, the PTV and bone (and articulation if present) were then removed from the generated volume.

Results

IMRT was delivered post-operatively for nearly half of patients (n = 24, 41%), preoperatively for 18 (31%) and exclusively for 17 (28%; salvage: 13% or immediately inoperable: 15%). The median total dose delivered to the planned target volume (PTV) was 50.4 Gy (36–68 Gy) and 13 patients (22%) received a boost. With a median follow-up of 27 months (6–94 months), a total of 87 late effects were identified in 44/59 (75%) patients: 89% G1–2, and 11% G3–4. The main G1-2 toxicities were: functional limitation (36%), oedema (29%), gait disorders (20%), neurological disorders (20%) and chronic pain (32%). G3-4 toxicities were pain (n = 2), arterial stricture (n = 1) and a chronic wound requiring skin graft (n = 2). No bone fracture was observed. Quality of life was rated as good or very good in 70% patients who completed the survey. Larger (>3500 cm³) healthy soft tissue segment volume was associated with decreased late toxicities (p = 0.02). No other predictive factor of toxicity was identified. The 2-year rates of local control, overall survival and recurrence-free survival were 90%, 90% and 64%, respectively.

Conclusion

Healthy soft tissue segment volume influenced toxicity. Long-term prospective monitoring in a homogeneous population remains critical to assess the impact of IMRT induced chronic toxicity in ESTS patients. This should ideally lead to a validated normal tissue dose constraint (e.g.: healthy soft tissue segment volume > 3500 cm³) to recommend for practitioners to help reduce the late toxicity risk.

Tumour motion management in lung cancer: a narrative review

Respiratory motion is one of the geometrical uncertainties that may affect the accuracy of thoracic radiotherapy in the treatment of lung cancer. Accounting for tumour motion may allow reducing treatment volumes, irradiated healthy tissue and possibly toxicity, and finally enabling dose escalation. Historically, large population-based margins were used to encompass tumour motion. A paradigmatic change happened in the last decades led to the development of modern imaging techniques during the simulation and the delivery, such as the 4-dimensional (4D) computed tomography (CT) or the 4D-cone beam CT scan, has contributed to a better understanding of lung tumour motion and to the widespread use of individualised margins (with either an internal tumour volume approach or a mid-position/ventilation approach). Moreover, recent technological advances in the delivery of radiotherapy treatments (with a variety of commercial solution allowing tumour tracking, gating or treatments in deep-inspiration breath-hold) conjugate the necessity of minimising treatment volumes while maximizing the patient comfort with less invasive techniques. In this narrative review, we provided an introduction on the intra-fraction tumour motion (in both lung tumours and mediastinal lymph-nodes), and summarized the principal motion management strategies (in both the imaging and the treatment delivery) in thoracic radiotherapy for lung cancer, with an eye on the clinical outcomes.

Five-Year Results of the Preoperative Accelerated Partial Breast Irradiation (PAPBI) Trial

PURPOSE

In this multicenter phase 2 feasibility study, we investigated the impact of preoperative accelerated partial breast irradiation (PAPBI) on local control, breast fibrosis, and cosmetic outcome.

METHODS AND MATERIALS

Women aged >60 years with an invasive, unifocal (mammography and magnetic resonance imaging), nonlobular adenocarcinoma of the breast were treated with PAPBI. Six weeks after radiation therapy, a wide local excision was performed. Radiation therapy consisted of 10 × 4 Gy (2010-2013) or 5 × 6 Gy (after 2013) to the tumor (gross target volume) with a 25 mm margin (20 mm from gross target volume to clinical target volume, 5 mm planning target volume).

RESULTS

One hundred thirty-three patients treated between 2010 and 2016 were analyzed with a median follow-up of 5.0 years (0.9-8.8 years). Seventy-eight (59%) patients were treated with 10 × 4 Gy in 2 weeks and 55 (41%) patients with 5 × 6 Gy in 1 week. Eighteen postoperative complications (14%) occurred in 15 patients (11%). The proportion of patients with no to mild fibrosis in the treated part of the breast at 2 years and later time points was around 90%. Cosmesis improved over time in several patients: excellent to good cosmetic score as rated by the physician was 68% at 6 months and 92% at 5 years. Seventy-seven percent (6 months) to 82% (5 years) of patients were "satisfied" or "very satisfied" with their cosmetic outcome. Three recurrences were detected in the biopsy track and 1 recurrence in the ipsilateral breast.

CONCLUSIONS

PAPBI is a feasible method with a low postoperative complication rate, limited fibrosis, and good to excellent cosmetic outcome. The local recurrence rate was 3% at 5 years; however, no local recurrences were observed since removal of the needle biopsy track.

Evaluation of MVCT imaging dose levels during helical IGRT: comparison between ion chamber, TLD, and EBT3 films

The purpose of this investigation was to evaluate the dose on megavoltage CT (MVCT) images required for tomotherapy. As imaging possibilities are often used before each treatment and usually used several times before the session, we tried to evaluate the dose delivered during the procedure. For each scanning mode (fine, normal, and coarse), we first established the relative variation of these doses according to different technical parameters (explored length, patient setup). These dose variations measured with the TomoPhant, also known as Cheese phantom, showed the expected variations (due to the variation of scattered radiation) of 15% according to the explored length and ± 5% according to the phantom setup (due to the variation of the point of measurement in the bore). In order to estimate patient doses, an anthropomorphic phantom was used for thermoluminescent and film dosimetry. The degree of agreement between the two methods was very satisfactory (the differences correspond to 5 mGy per imaging session) for the three sites studied (head & neck, thorax, and abdomen). These measurements allowed us to estimate the delivered dose of between 1 cGy and 4 cGy according to the site and imaging mode. Finally, we attempted to investigate a way to calculate this delivered dose in our patients from the study conducted on a cylindrical phantom and by taking into account data from the initial kV-CT scan. The results we obtained were close to our measurements, with discrepancies below 5 mGy per MVCT.

SHARE: a French multicenter phase III trial comparing accelerated partial irradiation versus standard or hypofractionated whole breast irradiation in breast cancer patients at low risk of local recurrence

The standard treatment for breast cancer patients at low risk of recurrence is based on conservative surgery followed by radiation therapy delivered to the whole breast. The accelerated partial breast irradiation (APBI) concept, developed more than 15 years ago, could be an option in selected patients. However, the ideal patient profile for APBI is still not clearly identified. Recent reports from the American Society for Radiation Oncology (ASTRO) and the Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) have suggested selection criteria for "suitable patients" who could receive APBI outside of clinical trials. Currently, there are 6 ongoing phase III trials. All are characterized by a significant heterogeneity regarding inclusion criteria and stratification factors. The French UNICANCER trial (SHARE; ClinicalTrials.gov identifier NCT01247233) will randomize 2,800 patients in 3 arms: APBI (1 week) using 3-dimensional (3D) conformal radiotherapy, standard radiotherapy (6.5 weeks), and hypofractionated radiotherapy (3 weeks). In this article, we review the reported retrospective studies as well as older randomized trials. We will also describe the differences between the 6 ongoing phase III trials and the particularities of the French SHARE trial.

Abstract OT1-2-02: SHARE. A French multiceter phase III trial comparing accelerated partial irradiation (APBI) versus standard or hypofractionated whole breast irradiation in low risk of local recurrence breast cancer

Introuction: The six worldwilde ongoing APBI phase III trials are characterized by a significant heterogeneity regarding inclusion criteria and stratifications. One non-inferiority trial (SHARE) is currently ongoing in France.

SHARE Trial design: SHARE will randomize 2800 patients in 3 arms: standard (Arm A; 6.5 weeks) versus hypofractionated (Arm B; 3 weeks) versus APBI (Arm C; 1 week) using only 3D conformal radiotherapy (3D CRT). In this trial high quality and homogeneous criteria in surgery, pathology and RT for the 3 arms is planed.

Primary objective: To estimate and compare the rates of local recurrences between the experimental and control arms.

Inclusion criteria

Post menopausal women aged ≥ 50y (stratification: &lt; 70 yrs vs ≥ 70 yrs)

Menopausal status confirmed since ≥ 12 months (Clinically and/or biologically)

No previous ipsilateral breast and/or mediastinal irradiation

Pathologic confirmation of invasive carcinoma (all types of invasive carcinomas)

Unifocal tumor confirmed on the pathologic specimen

Pathologic tumor size of the carcinoma ≤ 2cm (including the in situ component)

All pathologic grades (stratification: HER2/triple negative vs others)

Clear lateral margins confirmed on the final pathology report. The minimal size from the invasive and in situ disease should be 2 mm (≥ 2mm) pN0 (i+/−) (stratification: pN0 vs pN(i+))

Chemotherapy and trastuzumab are not allowed - RT should be started ≥ 4weeks and ≤ 12 weeks after surgery (including the date of second excision for close or involved margins)

Clips in the tumor bed placed during surgery (4 to 5 clips)

Treatment

Arm A

3D CRT should be started within 12 weeks after the last surgery. A total of 50 Gy is delivered in 25 fractions, one fraction of 2 Gy per day, 5 days a week. In this arm, the boost of 10 to 16 Gy is delivered in 5 to 8 fractions.

Dose prescription (arm B)

The main point is that in both schedules the total dose is delivered in 3 weeks: – The Canadian schedule described by Whelan et al. delivers 42.5 Gy in 16 fractions (2.65Gy/fraction, 5 fractions/week).– The UK schedule, reported in START B trial delivers 40 Gy in 15 fractions (2.66 Gy/ fraction, 5 fractions/week). Nodal and boost RT is not allowed.

Arm C

3D CRT should be started within 12 weeks after the last surgery. Intensity modulated RT (IMRT) and brachytherpayare not allowed. A total dose of 40 Gy in 10 fractions over 1 week (4Gy per fraction twice a day with minimal delay of 6h).

Conclusion: In summary, the French trial will allow: – Selected patients according to age and low risk of local recurrence parameters.– To evaluate in a subgroup of patients (4 to 5 centers), the impact of magnetic resonance imaging (MRI) for patient selection and the rate of occult disease (multifocality) not detected by standard imaging evaluation which is considered as an exclusion criteria.– To determine APBI parameters adapted to the surgical procedure in the tumor bed remodeling setting.– To determine homogeneous criteria for the surgical procedure, minimal requirements and optimal criteria that have to be mentioned in the final pathology report in all 3 arms of the study.– To test hypofractionation using 3 weeks-schedules as compared to APBI

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT1-2-02.