Systematic risk analysis of radiation pneumonitis in breast cancer: role of cotreatment with chemo-, endocrine, and targeted therapy

Automated segmentation in planning-CT for breast cancer radiotherapy: A review of recent advances

Postoperative radiotherapy (RT) has been shown to effectively reduce disease recurrence and mortality in breast cancer (BC) treatment. A critical step in the planning workflow is the accurate delineation of clinical target volumes (CTV) and organs-at-risk (OAR). This literature review evaluates recent advancements in deep-learning (DL) and atlas-based auto-contouring techniques for CTVs and OARs in BC planning-CT images for RT. It examines their performance regarding geometrical and dosimetric accuracy, inter-observer variability, and time efficiency. Our findings indicate that both DL- and atlas-based methods generally show comparable performance across OARs and CTVs, with DL methods slightly outperforming in consistency and accuracy. Auto-segmentation of breast and most OARs achieved robust results in both segmentation quality and dosimetric planning. However, lymph node levels (LNLs) presented the greatest challenge in auto-segmentation with significant impact on dosimetric planning. The translation of these findings into clinical practice is limited by the geometric performance metrics and the lack of dose evaluation studies. Additionally, auto-contouring algorithms showed diverse structure sets, while training datasets varied in size, origin, patient positioning and imaging protocols, affecting model sensitivity. Guideline inconsistencies and varying definitions of ground truth led to substantial variability, suggesting a need for a reliable consensus training dataset. Finally, our review highlights the popularity of the U-Net architecture. In conclusion, while automated contouring has proven efficient for many OARs and the breast-CTV, further improvements are necessary in LNL delineation, dosimetric analysis, and consensus building.

Radiation Pneumonitis After Partial Breast Irradiation

This case presentation describes development of symptomatic radiation pneumonitis in a healthy woman who underwent partial breast irradiation with deep inspiration breath hold for early stage breast cancer meeting all published dose constraints. Risk factors for, diagnosis and management of radiation pneumonitis are discussed in detail. Radiation pneumonitis is rare, ranging from <1% to 1.5% (when regional nodal irradiation is included). Partial breast irradiation spares breast tissue, but may not spare lung tissue better than whole breast irradiation, depending upon treatment technique such as prone positioning. Dose constraints for normal and target structures from published trials are reviewed, however data specifically relating to pneumonitis in partial breast trials are limited.

Patient-reported symptoms before adjuvant locoregional radiotherapy for breast cancer: triple-negative histology impacts the symptom burden

BACKGROUND

Multimodal breast cancer treatment may cause side effects reflected in patient-reported outcomes and/or symptom scores at the time of treatment planning for adjuvant radiotherapy. In our department, all patients have been assessed with the Edmonton Symptom Assessment System (ESAS; a questionnaire addressing 11 major symptoms and wellbeing on a numeric scale of 0-10) at the time of treatment planning since 2016. In this study, we analyzed ESAS symptom severity before locoregional radiotherapy.

PATIENTS AND METHODS

Retrospective review of 132 patients treated between 2016 and 2021 (all comers in breast-conserving or post-mastectomy settings, different radiotherapy fractionations) was performed. All ESAS items and the ESAS point sum were analyzed to identify subgroups with higher symptom burden and thus need for additional care measures.

RESULTS

The biggest patient-reported issues were fatigue, pain, and sleep problems. Patients with triple negative breast cancer reported a higher symptom burden (mean 30 versus 20, p = 0.038). Patients assigned to adjuvant endocrine therapy had the lowest point sum (mean 18), followed by those on Her-2-targeting agents without chemotherapy (mean 19), those on chemotherapy with or without other drugs (mean 26), and those without systemic therapy (mean 41), p = 0.007. Those with pathologic complete response after neoadjuvant treatment had significantly lower anxiety scores (mean 0.7 versus 1.8, p = 0.03) and a trend towards lower depression scores, p = 0.09.

CONCLUSION

Different surgical strategies, age, and body mass index did not impact on ESAS scores, while the type of adjuvant systemic therapy did. The effect of previous neoadjuvant treatment and unfavorable tumor biology (triple negative) emerged as important factors associated with symptom burden, albeit in different domains. ESAS data may facilitate identification of patients who should be considered for additional supportive measures to alleviate specific symptoms.

Phosphate Coordination to Metal-Organic Layer Secondary Building Units Prolongs Drug Retention for Synergistic Chemoradiotherapy

Chemoradiotherapy combines radiotherapy with concurrent chemotherapy to potentiate antitumor activity but exacerbates toxicities and causes debilitating side effects in cancer patients. Herein, we report the use of a nanoscale metal-organic layer (MOL) as a 2D nanoradiosensitizer and a reservoir for the slow release of chemotherapeutics to amplify the antitumor effects of radiotherapy. Coordination of phosphate-containing drugs to MOL secondary building units prolongs their intratumoral retention, allowing for continuous release of gemcitabine monophosphate (GMP) for effective localized chemotherapy. In the meantime, the MOL sensitizes cancer cells to X-ray irradiation and provides potent radiotherapeutic effects. GMP-loaded MOL (GMP/MOL) enhances cytotoxicity by 2-fold and improves radiotherapeutic effects over free GMP in vitro. In a colon cancer model, GMP/MOL retains GMP in tumors for more than four days and, when combined with low-dose radiotherapy, inhibits tumor growth by 98 %. The synergistic chemoradiotherapy enabled by GMP/MOL shows a cure rate of 50 %, improves survival, and ameliorates cancer-proliferation histological biomarkers.

Radiation therapy of breast cancer in the Nahe Breast Center: first results of an analysis in the context of health services research

BACKGROUND

The first evaluation of radiotherapy results in patients with breast cancer treated as part of a multimodal oncologic therapy in the Nahe Breast Center is presented. Analysis of the results was performed using an in-practice registry.

PATIENTS AND METHODS

From September 2016 to December 2017, 138 patients (median age 62.5 years; range 36-94 years) with breast cancer (right side, n = 67; left side, n = 71) received adjuvant radiation therapy. Of these, 103 patients received gyneco-oncologic care at the Nahe Breast Center, and 35 were referred from outside breast centers. The distribution into stages was as follows: stage I, n = 48; stage II, n = 68; stage III, n = 19; stage IV, n = 3. Neoadjuvant chemotherapy was given to 19 and adjuvant chemotherapy to 50 patients. Endocrine treatment was given to 120 patients. Both 3D conformal (n = 103) and intensity-modulated (n = 35) radiotherapy were performed with a modern linear accelerator.

RESULTS

With a median follow-up of 60 months (1-67), local recurrence occurred in 4/138 (2.9%) and distant metastasis in 8/138 (5.8%) patients; 7/138 (5.1%) patients died of their tumors during the follow-up period. The actuarial 5‑year local recurrence-free survival of all patients was 97.1%, and the actuarial 5‑year overall survival of all patients was 94.9%. We observed no grade 3 or 4 radiogenic side effects.

CONCLUSION

The results of radiotherapy for breast carcinoma at the Nahe Breast Center are comparable to published national and international results. In particular, the local recurrence rates in our study, determined absolutely and actuarially, are excellent, and demonstrate the usefulness of radiotherapy.

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

Backgrounds

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.

Methods

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.

Results

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).

Conclusion

Patients with IBBR achieved better radiation dosimetry distribution and higher quality of life without more complications of radiotherapy.

Ex Vivo Chromosomal Radiosensitivity Testing in Patients with Pathological Germline Variants in Breast Cancer High-Susceptibility Genes BReast CAncer 1 and BReast CAncer 2

BACKGROUND

Individual radiosensitivity is an important factor in the occurrence of undesirable consequences of radiotherapy. The potential for increased radiosensitivity has been linked to highly penetrant heterozygous mutations in DNA repair genes such as BRCA1 and BRCA2. By studying the chromosomal radiosensitivity of BRCA1/2 mutation carriers compared to the general population, we study whether increased chromosomal radiation sensitivity is observed in patients with BRCA1/2 variants.

METHODS

Three-color-fluorescence in situ hybridization was performed on ex vivo-irradiated peripheral blood lymphocytes from 64 female patients with a heterozygous germline BRCA1 or BRCA2 mutation. Aberrations in chromosomes #1, #2 and #4 were analyzed. Mean breaks per metaphase (B/M) served as the parameter for chromosomal radiosensitivity. The results were compared with chromosomal radiosensitivity in a cohort of generally healthy individuals and patients with rectal cancer or breast cancer.

RESULTS

Patients with BRCA1/2 mutations (n = 64; B/M 0.47) overall showed a significantly higher chromosomal radiosensitivity than general healthy individuals (n = 211; B/M 0.41) and patients with rectal cancer (n = 379; B/M 0.44) and breast cancer (n = 147; B/M 0.45) without proven germline mutations. Chromosomal radiosensitivity varied depending on the locus of the BRCA1/2 mutation.

CONCLUSIONS

BRCA1/2 mutations result in slightly increased chromosomal sensitivity to radiation. A few individual patients have a marked increase in radiation sensitivity. Therefore, these patients are at a higher risk for adverse therapeutic consequences.

Does shortening the duration of radiotherapy treatment in breast cancer increase the risk of radiation pneumonia: A retrospective study

Randomized studies evaluating hypofractionation and conventional fractionation radiotherapy treatments (RT) in patients with breast cancer have shown that hypofractionation achieves similar results to conventional fractionation in terms of survival and local control rates. It has also been shown that their long-term toxicities are similar. This study aimed to evaluate the effects of hypofractionated radiotherapy (H-RT) and conventional radiotherapy (C-RT) on lung toxicity and identify factors affecting this toxicity in patients with breast cancer. The study included 118 patients who underwent adjuvant RT following breast-conserving surgery (BCS). Out of these, 63 patients were assigned to receive C-RT, while the remaining 55 were assigned to receive H-RT. To clarify, we treated 63 patients with C-RT and 55 patients with H-RT. 60 patients were treated using 3-dimensional conformal radiotherapy (3DCRT) and 58 patients were treated using intensity modulated radiotherapy (IMRT). The patients were evaluated weekly for toxicity during radiotherapy (RT) treatment and were called every 3 months for routine controls after the treatment. The first control was performed 1 month after the treatment. Statistical analysis was performed using the SPSS20 program, and a P value of <.005 was considered statistically significant. The study found that the median age of the participants was 54.9 years and tomographic findings were observed in 70 patients. Radiological findings were detected at a median of 5 months after RT. The mean lung dose (MLD) on the treated breast side (referred to as ipsilateral lung or OAR) was 10.4 Gy for the entire group. Among patients who received 18 MV energy in RT, those with an area volume (V20) of the lung on the treated breast side >18.5%, those with a mean dose of the treated breast side lung (ipsilateral lung) >10.5 Gy, and those who received concurrent hormone therapy had significantly more tomographic findings. However, patients treated with YART had fewer tomographic findings. No symptomatic patients were observed during the follow-up period. Our findings show that the risk of lung toxicity is similar with H-RT and C-RT, and H-RT can be considered an effective and safe treatment option for breast cancer. The key factors affecting the development of lung toxicity were found to be the type of RT energy used, RT to the side breast, volume receiving 20 Gy in the side lung, side lung mean dose, and simultaneous hormonal therapy.