Evaluating Acute Radiation-Induced Dermatitis in Breast Cancer Patients Undergoing Postoperative Radiotherapy: Insights from a Case Study

Radiation-induced dermatitis (RID) is a significant side effect experienced by breast cancer patients undergoing radiotherapy. As radiation plays a crucial role in breast cancer treatment, understanding the impact of various radiotherapy techniques on RID is essential for enhancing patient care. This case study focuses on evaluating the acute RID profile in breast cancer patients who underwent postoperative radiotherapy using a tangential split-rapid arc technique with the FAST-FORWARD protocol. The goal was to assess the severity and management of skin reactions, a key concern for patients receiving radiation.

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Purpose of the Study

The primary objective of the study was to evaluate the profile of acute radiation-induced dermatitis (RID) in breast carcinoma patients receiving postoperative radiotherapy. Specifically, it aimed to understand the impact of tangential split-rapid arc radiation techniques combined with the FAST-FORWARD protocol on RID. This approach was applied to the whole breast and chest wall after mastectomy or breast conservation surgery. Additionally, the study aimed to investigate the potential correlation between factors such as breast size and boost volume and the severity of RID, particularly in patients with larger breast volumes.

Materials and Methods

This prospective study included 19 consecutive breast cancer patients with pathological stages T1-3, N1-2, who were planned for adjuvant radiotherapy after surgery. The patients received radiotherapy using the FAST-FORWARD schedule, which involved a hypofractionated dose of 26 Gy delivered in 5 fractions over the course of one week.

Out of the 19 patients, 7 had undergone breast-conserving surgery (BCS) and received a simultaneous integrated boost (SIB) of 32 Gy in 5 fractions to the tumor bed. Importantly, none of the patients received a sequential boost, which is a common practice in conventional radiotherapy. The remaining 12 patients had undergone mastectomies and received radiotherapy to the chest wall.

The radiotherapy plan for each patient included contouring of the chest wall, regional lymph nodes, and organs at risk (OARs), such as the ipsilateral lung and heart, following the European Organisation for Research and Treatment of Cancer (EORTC) guidelines. A bi-tangential split-rapid arc technique was used to deliver radiation to the planned targets.

To evaluate acute toxicity, particularly RID, patients were assessed at several time points: at the completion of treatment (Day 5), 15 days post-treatment, 1 month post-treatment, and 3 months post-treatment. Skin reactions such as pigmentation, erythema, and desquamation were documented and graded according to the Common Terminology Criteria for Adverse Events (CTCAE) system.

Dosimetric Planning and Challenges

One of the key challenges identified during the study was the difficulty in achieving mandatory dosimetric criteria, particularly for left-sided chest wall radiotherapy and cases where internal mammary lymph nodes (IMLN) were contoured separately. The difficulty stemmed from the need to balance target coverage while minimizing dose exposure to organs at risk, especially the heart and lungs.

For left-sided breast cancer patients, the proximity of the heart and lungs to the radiation field presents a unique challenge. High doses to these critical organs can lead to long-term complications, including cardiopulmonary issues. Therefore, ensuring that radiation doses to these organs are kept within safe limits is crucial.

Despite these challenges, the study aimed to adhere to dosimetric criteria to the best possible extent. However, it was noted that patients with larger breast volumes and those requiring a tumor bed boost close to the skin surface faced a higher risk of developing more severe RID.

Results

The study yielded promising results, with the majority of patients experiencing only mild acute radiation-induced dermatitis. Out of the 19 patients, only one patient (1/7) in the breast-conservation cohort experienced grade 3 RID, which is considered a severe form of dermatitis. Interestingly, none of the 12 patients who received chest wall radiotherapy developed grade 3 or higher toxicity.

The patient who developed grade 3 RID had a breast volume exceeding 800 cc and a tumor bed boost volume greater than 20 cc. Additionally, this patient received a maximum dose (Dmax) greater than 109%, which may have contributed to the severity of the dermatitis. However, no statistically significant correlation was found between breast size or boost volume and the occurrence of grade 3 dermatitis, likely due to the small sample size of the study.

The absence of severe dermatitis in the chest wall cohort suggests that the tangential split-rapid arc technique, when applied with the FAST-FORWARD protocol, is effective in minimizing acute skin reactions in mastectomy patients. This finding is particularly relevant for patients who are concerned about the cosmetic and quality-of-life implications of severe radiation dermatitis.

Discussion

The results of this case study suggest that the use of extreme hypofractionated adjuvant radiotherapy, with or without a simultaneous integrated boost, is a feasible and safe approach for breast cancer patients. The tangential split-rapid arc technique, combined with the FAST-FORWARD protocol, appears to offer favorable outcomes in terms of minimizing acute radiation dermatitis..

One of the key takeaways from the study is the importance of caution when treating patients with larger breast volumes. As seen in the case of the patient with grade 3 RID, larger breast size and proximity of the tumor bed to the skin surface can increase the risk of severe dermatitis. This highlights the need for careful dosimetric planning and possibly customized treatment approaches for such patients.

Furthermore, the study underscores the potential of the FAST-FORWARD protocol as a viable alternative to conventional radiotherapy schedules. By delivering a higher dose of radiation in fewer fractions, this approach offers the advantages of reduced treatment duration and improved patient convenience. However, larger studies are needed to confirm the long-term safety and efficacy of this technique, particularly in terms of late-onset toxicities.

Conclusion

This case study provides valuable insights into the management of radiation-induced dermatitis in breast cancer patients undergoing postoperative radiotherapy. The tangential split-rapid arc technique, combined with the FAST-FORWARD protocol, demonstrated a favorable acute RID profile, with most patients experiencing only mild dermatitis. While the study was limited by its small sample size, the findings suggest that this approach is safe and effective, particularly for patients with smaller breast volumes.

However, caution should be exercised when treating patients with larger breast sizes, as they may be at higher risk of developing severe dermatitis. Further research involving larger patient populations is needed to validate these findings and explore potential strategies for optimizing radiotherapy outcomes in breast cancer patients.