A Retrospective Dosimetric Study in Breast Cancer Patients Who Received Conformal Radiation Therapy for Achievability of Recommended Dose Constraints of RTOG, DBCG, EORTC for Lung and Heart

PURPOSE/OBJECTIVE(S)

In India, carcinoma of breast is the commonest malignancy among women. In multidisciplinary approach of its management, radiotherapy (RT) is an important component. Different cooperative groups have defined dose constraints to lungs and heart to minimize these late side effects such as radiation pneumonitis and coronary artery disease. To assess the achievability of dose constraints given for lung and heart by RTOG, EORTC and DBCG in our cohort of breast cancer patients who underwent conformal radiation therapy to chest wall / breast along with supraclavicular nodal region.

MATERIALS/METHODS

This retrospective dosimetric study included all breast cancer patients who underwent conformal radiation in our institute from Jan 2021 to Dec 2022 and was treated with a dose of 40 Gy in 15 fractions.

RESULTS

A total of 302 patients (162 - Left sided, 140 - Right sided) were in the study cohort. Majority of them received RT with 3DCRT with FiF (266 patients) and 36 patients received RT by VMAT technique. Respiratory gating was done in left sided breast cancer by DIBH for 46.2 % of patients due to COVID pandemic during this period. Our analysis showed that for the ipsilateral lung, EORTC (77.8%) dose constraints were easy to achieve followed by DBCG (65.2%) and RTOG (61.9 %). For the heart constraints in left sided breast cancer patients, easily achievable constraints were by DBCG (91.9 %) followed by RTOG (66.6 %) and EORTC (53.1%). The DBCG constraints of Dmean <5 Gy was more liberal than any other recommendations. All the dose constraint recommendations were easily achieved for heart in right sided breast cancer patients, by more than 90 % of the population. Usage of respiratory gating with DIBH technique improves the rates of achievability of lung constraints in 56 (74.6%) out of 75 patient and heart constraints in 54 (72 %) out of 75 patients. Our institutional policy is to treat chest wall / breast along with supraclavicular nodal chain in case of NACT or T3/T4 disease and this could have been the reason why we were unable to achieved the dose constraints recommended.

CONCLUSION

The DBCG dose constraint recommendations for heart was achieved in the left chest wall treatment in majority of women and EORTC was best achieved for ipsilateral lung. All heart dose constraint recommendations were achieved for right chest wall treatment. Respiratory gating improves achievability rates of the recommendations. It is difficult to achieve all the dose constraints as recommended by different cooperative groups as there is variation among them.

Primary pulmonary synovial sarcoma: A clinicopathological study of 22 cases

INTRODUCTION

Primary pulmonary synovial sarcoma (PPSS) is a rare mesenchymal tumour with characteristic translocation SS18-SSX1/2/rarely 4 fusion transcripts, and presents most often in adolescents and young adults. According to the World Health Organization (WHO) classification, synovial sarcoma is a malignant tumour of uncertain differentiation.

AIMS

To present a case series of PPSS with clinical, pathological and molecular analysis at a rare primary site.

SETTING AND DESIGN

Retrospective study conducted in a tertiary care hospital.

MATERIALS AND METHODS

Twenty-two cases of PPSSs were retrieved from electronic database between January 2009 to December 2018. Metastatic tumours from soft tissue primaries were excluded. Immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR) were performed. Statistical analysis was performed using Mann-Whitney non-parametric test.

RESULTS

Among 22 patients, the male-female ratio was 3.4:1 and the median age was 31.5 years. The tumours were classified as monophasic (90.9%) and biphasic (9.1%) subtypes and graded as grade 2(77.3%) and grade 3(22.7%). IHC demonstrated expression of TLE1 (17/17 cases), Bcl-2 (7/8 cases), focal EMA (16/17 cases), CD99 (10/11 cases), focal pancytokeratin (8/12 cases) and CD56 (14/14 cases). The fusion transcripts included SYT-SSX1(4/11, 36.4%) and SYT-SSX2 (2/11, 18.2%). The remaining five cases were negative for SS18 rearrangement by RT-PCR. Only 8 patients had localised tumour. Surgical excision was performed in 5 patients. The median follow-up period was 6 months and 21 days.

CONCLUSIONS

Monophasic SS was the most common subtype. Small core biopsies pose a diagnostic challenge, in such a scenario, a combination of clinical, histomorphological, immunomarkers and genetic studies help confirm the diagnosis of PPSS.

Pathological response and clinical outcomes in operable triple-negative breast cancer with cisplatin added to standard neoadjuvant chemotherapy

BACKGROUND

Response to neoadjuvant chemotherapy is associated with improved outcomes for patients with triple negative breast cancer (TNBC). Patients with residual disease are at increased risk of relapse and death from breast cancer. In this retrospective study, we aimed to evaluate the efficacy and safety of cisplatin added to standard neoadjuvant chemotherapy for locally advanced TNBC.

MATERIALS AND METHODS

All TNBC treated with neoadjuvant cisplatin 60mg/m2 once in 3 weeks with weekly paclitaxel for 12 weeks, following 8 weeks of dose-dense epirubicin 90mg/m2 or doxorubicin 60mg/m2 with cyclophosphamide 600mg/m2 were analyzed retrospectively. The data related to pathological complete response, adherence to planned therapy, disease-free survival and overall survival were collected.

RESULTS

Eighty-three patients were included, of whom 80% had stage III disease. Pathological complete response in both breast (T0/Tis) and axilla (N0) was observed in 48.1% of patients. Miller Payne grade 5 pathological response in the breast was seen in 61% of patients. Good partial responses (Miller Payne grades 3,4) were observed in 32.5% of patients. The remaining 6.5% were poor responders. Seventy-seven patients underwent surgery. The disease-free survival at 1 and 3 years for those who had a pathological complete response was 96.7% and 77.6%, respectively, and 92.3% and 62.7% for those who did not, respectively. The predominant adverse events were hematological, with anemia being the most common one.

CONCLUSION

The addition of cisplatin to neoadjuvant chemotherapy with anthracycline and taxane in TNBC was tolerable and produced a high rate of pathological complete response. Cisplatin added to standard chemotherapy in patients with locally advanced TNBC could improve clinical outcomes.