A nationwide study of breast reconstruction after mastectomy in patients with breast cancer receiving postmastectomy radiotherapy: comparison of complications according to radiotherapy fractionation and reconstruction procedures.

BACKGROUND: We examined the patterns of breast reconstruction postmastectomy in breast cancer patients undergoing postmastectomy radiotherapy (PMRT) and compared complications based on radiotherapy fractionation and reconstruction procedures. METHODS: Using National Health Insurance Service (NHIS) data (2015-2020), we analysed 4669 breast cancer patients with PMRT and reconstruction. Using propensity matching, cohorts for hypofractionated fractionation (HF) and conventional fractionation (CF) were created, adjusting for relevant factors and identifying grade ≥3 complications. RESULT: Of 4,669 patients, 30.6% underwent HF and 69.4% CF. The use of HF has increased from 19.4% in 2015 to 41.0% in 2020. Immediate autologous (32.9%) and delayed two-stage implant reconstruction (33.9%) were common. Complication rates for immediate (N = 1286) and delayed two-stage (N = 784) reconstruction were similar between HF and CF groups (5.1% vs. 5.4%, P = 0.803, and 10.5% vs. 10.7%, P = 0.856, respectively) with median follow-ups of 2.5 and 2.6 years. HF showed no increased risk of complications across reconstruction methods. CONCLUSION: A nationwide cohort study revealed no significant difference in complication rates between the HF and CF groups, indicating HF for reconstructed breasts is comparable to CF. However, consultation regarding the fractionation for reconstructed breast cancer patients may still be necessary.

Role of prognostic nutritional index in postoperative radiotherapy for non-small cell lung cancer.

BACKGROUND: The prognostic nutritional index (PNI) is known to be correlated with clinical outcomes in non-small cell lung cancer (NSCLC) patients. However, its role has not been studied in patients who have undergone postoperative radiotherapy (PORT). This study aimed to investigate the relationship between PNI and survival and recurrence in NSCLC patients with PORT. METHODS: We reviewed 97 stage I-III NSCLC patients who received PORT between January 2006 and December 2016 at our institution. We obtained PNI values for both pre-RT (within 1 month before PORT) and post-RT (within 2 months after PORT) by using serum albumin and lymphocyte count. A cutoff value for PNI was determined by the receiver operating characteristic curve (ROC). The median follow-up period was 52.8 months. RESULTS: The ROC curve of post-RT PNI exhibited a higher area under the curve (AUC 0.68, cut-off: 47.1) than that of pre-RT PNI (AUC 0.55, cutoff: 50.3), so the group was divided into high post-RT PNI (> 47.1) and low post-RT PNI ( ≤ 47.1). The five-year overall survival rate (OS) was 66.2% in the high post-RT group, compared with 41.8% in the low post-RT PNI group (p = 0.018). Those with both low pre-RT and low post-RT PNI had the worst five-year OS of 31.1%. Post-RT PNI (HR 0.92, p = 0.003) was an independent risk factor for mortality. CONCLUSIONS: PNI after PORT was significantly associated with survival. This finding suggests that PNI can be used as a prognostic marker.

Development and benchmarking of a Korean audio speech recognition model for Clinician-Patient conversations in radiation oncology clinics.

BACKGROUND: The purpose of this study is to develop an audio speech recognition (ASR) deep learning model for transcribing clinician-patient conversations in radiation oncology clinics. METHODS: We finetuned the pre-trained English QuartzNet 15x5 model for the Korean language using a publicly available dataset of simulated situations between clinicians and patients. Subsequently, real conversations between a radiation oncologist and 115 patients in actual clinics were then prospectively collected, transcribed, and divided into training (30.26 h) and testing (0.79 h) sets. These datasets were used to develop the ASR model for clinics, which was benchmarked against other ASR models, including the 'Whisper large,' the 'Riva Citrinet-1024 Korean model,' and the 'Riva Conformer Korean model.' RESULTS: The pre-trained English ASR model was successfully fine-tuned and converted to recognize the Korean language, resulting in a character error rate (CER) of 0.17. However, we found that this performance was not sustained on the real conversation dataset. To address this, we further fine-tuned the model, resulting in an improved CER of 0.26. Other developed ASR models, including 'Whisper large,' the 'Riva Citrinet-1024 Korean model,' and the 'Riva Conformer Korean model.', showed a CER of 0.31, 0.28, and 0.25, respectively. On the general Korean conversation dataset, 'zeroth-korean,' our model showed a CER of 0.44, while the 'Whisper large,' the 'Riva Citrinet-1024 Korean model,' and the 'Riva Conformer Korean model' resulted in CERs of 0.26, 0.98, and 0.99, respectively. CONCLUSION: In conclusion, we developed a Korean ASR model to transcribe real conversations between a radiation oncologist and patients. The performance of the model was deemed acceptable for both specific and general purposes, compared to other models. We anticipate that this model will reduce the time required for clinicians to document the patient's chief complaints or side effects.

Excluding prepontine cistern from whole ventricle radiotherapy target volume in localized germinoma.

PURPOSE: The target delineation of whole ventricle radiotherapy (WVRT) in germinoma varies among radiation oncologists, especially regarding the inclusion of the prepontine cistern (PC). We evaluated the outcome of PC-sparing WVRT in localized germinoma. MATERIALS AND METHODS: We identified 87 localized intracranial germinoma patients who received radiotherapy (RT) following chemotherapy between 1999 and 2020. By institutional policy, RT for localized germinoma excluded PC from the target volume. WVRT was delivered to 65 patients (74.7%) and involved field radiotherapy (IFRT) to 22 patients (25.3%). The median dose was 45.0 Gy (range, 23.4 to 55.8 Gy) for the primary tumor and 19.8 Gy (rangem 14.4 to 36.0 Gy) for the whole ventricle. We analyzed the dosimetric differences of the organs at risk between the PC-excluding plans and the PC-including ones. RESULTS: The median follow-up duration was 7.8 years (range, 1.0 to 22.5 years). The 10-year recurrence-free survival and overall survival rates were 86.3% and 90.9%, respectively. The recurrences occurred in eight patients (8.7%), including five patients after IFRT and three after WVRT. Five of them showed recurrences at lateral ventricles and only one patient experienced spinal cord relapse. However, no relapse in the PC occurred. Endoscopic third ventriculostomy was not a significant prognostic factor. The dosimetric comparisons showed significantly lower mean doses to the brainstem and the cochleae when the PC was excluded. CONCLUSION: WVRT for localized germinoma can safely exclude the PC in the target volume, reducing radiation dose to the brain stem. The target protocol needs to reach a consensus regarding the PC in prospective trials.

Effect of postoperative radiotherapy for patients with differentiated thyroid cancer.

OBJECTIVE: We evaluated the efficacy and safety of postoperative radiotherapy (PORT) for differentiated thyroid cancer (DTC) with high risk features. MATERIALS AND METHODS: This retrospective study analyzed 187 patients treated for DTC from 1985 to 2019. DTC referred to nonanaplastic thyroid cancer originating from follicular cells. PORT was defined as the administration of external beam radiation to the thyroid and regional lymph nodes following surgery for initially diagnosed DTC. The patients were included in the analysis if they received PORT or exhibited any of the following features: (a) pT4 or pN1b according to the 8th American Joint Committee on Cancer, (b) poorly differentiated thyroid cancer (PDTC), or (c) unfavourable variants such as anaplastic foci and etc. After 1:1 propensity matching, a total of 108 patients were analyzed according to PORT receipt. The median follow-up duration of the matched group was 10.4 years. RESULTS: After matching, most of the variables became balanced, but the PORT group still had more PDTC and DTC with anaplastic foci. Radioactive iodine (RAI) was less frequently administered in the PORT group. PORT yielded a significantly higher 5-year locoregional recurrence free survival (LRFS) than the No PORT group (5-year LRFS 86.1% vs. 72.7%, p = 0.022), but the 10-year cancer specific survival (CSS) was similar between them (97.8% vs. 85.9%, p = 0.122). The multivariable analysis indicated that PORT was a favourable prognostic factor (Hazard ratio 0.3, 95% Confidence interval 0.1-0.8, p = 0.02) for LRFS, but not for CSS. Among 133 patients without PORT for initial disease, 39 of them received salvage surgery followed by salvage PORT. No severe toxicity after PORT was reported. CONCLUSION: PORT reduced locoregional recurrence in DTC patients without severe toxicity. PORT can be an effective and safe treatment to improve locoregional control in DTC with high risk features. However, further study is warranted to identify those who can benefit from PORT.