Trends and distribution of external radiation therapy facilities in Japan based on Survey of Medical Institutions from the Ministry of Health, Labour and Welfare.

This study aimed to explore the distribution of external radiation therapy (RT) facilities, the status of related device installations and the adoption of high-precision RT using Survey of Medical Institutions from the Ministry of Health, Labour and Welfare in Japan. Analysis, categorized by the hospital size and prefecture, provides specific insights into the trends in treatment facility healthcare capabilities. Data on the number of RT facilities, high-precision RT facilities, RT devices and treatment planning systems (TPS) categorized by the number of beds and prefecture from 1996 to 2020 were analyzed. In addition, the study examined the correlation between the high-precision implementation rate and the number of TPSs or radiation oncologists and other medical staff. High-precision RT exceeded 95% in large facilities (800+ beds) but remained <50% in medium-sized facilities (300-499 beds). In a prefecture-by-prefecture analysis, calculation of the maximum-minimum ratio of RT facilities per million population and per 30 km2 revealed a disparity of 3.7 and 73.1 times in the population ratio and the density ratio, respectively. Although a correlation was found between the number of TPSs per RT device or the number of medical physicists per million population and the rate of high-precision RT implementation, no correlation was found among other professions. Detailed analysis based on the hospital size and prefecture provided more specific information on the medical functions of RT facilities in Japan. These findings can potentially contribute to the future development of RT, including the standardization of treatment techniques and optimal resource allocation.

Impact of concurrent antibody-drug conjugates and radiotherapy on symptomatic radiation necrosis in breast cancer patients with brain metastases: a multicenter retrospective study.

AIM: We aimed to investigate the impact of concurrent antibody-drug conjugates (ADC) and radiotherapy on symptomatic radiation necrosis (SRN) in breast cancer patients with brain metastases (BM). METHODS: This multicenter retrospective study uses four institutional data. Eligibility criteria were histologically proven breast cancer, diagnosed BM with gadolinium-enhanced MRI, a Karnofsky performance status of 60 or higher, and radiotherapy for all BM lesions between 2017 and 2022. Patients with leptomeningeal dissemination were excluded. Concurrent ADC was defined as using ADC within four weeks before or after radiotherapy. The cumulative incidence of SRN until December 2023 with death as a competing event was compared between the groups with and without concurrent ADC. Multivariable analysis was performed using the Fine-Gray model. RESULTS: Among the 168 patients enrolled, 48 (29%) received ADC, and 19 (11%) had concurrent ADC. Of all, 36% were HER2-positive, 62% had symptomatic BM, and 33% had previous BM radiation histories. In a median follow-up of 31 months, 18 SRNs (11%) were registered (11 in grade 2 and 7 in grade 3). The groups with and without concurrent ADC had 5 SRNs in 19 patients and 13 SRNs in 149, and the two-year cumulative incidence of SRN was 27% vs. 7% (P = 0.014). Concurrent ADC was associated with a higher risk of SRN on multivariable analysis (subdistribution hazard ratio, 3.0 [95% confidence interval: 1.1-8.3], P = 0.030). CONCLUSIONS: This study suggests that concurrent ADC and radiotherapy are associated with a higher risk of SRN in HER2-positive breast cancer patients.

Classification of Patients With Painful Tumors to Predict Response to Palliative Radiation Therapy.

PURPOSE: This study aimed to identify factors affecting pain response to develop a patient classification system for palliative radiation therapy (RT). METHODS AND MATERIALS: Our prospective observational study (UMIN000044984) provided data on patients who received palliative RT for painful tumors. The eligibility criteria were having a numerical rating scale (NRS) score of 2 or more before treatment and receiving palliative RT between August 2021 and September 2022. Post-RT follow-up was scheduled prospectively at 2, 4, 12, 24, 36, and 52 weeks. Pain response was assessed using the International Consensus Pain Response Endpoints criteria, with the primary outcome being the response rate within 12 weeks. Multivariable logistic regression was performed to identify factors affecting pain response and develop the classification system. Each class evaluated the differences in response rate, time to response, and progression. RESULTS: Of the 488 registered lesions, 366 from 261 patients met the criteria. Most patients had bone metastases (75%), of whom 72% were using opioids and 22% underwent reirradiation. Conventional RT (eg, 8-Gy single fraction, 20 Gy in 5 fractions) was administered to 93% of patients. Over a median of 6.8 months of follow-up, the average NRS decreased from 6.1 to 3.4 at 12 weeks for 273 evaluable lesions, with a 60% response rate. Opioid use and reirradiation negatively affected the response rate in multivariate analysis (P < .01). Lesions were categorized into class 1 (no opioid use and no reirradiation; 89 lesions), class 2 (neither class 1 nor 3; 211 lesions), and class 3 (opioid use and reirradiation; 66 lesions), with respective response rates of 75%, 61%, and 36% (P < .001). Time to response was similar across the classes (P = .91), but the progression rates at 24 weeks differed (11%, 27%, and 63%, respectively; P < .001). CONCLUSIONS: Opioid use and reirradiation are factors leading to significant variations in pain response rates and time to progression.

Re-irradiation spine stereotactic body radiotherapy following high-dose conventional radiotherapy for metastatic epidural spinal cord compression: a retrospective study.

PURPOSE:  We aimed to evaluate the efficacy and safety of re-irradiation stereotactic body radiation therapy (SBRT) in patients with metastatic epidural spinal cord compression (MESCC) following high-dose conventional radiotherapy. MATERIALS AND METHODS:  Twenty-one patients met the following eligibility criteria: with an irradiation history of 50 Gy2 equivalent dose in 2-Gy fractions (EQD2) or more, diagnosed MESCC in the cervical or thoracic spines, and treated with re-irradiation SBRT of 24 Gy in 2 fractions between April 2018 and March 2023. Prior treatment was radiotherapy alone, not including surgery. The primary endpoint was a 1-year local failure rate. Overall survival (OS) and treatment-related adverse events were assessed as the secondary endpoints. Since our cohort includes one treatment-related death (TRD) of esophageal perforation, the cumulative esophageal dose was evaluated to find the dose constraints related to severe toxicities. RESULTS:  The median age was 68, and 14 males were included. The primary tumor sites (esophagus/lung/head and neck/others) were 6/6/7/2, and the median initial radiotherapy dose was 60 Gy2 EQD2 (range: 50-105 Gy2, 60-70/ > 70 Gy2 were 11/4). Ten patients underwent surgery followed by SBRT and 11 SBRT alone. At the median follow-up time of 10.4 months, 17 patients died of systemic disease progression including one TRD. No radiation-induced myelopathy or nerve root injuries occurred. Local failure occurred in six patients, with a 1-year local failure rate of 29.3% and a 1-year OS of 55.0%. Other toxicities included five cases of vertebral compression fractures (23.8%) and one radiation pneumonitis. The cumulative esophageal dose was recommended as follows: Dmax < 203, D0.035 cc < 187, and D1cc < 167 (Gy3 in biological effective dose). CONCLUSION:  Re-irradiation spine SBRT may be effective for selected patients with cervical or thoracic MESCC, even with high-dose irradiation histories. The cumulative dose assessment across the original and re-irradiated esophagus was recommended to decrease the risk of severe esophageal toxicities.

Safety and Efficacy of Gemcitabine Plus Cisplatin Against Recurrent/Metastatic Nasopharyngeal Carcinoma: A Retrospective Study.

BACKGROUND/AIM: Although gemcitabine plus cisplatin (GC) prolongs survival in patients with recurrent or metastatic nasopharyngeal carcinoma (R/M NPC) compared with fluorouracil plus cisplatin, no study has evaluated the efficacy and safety of GC in nonendemic regions, including Japan, yet. Therefore, we assessed the safety and efficacy of GC in Japanese patients with R/M NPC. PATIENTS AND METHODS: We retrospectively reviewed patients with R/M NPC who received GC treatment at the Aichi Cancer Center Hospital from January 2017 to March 2020. The main eligibility criteria were histologically confirmed NPC, Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-2, and locally recurrent disease unsuitable for local treatment or metastatic disease. The regimen was administered every 3 weeks (gemcitabine, 1,000 mg/m2 on days 1 and 8; cisplatin, 80 mg/m2 on day 1). RESULTS: Fourteen patients (median age, 58 years) were included in the study. Two patients had an ECOG PS of 2 and 11 exhibited nonkeratinizing histology. Of the eight patients with measurable lesions, one exhibited complete response and seven exhibited partial response, with an objective response rate of 75%. Median progression-free survival and overall survival were 7.7 and 24.2 months, respectively. Common grade 3 or 4 adverse events included neutropenia (64%), thrombocytopenia (14%), and febrile neutropenia (14%). The median relative dose intensity of gemcitabine and cisplatin was 62% and 60%, respectively. No treatment-related deaths occurred. CONCLUSION: The GC regimen demonstrates promising activity and is tolerable in Japanese patients with R/M NPC.

Palliative radiotherapy for painful non-bone lesions in patients with advanced cancer: a single center retrospective study.

PURPOSE: This retrospective study aimed to assess the efficacy and safety of palliative radiotherapy for painful non-bone lesions in patients with advanced cancer. MATERIALS AND METHODS: We enrolled patients with painful non-bone lesions who underwent conventional palliative radiotherapy between September 2018 and September 2022. The treatment targets included primary tumor lesions, lymph node metastases, non-bone hematogenous metastases, and other lesions. The primary endpoint was the overall pain response rate in evaluable patients, determined based on the International Consensus Pain Response Endpoint criteria. The secondary endpoints included overall survival, pain recurrence, and adverse events. RESULTS: Of the 420 screened patients, 142 received palliative radiotherapy for painful non-bone lesions, and 112 were evaluable. A pain response was achieved in 67 patients (60%) of the 112 evaluable patients within a median of 1.2 months. Among these patients, 25 exhibited complete response, 42 partial response, 18 indeterminate response, and 27 pain progression. The median survival time was 5.5 months, recorded at a median follow-up of 6.0 months, during which 67 patients died. Multivariate analysis identified poor performance status scores of 2-4, opioid use, and re-irradiation as independent factors associated with a reduced likelihood of achieving a pain response. Pain recurrence occurred in 18 patients over a median of 4.1 months. Seventeen patients had grade 1-2 adverse events, while none experienced grade 3 or higher toxicity. CONCLUSION: Palliative radiotherapy can potentially be a safe and well-tolerated modality for managing painful non-bone lesions, with a low rate of adverse events.

Dose-Finding and Efficacy Confirmation Trial of the Superselective Intra-arterial Infusion of Cisplatin and Concomitant Radiation Therapy for Locally Advanced Maxillary Sinus Cancer (JCOG1212): Results of the Efficacy Confirmation Phase in Patients with T4aN0M0.

PURPOSE: Locally advanced maxillary sinus cancers require radical surgery as a standard treatment, but this often results in significant disfigurement and impairment of function. JCOG1212 seeks to evaluate the safety and efficacy of the superselective intra-arterial infusion of cisplatin and concomitant radiation therapy (RADPLAT) for T4aN0M0 and T4bN0M0 maxillary sinus squamous cell carcinomas. We herein report the results of the efficacy confirmation phase in the T4a cohort. METHODS AND MATERIALS: Patients received 100 mg/m2 cisplatin intra-arterially weekly for 7 weeks with concomitant radiation therapy (total 70 Gy) as determined by the results of the preceding dose-finding phase. The trial aimed to evaluate the primary endpoint of 3-year overall survival (OS), comparing RADPLAT with the historical control for 3-year OS in surgery (80%). RESULTS: From April 2014 to August 2018, 65 patients were registered in the T4a cohort from 18 institutions, consisting of 54 men and 11 women with a median age of 64 years (range, 40-78 years) and Eastern Cooperative Oncology Group performance status 0/1 (58/7). After excluding 1 ineligible patient, 64 patients were included in the primary analysis of efficacy and safety. The median follow-up was 4.5 years in all eligible patients, and the primary endpoint for 3-year OS was 82.8% (90% CI, 73.4%-89.2%). With regard to acute adverse events, mucositis (grade ≥3), neutropenia (grade ≥3), increased creatinine (grade ≥2), hearing impairment (grade ≥2), and stroke (grade ≥2) were observed in 20.3%, 14.1%, 3.1%, 3.1%, and 1.6% of patients, respectively. One treatment-related death due to a thromboembolic event was reported. CONCLUSIONS: We demonstrated that RADPLAT showed favorable results for patients with T4aN0M0 maxillary sinus squamous cell carcinomas compared with the historical control for 3-year OS in surgery, which was from an earlier period, and showed some specific toxicities. Therefore, RADPLAT, as well as surgery, can be regarded as a possible treatment option for these patients.

Changing trends in gamma knife surgery to linear accelerator brain stereotactic radiotherapy in Japan: a survey based on the nationwide claims database.

PURPOSE: This study evaluated the trends in the platform for stereotactic radiotherapy to the brain (SRT), utilizing the open data of the National Database published by the Ministry of Health, Labour, and Welfare. MATERIALS AND METHODS: This study analyzed data from FY2014 to FY2021. The practices included in the study were gamma knife surgery (GKS) and SRT with a linear accelerator (LINAC). The total number of outpatient and inpatient cases in each SRT system was evaluated annually. RESULTS: From April 2014 to March 2022, the study included 212,016 cases (102,691 GKS and 109,325 LINAC) of the registered 1,996,540 radiotherapy cases. In the first year, 13,117 (54.1%) cases were GKS, and 11,128 (45.9%) were LINAC; after that, GKS decreased, and LINAC increased, reaching the same rate in FY2017. Compared to the first year, the final year showed 11,702 GKS (- 1415 or - 10.8%) and 17,169 LINAC (+ 6041 or + 54.3%), with an increase of 4626 total SRT cases to 28,871 (+ 19.1%). The percentage of outpatient treatment also increased from 4.6 to 11.8% for GKS and from 44.7 to 57.9% for LINAC. CONCLUSION: The study found a gradual decrease in the selection of GKS, an increasing trend in the selection of LINAC, and an increase in the overall number of stereotactic irradiations. In particular, the proportion of outpatient treatment increased, indicating that more than half of LINAC was selected for outpatient treatment.

Peptide Receptor Radionuclide Therapy for Recurrent Olfactory Neuroblastoma After Cranioplasty for Surgical Infection: A Case Report.

BACKGROUND: Peputide receptor radionuclide therapy with 177Lu for midgut neuroendocrine metastasis has been clinically approved as a safe treatment. Unresectable metastases of olfactory neuroblastoma have shorter survival due to insufficient effective systemic treatment. CASE REPORT: Herein, we report a patient treated with peputide receptor radionuclide therapy for unresectable recurrent olfactory neusroblastoma following a rare cranial metastasectomy infection. A 50-year-old female patient with olfactory neuroblastoma of Kadish C was initially treated by skull base surgery plus postoperative radiotherapy following chemotherapy. Recurrent disease with neck and intracranial metastases was treated by four salvage surgeries. Surgical site infection following intracranial metastasectomy was treated with debridement and delayed cranioplasty. Peputide receptor radionuclide therapy was performed for unresectable multiple metastases after cranioplasty. Successful therapy using four cycles of peputide receptor radionuclide had neither grade 3 nor grade 4 adverse events. The patient was followed at an outpatient clinic. CONCLUSION: Further case accrual of peputide receptor radionuclide therapy is required to develop a treatment for unresectable olfactory neuroblastoma.

Clinical Efficacy and Openness to New Challenges of Low Dose Rate Brachytherapy for Prostate Cancer.

Over a century ago, low-dose-rate (LDR) brachytherapy was introduced to treat prostate cancer (PCa). Since then, it has been widely applied worldwide, including in East Asia. LDR brachytherapy has been performed in 88 institutes in Japan. Beneficial clinical outcomes of LDR brachytherapy for intermediate-to-high-risk PCa have been demonstrated in large clinical trials. These clinical outcomes were achieved through advances in methods, such as urological precise needle puncture and seed placement, and the quantitative decision making regarding radiological parameters by radiation oncologists. The combined use of LDR brachytherapy with other therapeutic modalities, such as external beam radiation and androgen deprivation therapy, for the clinical risk classification of PCa has led to better anticancer treatment efficacy. In this study, we summarized basic LDR brachytherapy findings that should remain unchanged and be passed down in urology departments. We also discussed the applications of LDR brachytherapy for PCa in various clinical settings, including focal and salvage therapies. In addition, we highlighted technologies associated with brachytherapy that are under development.

Estimation of the risk of secondary cancer in rectum and bladder after radiation therapy for prostate cancer using a feasibility dose-volume histogram.

We investigated the risk of secondary cancers in rectum and bladder for prostate cancer radiotherapy using a feasibility assessment tool. We calculated the risk of secondary cancer by generating a dose-volume histogram based on an ideal dose falloff function (f-value). This study found a smaller f-value was associated with a lower secondary cancer risk in the rectum but a higher risk in the bladder. The study suggests setting the f-value at 0-0.1 as the optimization goal for the rectum and 0.4 for the bladder is reasonable and feasible for reducing the risk of secondary cancer and other adverse events.

Retrospective non-inferiority study of stereotactic radiosurgery for more than ten brain metastases.

AIM: This study aimed to investigate the clinical benefits of stereotactic radiosurgery (SRS) in patients with > 10 brain metastases (BM) compared to patients with 2-10 BM. METHODS: The study included multiple BM patients who underwent SRS between 2014 and 2022, excluding patients who underwent whole brain radiotherapy, had a Karnofsky Performance Status score < 60, suspected leptomeningeal disease, or a single BM lesion. Patients were divided into two groups (2-10 and > 10 BM groups) and matched 2:1 based on propensity scores. The primary endpoint was overall survival (OS) in the matched dataset, with intracranial progression-free survival (PFS) as the secondary endpoint. Non-inferiority was established if the upper limit of the 95% confidence interval (CI) of the adjusted hazard ratio was below 1.3. RESULTS: Of the 1042 patients identified, 434 met eligibility criteria. After propensity score matching, 240 patients were analyzed (160 in the BM 2-10 group and 80 in the > 10 BM group). The median OS was 18.2 months in the 2-10 BM group and 19.4 months in the > 10 BM group (P = 0.60). The adjusted hazard ratio was 0.86 (95% CI: 0.59-1.24), indicating non-inferiority. PFS was not significantly different between the groups (4.8 months vs. 4.8 months, P = 0.94). The number of BM did not significantly impact OS or PFS. CONCLUSIONS: SRS for selected patients with > 10 BM was non-inferior in terms of OS compared to those with 2-10 BM in a propensity score-matched dataset.

Brentuximab vedotin plus AVD followed by involved-node radiotherapy in a patient with classic Hodgkin lymphoma following gray zone lymphoma after autologous stem-cell transplantation failure.

BACKGROUND: No consensus has been reached yet concerning treatment strategies for a sequential classic Hodgkin lymphoma (CHL) following gray zone lymphoma (GZL). Prognosis of GZL after a failed autologous hematopoietic stem-cell transplantation (auto-HCT) is poor and treatment strategy is very limited. As yet there are limited data showing clinical outcomes of brentuximab vedotin (BV) for GZL, especially for sequential CHL after GZL. CASE PRESENTATION: We report a case of CHL following primary refractory GZL after a failed auto-HCT and showed favorable response to first-line CHL-directed chemoradiotherapy consisting of BV plus doxorubicin, vinblastine, and dacarbazin (AVD) followed by irradiation. The sequential cases with an early evolution, whose diagnosis of second lymphoma was made within a year, have been recently reported very poor survival shorter than a year. Whether a sequential CHL following GZL should be treated as a primary or relapsed disease has not been clearly elucidated. Our patient showed favorable response to first-line CHL-directed chemoradiotherapy without allogenic hematopoietic stem-cell transplantation and has in continuous remission for 2 years. CONCLUSIONS: The management of our case could help for physicians to make better treatment decisions and provide insights for further exploration in future studies.

Dosimetric analysis on computed tomography myelography based treatment planning in stereotactic body radiotherapy for spinal metastases.

This study aimed to quantitatively evaluate the influence of enhanced contrast on the CT myelography image of the spinal cord and/or cauda equina in addition to the target volume in spine SBRT treatment planning. In total, 19 patients who had previously undergone spine SBRT were randomly selected. The rigid image registration accuracy of CT myelography that aligned with the treatment planning CT was evaluated by calculating the normalized mutual information (NMI) and Pearson's correlation coefficient for the vertebral landmarks. At postregistration, the contrast-enhanced region of the CT myelography image was replaced with water-mass density, and the original treatment plan was recalculated on this image. For comparison, the dose was also recalculated on the contrast-enhanced CT myelography images. The NMI and Pearson's correlation coefficients for landmarks were 0.39 ± 0.12 and 0.97 ± 0.04, respectively. The mean D0.035cc of the spinal cord and/or cauda equina on the CT myelography image with the contrast-enhanced region replaced by water-mass density showed -0.37% ± 0.64% changes compared with that of the treatment planning CT. Conversely, the mean D0.035cc in contrast-enhanced CT myelography changed by -1.39% ± 0.51%. The percentage change in D98% for the planning target volume was confirmed to be small by replacing the contrast-enhanced region with water-mass density (p < 0.01). The dose calculation of the target volume, spinal cord, and/or cauda equina using the CT myelography image that replaced the contrast-enhanced region with water-mass density could be a more appropriate procedure with less dose calculation uncertainty.

Recent trends of characteristics and treatments in adults with newly diagnosed brain metastases.

OBJECTIVE: We aimed to evaluate recent trends in characteristics and treatments among patients with brain metastases in clinical practice. METHODS: All newly diagnosed patients with brain metastases during 2016-2021 at a single cancer center were enrolled. We collected the detailed features of each patient and estimated the number of candidates considered to meet the following criteria used in common clinical trials: Karnofsky performance status ≥ 70 and mutated non-small cell lung cancer, breast cancer or melanoma. The brain metastases treatments were classified as follows: (i) stereotactic radiosurgery, (ii) stereotactic radiosurgery and systemic therapy, (iii) whole-brain radiotherapy, (iv) whole-brain radiotherapy and systemic therapy, (v) surgery, (vi) immune checkpoint inhibitor or targeted therapy, (vii) cytotoxic agents and (ix) palliative care. Overall survival and intracranial progression-free survival were estimated from brain metastases diagnosis to death or intracranial progression. RESULTS: A total of 800 brain metastases patients were analyzed; 597 (74.6%) underwent radiotherapy, and 422 (52.7%) underwent systemic therapy. In addition, 250 (31.3%) patients were considered candidates for common clinical trials. Compared to 2016, the later years tended to shift from whole-brain radiotherapy to stereotactic radiosurgery (whole-brain radiotherapy: 35.7-29.1% and stereotactic radiosurgery: 33.4-42.8%) and from cytotoxic agents to immune checkpoint inhibitor/targeted therapy (cytotoxic agents: 10.1-5.0 and immune checkpoint inhibitor/targeted therapy: 7.8-10.9%). There was also an increase in the proportion of systemic therapy combined with radiation therapy (from 26.4 to 36.5%). The median overall survival and progression-free survival were 12.7 and 5.3 months, respectively. CONCLUSIONS: This study revealed the diversity of brain metastases patient characteristics, recent changes in treatment selection and the percentage of candidates in clinical trials.

Radiotherapy or systemic therapy versus combined therapy in patients with brain metastases: a propensity-score matched study.

AIM: This study aimed to evaluate the clinical benefits of systemic therapy (ST) combined with stereotactic radiosurgery (SRS) for brain metastases (BM). METHODS: The patient data were extracted from the institutional disease database from 2016 to 2021. Surgical and whole-brain radiotherapy cases and poor Karnofsky performance status (KPS < 70) were excluded. The eligible patients were divided into monotherapy (SRS alone or ST alone) and combined therapy (SRS and ST, combined within a month). Univariate and multivariate Cox proportional hazards analyses were used to examine factors associated with increased risk of death and intracranial progression. The propensity score for selecting treatment was calculated based on existing prognostic covariates. Two groups were matched 1:1 and compared for intracranial progression-free survival (PFS) and overall survival (OS). RESULTS: We identified 1605 patients and analyzed 928 (monotherapy: n = 494, combined therapy: n = 434). In a multivariable model, the combined therapy was independently associated with improved PFS and OS relative to the monotherapy. At the median follow-up of 383 days in the matched dataset, the combined therapy group showed significantly longer PFS (median, 7.4 vs. 5.0 months, P < 0.001) and OS (median, 23.1 vs. 17.2 months, P = 0.036) than the monotherapy group. The overall intracranial progression and mortality risk was reduced in the combined therapy group, with an estimated HR of 0.70 and 0.78. CONCLUSIONS: Combined therapy exhibited longer PFS and OS than monotherapy in BM patients. The results support the recent trend toward combining systemic and local therapies, encouraging future clinical trials.

Development of deep learning chest X-ray model for cardiac dose prediction in left-sided breast cancer radiotherapy.

Deep inspiration breath-hold (DIBH) is widely used to reduce the cardiac dose in left-sided breast cancer radiotherapy. This study aimed to develop a deep learning chest X-ray model for cardiac dose prediction to select patients with a potentially high risk of cardiac irradiation and need for DIBH radiotherapy. We used 103 pairs of anteroposterior and lateral chest X-ray data of left-sided breast cancer patients (training cohort: n = 59, validation cohort: n = 19, test cohort: n = 25). All patients underwent breast-conserving surgery followed by DIBH radiotherapy: the treatment plan consisted of three-dimensional, two opposing tangential radiation fields. The prescription dose of the planning target volume was 42.56 Gy in 16 fractions. A convolutional neural network-based regression model was developed to predict the mean heart dose (∆MHD) reduction between free-breathing (MHDFB) and DIBH. The model performance is evaluated as a binary classifier by setting the cutoff value of ∆MHD > 1 Gy. The patient characteristics were as follows: the median (IQR) age was 52 (47-61) years, MHDFB was 1.75 (1.14-2.47) Gy, and ∆MHD was 1.00 (0.52-1.64) Gy. The classification performance of the developed model showed a sensitivity of 85.7%, specificity of 90.9%, a positive predictive value of 92.3%, a negative predictive value of 83.3%, and a diagnostic accuracy of 88.0%. The AUC value of the ROC curve was 0.864. The proposed model could predict ∆MHD in breast radiotherapy, suggesting the potential of a classifier in which patients are more desirable for DIBH.

Successful IMRT and concurrent chemotherapy for a patient with intrathoracic extensive-stage small cell lung cancer.

Treatment of extensive-stage (ES) small cell lung cancer (SCLC) is a challenge with poor local control and dismal overall survival. Although single extrathoracic metastasis was defined as M1b according to the eighth edition of the tumour-node-metastasis (TNM) classification of lung cancer, M1b includes involvement of a single intrathoracic nonregional lymph node (LN) such as pericardial, internal mammary or paravertebral LNs. Here, we report a successful treated case of a 50-year-old female with ES-SCLC with right pericardial LN involvement, cT1cN3M1b (LYM). She initially received two cycles of induction chemotherapy consisting of cis-Diamminedichloroplatinum/cisplatin (CDDP) and etoposide and achieved a very good partial response. She then received curative chemoradiotherapy with intensity-modulated techniques (45 Gy in 30 fractions BID), followed by an additional cycle of chemotherapy. She is free of recurrence for more than 2.5 years.

Preoperative spirometry and BMI in deep inspiration breath-hold radiotherapy: the early detection of cardiac and lung dose predictors without radiation exposure.

BACKGROUND: This study aimed to investigate preoperative spirometry and BMI as early predictors of the mean heart and lung dose (MHD, MLD) in deep inspiration breath-hold (DIBH) radiotherapy. METHODS: Left-sided breast cancer patients underwent breast-conserving surgery followed by DIBH radiotherapy enrolled. Patients who were not available for preoperative spirometry were excluded. One hundred eligible patients were performed free-breathing (FB-) CT and DIBH-CT for plan comparison. We completed the correlative and multivariate analysis to develop the linear regression models for dose prediction. The residuals were calculated to explore the unpreferable subgroups and compare the prediction accuracy. RESULTS: Among the parameters, vital capacity (VC) and BMI showed the strongest negative correlation with MHD (r = - 0.33) and MLD (r = - 0.34), respectively. They were also significant in multivariate analysis (P < 0.001). Elderly and less VC were independent predictors of increasing absolute residuals (AR). The VC model showed no significant difference in AR compared to the model using the CT parameter of lung volume in FB (LV-FB): median AR of the LV-FB model vs. the VC model was 0.12 vs. 0.11 Gy (P = 0.79). On the other hand, the median AR of the MLD model was 0.38 Gy, showing no specific subgroups of larger AR. CONCLUSION: Preoperative spirometry and BMI are significant predictors of MHD and MLD, respectively. Although elderly and low-VC patients may have larger predictive variations, spirometry might be a substitute for LV-FB as a predictor of MHD.

Fully automated rigid image registration versus human registration in postoperative spine stereotactic body radiation therapy: a multicenter non-inferiority study.

To confirm the fully automated rigid image registration (A-RIR) accuracy in postoperative spine stereotactic body radiation therapy (SBRT), we conducted a multicenter non-inferiority study compared to the human rigid image registration (H-RIR). Twenty-eight metastatic cancer patients who underwent postoperative spine SBRT are enrolled-image registration (IR) of planning computed tomography (CT) and CT-myelogram for delineating the spinal cord. The adopted A-RIR workflow is a contour-focused algorithm performing a rigid registration by maximizing normalized mutual information (NMI) restricted to the data contained within the automatically extracted contour. Three radiation oncologists (ROs) from multicenters were prompted to review two blinded registrations and choose one for clinical use. Indistinguishable cases were allowed to vote equivalent, counted A-RIR side. A-RIR is considered non-inferior to H-RIR if the lower limit of the 95% confidence interval (CI) of A-RIR preferable/equivalent is greater than 0.45. We also evaluated the NMI improvement from the baseline and the translational/rotational errors between A-RIR and H-RIR. The A-RIR preferable/equivalent was selected in 21 patients (0.75, 95% CI: 0.55-0.89), demonstrating non-inferiority to H-RIR. The A-RIR's NMI improvement was greater than H-RIR in 24 patients: the mean value ± SD was 0.225 ± 0.115 in A-RIR and 0.196 ± 0.114 in H-RIR (P < 0.001). The absolute translational error was 0.38 ± 0.31 mm. The rotational error was -0.03 ± 0.20, 0.05 ± 0.19, -0.04 ± 0.20 degrees in axial, coronal, and sagittal planes (range: -0.66-0.52). In conclusion, A-RIR shows non-inferior to H-RIR in CT and CT-myelogram registration for postoperative spine SBRT planning.