Dosimetric effects of small field size, dose grid size, and variable split-arc methods on gamma pass rates in radiation therapy.

This study investigates the influence of calculation accuracy in peripheral low-dose regions on the gamma pass rate (GPR), utilizing the Acuros XB (AXB) algorithm and ArcCHECK™ measurement. The effects of varying small field sizes, dose grid sizes, and split-arc techniques on GPR were analyzed. Various small field sizes were employed. Thirty-two single-arc plans with dose grid sizes of 2 mm and 1 mm and prescribed doses of 2, 5, 10, and 20 Gy were calculated using the AXB algorithm. In total, 128 GPR plans were examined. These plans were categorized into three sub-fields (3SF), four sub-fields (4SF), and six sub-fields (6SF). The GPR results deteriorated with smaller target sizes and a 2 mm dose grid size in a single arc. A similar degradation in GPR was observed with smaller target sizes and a 1 mm dose grid size. However, the 1 mm dose grid size generally resulted in better GPR compared with the 2 mm dose grid size for the same target sizes. The GPR improved with finer split angles and a 2 mm dose grid size in the split-arc method. However, no statistically significant improvement was observed with finer split angles and a 1 mm dose grid size. This study demonstrates that coarser dose grid sizes result in lower GPRs in peripheral low-dose regions as calculated by AXB with ArcCHECK™ measurement. To enhance GPR, employing split-arc methods and finer dose grid sizes could be beneficial.

Therapeutic efficacy of selective intraarterial chemoradiotherapy with docetaxel and nedaplatin for human papilloma virus-negative oropharyngeal cancer.

OBJECTIVE: Human papilloma virus-negative oropharyngeal cancer has not achieved satisfactory outcomes compared with those of human papilloma virus-positive oropharyngeal cancer. This study evaluated the therapeutic efficacy of selective intraarterial chemoradiotherapy with the docetaxel and nedaplatin regimen for human papilloma virus-negative oropharyngeal cancer. METHODS: Twenty-two consecutive patients with human papilloma virus-negative oropharyngeal cancer who had undergone selective intraarterial chemoradiotherapy were retrospectively analyzed. The primary tumor and whole neck were irradiated (50 Gy). Subsequently, the primary site and metastatic lymph nodes were boosted by 20 Gy. The intraarterial chemotherapy regimen comprised a combination of nedaplatin (80 mg/m2) and docetaxel (60 mg/m2), which was initially administered at the start of radiotherapy and was given every 4 weeks for three sessions. Each intraarterial dose of an anticancer agent was determined according to the percentage of the tumor volume supplied by the target artery to the total tumor volume, which was intraoperatively measured via cone-beam computed tomography. The outcome measures were locoregional control, disease-free survival, and overall survival rates and adverse events. Statistical analyses were performed using the Kaplan-Meier method. RESULTS: The median follow-up period was 59 (range, 15-103) months. The T stage was T1/T2 in 5 patients (23%), T3 in 5 patients (23%), and T4 in 12 patients (54%). Cervical lymph node metastasis was staged as ≥N2c in 7 (32%) patients. Complete response was achieved in all patients at the first imaging examination after intraarterial chemoradiotherapy. The 5-year locoregional control, disease-free survival, and overall survival rates were 96% (95% confidence interval, 0.72-0.99), 91% (95% confidence interval, 0.68-0.98), and 100% (95% confidence interval, not available), respectively. Regarding serious acute adverse events, grade 4 laryngeal edema and leukopenia were observed in 1 (5%) and 11 patients (50%), respectively. No other serious acute adverse events were observed. CONCLUSION: Selective intraarterial chemoradiotherapy with docetaxel and nedaplatin has the potential to achieve favorable locoregional control, disease-free survival, and overall survival rates in human papilloma virus-negative oropharyngeal cancer.

Palliative Radiation Therapy without Chemotherapy for a Patient with Monomorphic Epitheliotropic Intestinal T Cell Lymphoma: A Case Report.

Monomorphic epitheliotropic intestinal T cell lymphoma (MEITL), which used to be known as type 2 enteropathy-associated T cell lymphoma, is a rare lymphoma and is generally treated with chemotherapy. However, the MEITL prognosis is poor, and intestinal lymphoma including MEITL has the risk of bowel perforation not only at presentation but also during chemotherapy. A 67-year-old man was diagnosed with MEITL after presenting in our emergency room with bowel perforation. He and his family did not opt for the administration of anticancer drugs because of the risk of bowel perforation. However, they wanted the patient to receive palliative radiation therapy without chemotherapy. This treatment shrunk the tumor size without causing severe complications or decline in the quality of life, until he accidentally died due to traumatic intracranial hematoma. Considering the potential efficacy and safety of this treatment, it should be studied in more patients with MEITL.

Patterns of recurrence after low-dose postoperative radiotherapy for head and neck squamous cell carcinoma.

BACKGROUND: Postoperative chemoradiotherapy is recommended for patients with head and neck squamous cell carcinoma with positive margins or extracapsular extension at high risk of recurrence. However, high-dose radiotherapy in the head and neck region often causes severe acute and late radiation-related adversities. In our institution, the radiation dose has been relatively lower than that used in Western countries to reduce radiation-related toxicities. Therefore, in this study, we examined the treatment outcomes of low-dose postoperative chemoradiotherapy. METHODS: The outcomes of 90 consecutive head and neck squamous cell carcinoma patients who received postoperative radiotherapy between June 2009 and December 2016 were retrospectively analyzed. All patients received postoperative three-dimensional conformal radiotherapy with or without concurrent systemic chemotherapy. The median patient age was 65 years. Concurrent chemoradiotherapy was administered at a total dose of 50.4 Gy in 28 fractions (daily fraction, 1.8 Gy). High-risk patients received 10.8 Gy of boost irradiation in six fractions. For radiotherapy alone, the irradiation dose was up to 54 Gy in 30 fractions and 64.8 Gy in 36 fractions for high-risk patients to increase the treatment intensity. RESULTS: The median follow-up period was 40.5 months. The 3-year locoregional control and overall survival rates were 67.5% and 82.7%, respectively. A significantly higher proportion of patients with oral cavity carcinoma experienced locoregional failure (p = 0.004). The acute adverse events were mild, and the only late adverse event was grade 3 dysphagia (n = 3). CONCLUSION: This study suggests that de-escalation of the postoperative radiation dose can potentially reduce the severe adverse events of irradiation in patients while ensuring its effectiveness. In patients with oral cavity carcinoma, it might be necessary to increase the radiation dose.

Chemoembolization for Symptomatic Metastatic Epidural Spinal Cord Compression Refractory to Re-radiotherapy.

PURPOSE: To evaluate the efficacy of chemoembolization for inoperable metastatic epidural spinal cord compression (MESCC) refractory to re-radiotherapy. METHODS: Nineteen consecutive patients with recurrent MESCC after re-radiotherapy who had undergone chemoembolization were retrospectively analyzed. Outcome measures were pain relief rate, neurological improvement rate, objective response rate, and adverse events. MESCC degree classification was assessed using Bilsky grades. Pain assessment was performed using Numerical Rating Scale, and neurological function was evaluated using the Frankel classification. RESULTS: The median follow-up period was 7 (range 2-44) months. All participants had MESCC grade 2 or higher and had severe pain. Fifteen patients (79%) had neurological deficits, and ten had Frankel classification C and five had D. Symptoms were relieved in almost all patients the day following chemoembolization. Pain relief was achieved in 18 of 19 (95%) patients; the median decrease in Numerical Rating Scale score was 8 (range 0-10; p < 0.001). Neurological improvement was achieved in 11 of 15 patients (73%); the median increase in Frankel classification was 1 (range 0-2; p = 0.006). Ten of 19 (53%) patients showed a reduction in MESCC; the median decrease in Bilsky grade was 1 (range 0-2; p = 0.005). There was no correlation between the change in Bilsky grade and pain relief (p = 0.421). However, the decrease in Bilsky grade significantly improved neurological symptoms (p = 0.01). No serious adverse events occurred. CONCLUSION: Chemoembolization may be a useful palliative treatment modality for MESCC refractory to re-radiotherapy. LEVEL OF EVIDENCE: Level 3b, Follow up Study.

Different indocyanine green fluorescence patterns of two skin metastases of hypopharyngeal squamous carcinoma: A case report.

BACKGROUND: Skin metastasis from primary squamous cell carcinoma of the head and neck is rare . These metastatic lesions are usually detected by physical examination, ultrasound imaging, computed tomography, and positron emission tomography.. Recently, indocyanine green fluorescence angiography (ICG-FA) has been used to discover superficial tumors. However, the optimum timing of ICG injection and fluorescence patterns of skin tumors in ICG-FA are still unknown. CASE PRESENTATION: We encountered a 60-year-old man with hypopharyngeal squamous cell carcinoma. The patient underwent concurrent chemotherapy, radiotherapy, and surgery. However, following these treatments, the patient developed two nodules in the skin of the right upper limb. Thus, the patient underwent ICG-FA. The two skin metastatic nodules showed different fluorescence patterns. One lesion showed high fluorescence intensity during ICG-FA. However, the fluorescence intensity of a small part of the other lesion exceeded that of the surrounding tissue only for a short time. CONCLUSION: We suggest that ICG-FA is effective for detecting skin metastases, and with further studies on the various fluorescence patterns of skin tumors, this technique will become more efficient.

Predictive factors of posttreatment fracture by definitive radiotherapy for uterine cervical cancer.

PURPOSE: Fractures are known to shorten life expectancy and worsen the quality of life. The risk of fractures after radiation therapy in cervical cancer patients is known to be multifactorial. In this study, we examined risk factors for fractures in cervical cancer patients, especially by evaluating bone densities and DVH parameters for fractured bones. MATERIALS AND METHODS: For 42 patients, clinical characteristics, pretreatment CT bone densities, and radiation dose were compared between patients with and without fractures. RESULTS: Posttreatment fractures occurred in 25 bones among ten patients. Pretreatment CT bone densities were significantly lower in patients with fractures (P < 0.05-0.01 across sites, except for the ilium and the ischium). Although DVH parameters were also significantly associated with fractures in univariate analysis, only CT densities were significantly associated with fractures in multivariate analysis. CONCLUSION: Pretreatment CT densities of spinal and pelvic bones, which may reflect osteoporosis, have a significant impact on the risk for posttreatment fractures.

Transarterial Chemoembolization for the Palliation of Painful Bone Metastases Refractory to First-Line Radiotherapy.

PURPOSE: To compare the efficacy and safety of transarterial chemoembolization for the palliation of radiotherapy (RT)-failure bone metastases (BMs) with those of re-radiotherapy (Re-RT) in achieving pain relief. MATERIALS AND METHODS: Fifty consecutive patients with RT-failure BMs who had undergone Re-RT (23 patients) and transarterial chemoembolization (27 patients) were retrospectively analyzed. The primary endpoint was clinical response, and the secondary endpoints were objective response and adverse events. Pain assessment was performed using the numerical rating scale, and tumor response was evaluated using the modified Response Evaluation Criteria in Solid Tumors. Pain relief was defined as lack of pain with no analgesic usage (complete pain response) or a decrease in pain score by ≥3 points with analgesic usage (partial pain response). RESULTS: The pain relief rates in the Re-RT and transarterial chemoembolization groups were 57% and 92%, respectively (P = .006). The median pain relief duration was 2 and 3 months in the Re-RT and transarterial chemoembolization groups, respectively (P = .002). The 6-month pain-free survival rates were 30% and 51% in the Re-RT and transarterial chemoembolization groups, respectively (P = .08). The median tumor reduction rates were -4% and 9% in the Re-RT and transarterial chemoembolization groups, respectively (P < .001). The objective response rates were 0% and 11% in the Re-RT and transarterial chemoembolization groups, respectively (P = .29). No serious adverse events or complications were observed. CONCLUSIONS: Transarterial chemoembolization achieved a superior response rate and longer duration of palliation in symptomatic RT-failure BMs.

Indocyanine green fluorescence angiography for detection of cutaneous angiosarcoma of the scalp: A case report.

Cutaneous angiosarcoma is a rare neoplasm. One important predictor of recurrence is the resection margin; however, identifying the tissue area containing malignant cells is difficult. Indocyanine green fluorescence angiography (ICG-FA) has been used to identify superficial malignancies, including malignant tumors in the liver and sentinel lymph node metastasis of breast cancer. ICG-FA is also used to identify and define the resection margin of cutaneous angiosarcomas. However, there are currently only a few reports on the application of ICG-FA for detecting cutaneous angiosarcomas. We report a case of cutaneous angiosarcoma in the scalp in which one lesion, located in the parietal scalp, showed high fluorescence intensity corresponding exactly with the lesion was defined by physical examination, whereas the malignant area of the second lesion, located in the occipital scalp, was revealed more accurately by ICG-FA than by physical examination. Further, the second lesion was the first case diagnosed as angiosarcoma by the limited-area biopsy for a high-intensity area of ICG-FA. By determining where ICG is located within cutaneous angiosarcomas and quantitating the ICG intensity level corresponding to the malignant area, ICG-FA could be a promising tool for identifying cutaneous angiosarcomas.

Definitive radiotherapy consisting of whole pelvic radiotherapy with no central shielding and CT-based intracavitary brachytherapy for cervical cancer: feasibility, toxicity, and oncologic outcomes in Japanese patients.

BACKGROUND: This prospective study investigated the feasibility, toxicity, and oncologic outcomes of definitive radiotherapy (RT) consisting of whole pelvic radiotherapy with no central shielding (noCS-WPRT) and CT-based intracavitary brachytherapy (ICBT) in Japanese patients with cervical cancer. METHODS: Patients with cervical cancer of FIGO stages IB1-IVA were eligible. The treatment protocol consisted of noCS-WPRT of 45 Gy in 25 fractions and CT-based high dose-rate ICBT of 15 or 20 Gy in 3 or 4 fractions prescribed at point A. The prescribed ICBT dose was decreased if the manual dwell time/position optimization failed to meet organs-at-risk constraints. Graphical optimization and additional interstitial needles were not applied. RESULTS: We enrolled 40 patients. FIGO stages were IB1: 11, IB2: 13, IIA2: 1, IIB: 11, IIIB: 3, and IVA: 1. Median (range) pretreatment tumor diameter was 47 (14-81) mm. Point A doses were decreased in 19 of 153 ICBT sessions (12%). The median follow-up duration was 33 months. The 2-year rates of pelvic control, local control (LC), and progression-free survival were 83%, 85%, and 75%, respectively. Pre-ICBT tumor diameter, high-risk clinical target volume (HR-CTV), total HR-CTV D90, and overall treatment time (OTT) significantly affected LC. Late adverse events (grade ≥ 3) were observed in 3 patients (2 in the bladder, 1 in the rectum). CONCLUSIONS: Definitive RT consisting of noCS-WPRT and CT-based ICBT was feasible for Japanese patients with cervical cancer. To further improve LC, additional interstitial needles for patients with a large HR-CTV and shorter OTT should be considered.

Analyses of size and computed tomography densitometry parameters for prediction of keloid recurrence after postoperative electron beam radiation therapy.

BACKGROUND: The lesion size is a risk factor for keloid recurrence after postoperative radiotherapy. However, it remains unclear whether the major axis diameter is the most appropriate parameter to evaluate lesion size, because keloids are often irregular in shape. Additionally, no previous study has investigated computed tomography (CT) densitometry parameters of keloids as potential predictors for recurrence after postoperative radiotherapy. MATERIALS AND METHODS: The size and CT densitometry parameters were measured for 74 lesions with CT images of sufficient quality for evaluation. The association between recurrence and size or CT densitometry parameters was analyzed for 64 lesions that could be followed up for 6 months or more. RESULTS: The major axis diameter × minor axis diameter × thickness showed the strongest correlation with volume (ρ = 0.96, P < .0001). The median follow-up period was 71 months, and 17 lesions recurred. The major axis diameter × minor axis diameter × thickness ≥2.5 cm3 (hazard ratio = 5.9, P = .0052) and volume ≥1.2 ml (hazard ratio = 4.3, P = .029) were significantly associated with keloid recurrence under multivariate analyses, while the major axis diameter alone were not. The mean and maximum CT values, and the kurtosis and skewness of density histogram were not significantly different between recurrent and non-recurrent lesions. CONCLUSION: The major axis diameter × minor axis diameter × thickness may be a better parameter than the major axis diameter alone. CT densitometry analyses may not help to predict keloid recurrence after postoperative electron beam radiotherapy.

Concomitant radiotherapy and transarterial chemoembolization reduce skeletal-related events related to bone metastases from renal cell carcinoma.

OBJECTIVES: The purpose of this study was to compare the efficacy of radiotherapy (RT) combined with transcatheter arterial chemoembolization (TACE) with RT alone for the treatment of bone metastases from renal cell carcinoma (RCC). METHODS: We included in this retrospective study 25 RCC patients (28 bone metastases), who were treated with RT at our institution. Patients were divided into two groups: patients treated with RT alone (monotherapy group; n = 17) and those treated with RT combined with TACE (combined therapy group; n = 11). The administered median RT dose was 30 Gy in 10 fractions. Anti-cancer agents used in TACE were cisplatin (median dose, 50 mg) and carboplatin (median dose, 240 mg) for patients with reduced renal function. We evaluated the objective response, post-RT-skeletal-related event (PR-SRE)-free rate, and adverse events associated with treatment for each group. RESULTS: The objective response rates for bone metastases in the monotherapy and combined therapy groups were 33% and 82%, respectively (p = 0.009). The 2-year PR-SRE-free rate in the monotherapy and combined therapy groups was 41.8% and 100%, respectively (p = 0.009). The objective response and PR-SRE-free rates were significantly superior in the combined therapy than in the monotherapy group. There were no significant differences in adverse events or survival between the two groups. CONCLUSION: RT combined with TACE is a promising treatment for bone metastases from RCC, as it results in higher objective response, and PR-SRE-free rates compared with RT alone. KEY POINTS: • Skeletal-related events (SREs) are common in patients with bone metastases from renal cell carcinoma (RCC). • Radiotherapy (RT) provides pain relief in patients with bone metastases from RCC, but rarely achieves objective response. • Combination of RT with transcatheter arterial chemoembolization results in higher objective response and post-RT-SRE-free rates compared with RT alone and is a promising treatment for bone metastases from RCC, as it.

Appropriate radiation dose for symptomatic relief and local control in patients with adult T cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive peripheral T-cell neoplasm that occurs only in patients with human T-cell leukemia virus type 1. No large study or randomized trial investigating radiotherapy (RT) for ATL has been performed. We retrospectively reviewed 55 courses of RT for 41 consecutive patients with ATL who underwent RT between 2000 and 2016 at our institutions. The results showed that RT for local ATL lesions can achieve symptomatic improvement in 92% of cases. Local remission, either complete remission (CR) or partial response (PR), was achieved in 100% of the patients (CR: 89%, PR: 11%) with ≥40 Gy irradiation. CR or PR was achieved in 71% (CR: 29%, PR: 43%) with 30-39 Gy and in 73% (CR: 6.7%, PR: 67%) with ≤29 Gy irradiation. The mean total radiation dose in the CR and PR groups differed significantly (38 vs 25 Gy, P = 0.0002). The maximum acute toxicity was Grade 0-2 in all patients, except for one patient experienced Grade 3 radiation dermatitis. In-field relapses occurred in 36% of patients, and the frequency of in-field relapses was 11%, 30% and 71% among those who achieved CR, PR and SD, respectively. All 9 patients who received total skin irradiation experienced cutaneous relapses, with a median of 63 days (range, 7-210 days). Almost all (39 of 41) patients with ATL experienced out-of-field progression after RT. In conclusion, RT was confirmed to be effective and safe for palliative treatment of local ATL lesions.

Radiation-induced dermatitis after administration of mogamulizumab for adult T-cell leukaemia/lymphoma: a multi-institutional retrospective study.

BACKGROUND: Cutaneous adverse reactions are frequently induced by mogamulizumab. Cases of Stevens-Johnson syndrome, toxic epidermal necrolysis and severe photosensitivity related to mogamulizumab have been reported. This study investigated whether severe radiation-induced dermatitis occurred in patients undergoing radiotherapy after the administration of mogamulizumab for adult T-cell leukaemia/lymphoma. METHODS: We retrospectively reviewed 46 courses of radiotherapy administered to 15 consecutive patients with adult T-cell leukaemia/lymphoma (acute, n = 7; lymphoma, n = 7; smouldering, n = 1) who received mogamulizumab before or during radiotherapy at three institutions between 2012 and 2017. RESULTS: During 43 of the 46 radiotherapy courses, patients developed Grade ≤1 radiation-induced dermatitis. No patient developed Grade ≥3 radiation-induced dermatitis. No patient was prescribed ointments as prophylactic treatment for radiation-induced dermatitis. Development of radiation-induced dermatitis was not significantly associated with the number of days since the administration of mogamulizumab prior to radiotherapy (P = 0.85), frequency of administration of mogamulizumab before/during radiotherapy (P = 0.33), administration of mogamulizumab during radiotherapy (P = 0.41) or types of lesions in adult T-cell leukaemia/lymphoma cases (cutaneous vs. non-cutaneous, P = 0.74). Development of radiation-induced dermatitis was significantly related to the total cutaneous dose (mean, 31.9 Gy [95% confidence interval: 26.6-37.1 Gy] vs. 19.7 Gy [95% confidence interval: 16.2-23.2 Gy], P = 0.0004) and total prescribed dose (mean, 31.5 Gy [95% confidence interval: 26.2-36.8 Gy] vs. 18.5 Gy [95% confidence interval: 15.0-22.0 Gy], P = 0.0002). CONCLUSION: None of the 15 patients who received moderate-dose radiotherapy developed severe radiation-induced dermatitis during the 46 courses of radiotherapy after mogamulizumab administration.

Computed tomography-based image-guided brachytherapy for cervical cancer: correlations between dose-volume parameters and clinical outcomes.

This study evaluated the oncologic outcomes and complications of cervical cancer patients in terms of CT-based image-guided brachytherapy (IGBT) parameters. Of 68 cervical cancer patients treated with definitive radiotherapy/concurrent chemoradiotherapy, most received whole-pelvis external beam RT (EBRT) of 40 Gy in 20 fractions, pelvic EBRT with central shield of 10 Gy in 5 fractions, and CT-based IGBT of 18 Gy in 3 fractions prescribed to point A. Cumulative EBRT and IGBT doses were calculated as the total equivalent dose in 2 Gy fractions (EQD2). The median follow-up was 31 (3-52) months. The 2-year overall survival, local control, pelvic control, and disease-free survival rates of the 68 patients were 92%, 83%, 82% and 73%, respectively. The HR-CTV D90, length from the tandem axis to left/right margin of the HR-CTV (T-LR), and HR-CTV volume were significant IGBT parameters for predicting local/pelvic control. Patients who received an HR-CTV D90 of >60 Gy, compared with ≤60 Gy, had significantly better local/pelvic control. Furthermore, 70 Gy was a marginally significant HR-CTV D90 cut-off affecting local control. T-LR was an independent IGBT parameter predicting local/pelvic control on multivariate analysis. Three patients developed Grade 3 or higher treatment-related complications. The D2cm3 of organs at risk were not significant predictors of complications. Future challenges for further improving outcomes include additional interstitial needles for irregularly shaped HR-CTVs, and moderate dose escalation, especially for patients with poor tumor responses.