Factors associated with cavity formation after stereotactic body radiation therapy for peripheral early-stage lung cancer.

PURPOSE: This retrospective study aimed to identify the factors associated with cavity formation after SBRT in peripheral early-stage lung cancer patients. We analyzed the occurrence of cavity changes after SBRT. MATERIALS AND METHODS: We examined 99 cases with T1-T2aN0 peripheral non-small cell lung cancer treated with SBRT from 2004 to 2021. Patients underwent respiratory function tests, including diffusing capacity for carbon monoxide (DLco), before treatment. The median observation period was 35 months (IQR 18-47.5 months). Treatment involved fixed multi-portal irradiation in 67% of cases and VMAT in 33%. The total radiation doses ranged from 42 to 55 Gy, delivered over 4 to 5 fractions. RESULTS: Cavity formation occurred in 14 cases (14.1%), appearing a median of 8 months after SBRT. The cavity disappeared in a median of 4 months after formation. High DLco and total radiation dose were identified as factors significantly associated with cavity formation. There have been no confirmed recurrences to date, but one patient developed a lung abscess. CONCLUSION: Although cavity formation after SBRT for peripheral early-stage lung cancer is infrequent, it can occur. This study showed high DLco and total radiation dose to be factors significantly associated with cavity formation. These findings can be applied to optimizing radiation therapy (RT) and improving patient outcomes. Further research is needed to determine the optimal radiation dose for patients with near-normal DLco for whom surgery is an option. This study provides valuable insights into image changes after RT.

Study of prostate-specific antigen levels during salvage radiotherapy after prostate cancer surgery.

BACKGROUND: Administration of adjuvant or salvage radiotherapy (RT) after prostate cancer (PCa) surgery is supported by clinical evidence and is a widely adopted strategy. On occasion, we detect changes in prostate-specific antigen (PSA) levels, such as a transient elevation or decline, during RT. Thus, we retrospectively investigated the frequency of changes in PSA levels, their associations with histopathological parameters, PSA doubling time (PSADT), and biochemical recurrence (BR) of PCa. METHODS: This study included 23 consecutive patients who underwent surgery for PCa between 2012 and 2019, received salvage RT without hormone therapy, and exhibited changes in PSA levels during RT. The prostatic bed was irradiated with a total dose of 64 to 66 Gy. BR was defined as consecutive PSA levels exceeding 0.2 ng/mL or having to start hormone therapy because of PSA elevation after salvage RT. RESULTS: During salvage RT after PCa surgery, PSA levels transiently increased in 11 patients (47.8%) and decreased in 12 (52.2%). When factors associated with BR were examined in patients with transient PSA elevation, seminal vesicle invasion and preoperative PSA values were identified as being statistically significant. When factors for BR were examined in patients with a decline in PSA levels, the Gleason score and PSADT were identified as being significant. Among the cases of a decline in PSA levels during salvage RT, those who received a radiation dose of less than 36 Gy did not experience BR. Similarly, patients who exhibited changes in PSA levels during salvage RT and did not have perineural invasion did not experience BR. CONCLUSION: This is the first study to examine the histopathological factors possibly affecting BR in patients undergoing salvage RT after PCa surgery. The results indicate that in patients with transient PSA elevation, seminal vesicle invasion is a significant risk factor. On the other hand, in patients with a decline in PSA levels during irradiation, the Gleason score and perineural invasion were found to be potential risk factors for BR. These findings suggest that a thorough examination of postoperative histopathological results may be necessary for the optimal management of patients with PCa.

Radiation therapy for vaginal cancer in complete uterine prolapse with intrauterine adhesion: a case report.

BACKGROUND: We encountered a woman with vaginal cancer that was associated with complete uterine prolapse and complicated by severe intrauterine adhesions. In this case report, we describe the clinical course and successful treatment of this rare condition. CASE PRESENTATION: A 78-year-old woman (gravida 10, para 2, abortion 8) with a 10-year history of uterine prolapse presented for evaluation of bleeding from an ulceration on the surface of the irreducibly prolapsed uterus. Biopsy of a mass on her vaginal wall led to a diagnosis of keratinizing squamous cell carcinoma. Her history of eight abortion procedures had resulted in severe intrauterine adhesions, preventing tandem insertion and intracavitary brachytherapy. She was also ineligible for surgery under general anesthesia + chemotherapy because of her advanced age and presence of arrhythmia. Therefore, we devised an extensive treatment plan involving high-dose-rate interstitial brachytherapy. This treatment successfully eliminated the squamous cell carcinoma as confirmed by biopsy with no recurrence or severe late complications. CONCLUSIONS: We found that high-dose-rate interstitial brachytherapy may be a very effective therapeutic strategy for this condition with few adverse effects.

Roles of Ki-67 and p16 as biomarkers for unknown primary head and neck squamous cell carcinoma.

PURPOSE: Treatment guidelines have not been established for unknown primary head and neck squamous cell carcinoma (SCC). For these patients, chemoradiotherapy (CRT) can provide a better prognosis than that for patients with other head and neck cancers. The presence of HPV in the tumor is associated with a better outcome. However, not all patients with HPV-positive unknown primary head and neck SCC experience good treatment outcomes in actual clinical settings. METHODS: We thus retrospectively determined the Ki-67 proliferation index and p16 expression status to assess the associations of these parameters with treatment outcomes of patients with unknown primary head and neck SCC. RESULTS: The subjects were 13 patients who underwent CRT after surgery or excision biopsy between 1999 and 2016. The 2- and 5-year overall survival (OS) rate was 76.9% and 68.4%, respectively. The prognostic factor was age. There was no significant difference in survival between patients with a high Ki-67 vs. low Ki-67 or between patients with p16-positive vs. p16-negative metastases OS. However, all p16-positive patients with low Ki-67 showed good locoregional control. CONCLUSIONS: The combination of ki67 expression and p16 expression status may allow prediction of local control more accurately than p16 expression status alone.

A long-surviving patient with advanced esophageal basaloid squamous cell carcinoma treated only with radiotherapy: case report and literature review.

BACKGROUND: Esophageal basaloid squamous cell carcinoma (EBSCC) is a rare malignant disease. Advanced EBSCC (AEBSCC) has a poorer prognosis than the more common esophageal squamous cell carcinoma, but no treatment policy has yet been established. This is the first reported case with AEBSCC treated only with radiotherapy. Thus, our long-surviving patient merits consideration. We therefore reviewed cases with the same stage of AEBSCC for further investigation. CASE PRESENTATION: An 85-year-old man with a chief complaint of difficulty swallowing foods was diagnosed with AEBSCC, cT3N1M0, stage III, by thorough examination. The basaloid carcinoma extended from the upper thoracic esophagus to the middle thoracic esophagus based on imaging studies, endoscopy and biopsy. Morphologically, the tumor was an elevated ulcerative area. We conducted radiotherapy to relieve symptoms, as the patient and his family refused aggressive treatment. He has remained alive without recurrence for 2 years, to date, after completing radiotherapy. CONCLUSIONS: Basaloid carcinoma might be highly sensitive to radiotherapy. Thus, radiotherapy for local control might be beneficial for elderly patients with complications and those refusing aggressive treatment.

Successful Pregnancy and Delivery After Radiation With Ovarian Shielding for Acute Lymphocytic Leukemia Before Menarche.

Total body irradiation is performed as a preconditioning regimen to inhibit graft-versus-host disease after bone marrow transplantation and to eradicate remaining tumor cells. However, these regimens result in delayed secondary sex characteristics and failure of ovarian function recovery, leading to amenorrhea and infertility. Herein, we report a case of an 11-year-old girl diagnosed with acute lymphocytic leukemia who received induction chemotherapy and prophylactic cranial irradiation. For bone marrow transplantation, she received total body irradiation of 12 Gy with uterine and ovarian shielding at 13 years of age. The patient remained in remission and menarche began at 14 years of age. At 23, she became pregnant and delivered a baby naturally with no abnormalities.

Solitary pulmonary metastasis from prostate cancer with neuroendocrine differentiation: a case report and review of relevant cases from the literature.

BACKGROUND: Solitary lung metastasis from prostate cancer is rare. There are few reports of such cases with neuroendocrine differentiation. CASE PRESENTATION: A 50-year-old man presented to our hospital with a chief complaint of dysuria. Histological examination revealed prostate cancer, which was classified as cT4 N0 M0, stage IV adenocarcinoma. Since the patient was at high risk, endocrine and radiation therapies were started. One year after starting radiation therapy, the patient developed bloody sputum. Chest radiography revealed a nodular shadow in his left lung (S5). Although 18-fluoro-2-deoxyglucose positron emission tomography revealed abnormal accumulation in the lesion, the cytological diagnosis was class IIIa, which did not yield a definitive diagnosis. Given that prostate specific antigen (PSA) was not elevated, a primary lung tumor was suspected, and thoracoscopic segmental resection of the lung was performed with lymph node dissection. The final pathological diagnosis was solitary lung metastasis from prostate cancer with neuroendocrine differentiation and mediastinal lymph node metastasis. The specimen showed a mixed pattern of conventional prostatic and neuroendocrine carcinomas. CONCLUSION: We herein report a case with neuroendocrine differentiation (NED), along with a review of the relevant literature, including histopathological findings. According to previous case reports, some patients with solitary lung metastasis from prostate cancer achieved relatively good long-term survival. We consider establishing the correct diagnosis and implementing an appropriate treatment plan to be essential in prostate cancer patients with oligometastases that have the potential to be neuroendocrine (NE) tumors.

Patterns of practice in the radiation therapy for bladder cancer: survey of the Japanese Radiation Oncology Study Group (JROSG).

OBJECTIVE: To retrospectively analyze the clinical outcomes of radiation therapy with or without chemotherapy for bladder cancer in Japan. METHODS: A questionnaire-based survey of patients with pathologically proven bladder cancer treated by definitive radiation therapy between 2002 and 2006 was conducted by the Japanese Radiation Oncology Study Group, and the clinical records of 159 patients were collected from 17 institutions. Concurrent intra-arterial chemoradiotherapy and concurrent systemic chemoradiotherapy were administered in 51 and 33 patients, respectively. RESULTS: The 5-year overall survival and bladder preservation rates were 48 and 39%, respectively. Eighty-nine (56%) patients developed recurrence (bladder, 48; regional lymph nodes, 4; distant sites, 41). The results of multivariate analysis revealed that adoption of chemotherapy was the only significant prognostic factor for overall survival (relative risk = 0.615 [95% confidence interval: 0.439-0.862], P = 0.005). The type of chemotherapy administered did not significantly affect the local control or overall survival rates. The actuarial 5-year overall survival rates and bladder preservation in the radiation therapy combined with intra-arterial chemotherapy group were 64 and 58%, respectively, and the corresponding rates in the radiation therapy combined with systemic chemotherapy group were 67 and 42%, respectively. CONCLUSIONS: The results of this survey revealed the current status of practice of radiation therapy for bladder cancer in Japan. A multi-institutional prospective study is needed based on the results of this study to determine the optimal radiotherapeutic approach, including the need for concurrent chemotherapy and the appropriate chemotherapy regimen for invasive bladder cancer.

Unexpected change in hydrogel spacer volume during external-beam radiation therapy.

PURPOSE: To reduce the rectal radiation dose during local radiation therapy of prostate cancer, a hydrogel spacer is typically implanted between the prostate and rectum. However, the spacer volume can change during external beam radiation therapy (EBRT). Therefore, we used magnetic resonance imaging (MRI) to determine changes in the spacer volume during EBRT and analyzed the data to identify patient factors influencing this change. MATERIALS AND METHODS: A hydrogel spacer was implanted in each enrolled patient diagnosed with prostate cancer (n = 22, age = 69-86 years) for EBRT with a total dose of 70 Gy over 35 fractions. T2-weighted MRI images were acquired before (median = 8 days) and during EBRT, when the radiation dose of 48 Gy (median) was given at 55 days (median) after implantation. MRI images were used to determine the spacer volume as well as the maximum and minimum distances between the prostate and anterior wall of the rectum at the middle height of the prostate. Scatterplots were created to determine whether correlations existed between changes in the spacer volume and these two distances, while uni- and multivariate analyses were conducted to determine if the spacer volume change was influenced by the following patient factors: age, body mass index, estimated glomerular filtration rate, and visceral fat areas at the umbilical and femoral head positions. RESULTS: The spacer volume increased in all 22 patients, with the smaller spacer volume before EBRT increasing by a larger amount during EBRT. This increase in the spacer volume was unaffected by other patient factors. However, it correlated with the change in the maximum distance between the prostate and anterior wall of the rectum. CONCLUSION: To avoid adverse changes in the rectal radiation dose during EBRT, hydrogel spacer volume should be monitored, especially if the pre-EBRT volume is small.

Next-generation sequencing of primary testicular lymphoma and relapse in the glans penis after prophylactic radiation therapy: a rare case report.

BACKGROUND: Primary testicular lymphoma (PTL) is relatively rare. The contralateral testis is a common site of PTL relapse; therefore, once complete remission is achieved, radiation therapy (RT) is administered to the contralateral testis to prevent relapse. CASE PRESENTATION: A 76-year-old man was diagnosed with PTL and received RT as described above. However, despite achieving and maintaining complete remission, a mass diagnosed as diffuse large B-cell lymphoma by tissue biopsy developed in the glans penis 6.5 years after prophylactic RT. We investigated whether the glans penile lymphoma was PTL relapse or a new malignancy by genomic analysis using next-generation sequencing of DNA extracted from two histopathological specimens. CONCLUSIONS: We found the same variant allele fraction in four somatic genes (MYD88, IL7R, BLNK, and FLT3) at similar frequencies, indicating that the glans penile lymphoma had the same origin as the PTL. To the best of our knowledge, this is the first case report of PTL relapse in the glans penis.

Pulmonary Veno-Occlusive Disease after Autologous Stem Cell Transplantation.

Pulmonary veno-occlusive disease (PVOD) is an extremely rare condition in oncology practice. Although PVOD is clinically similar to pulmonary arterial hypertension, the conditions differ in terms of pathophysiology, management, and prognosis. This report discusses the case of a 47-year-old woman who developed dyspnea and fatigue after high-dose cyclophosphamide chemotherapy and autologous hematopoietic stem cell transplantation for relapsed lymphoma. The patient exhibited tachycardia, tachypnea, and hypotension, but other findings in the physical examination were unremarkable. The imaging studies showed no evidence of pulmonary embolism, but multiple ground-glass opacities and bilateral pleural effusions were observed on chest high-resolution computed tomography scans. In the right heart catheterization study, the mean pulmonary artery pressure and pulmonary vascular resistance were 35 mm Hg and 5.93 Wood units, respectively, with a normal pulmonary capillary wedge pressure of 10 mm Hg. Pulmonary function tests revealed a remarkable reduction in the percentage predicted value of diffusing capacity of the lungs for carbon monoxide to 31%. Lymphoma progression, collagen diseases, infectious diseases such as human immunodeficiency virus or parasitic infections, portal hypertension, and congenital heart disease were carefully excluded as these are also capable of causing pulmonary arterial hypertension. Thereafter, we reached a final diagnosis of PVOD. The patient was treated with supplemental oxygen and a diuretic during 1 month of hospitalization, which relieved her right heart overload symptoms. Herein, we present the patient's clinical course and diagnostic workup because misdiagnosis or inappropriate treatment can lead to unfavorable outcomes in patients with PVOD.

Bone scan index on bone scintigraphy and radiation therapy for bone metastases from cancers other than prostate and breast cancers: A retrospective observational study.

Objective: In this study, we aimed to use new automatic analysis software (VSBONE bone scan index (BSI); Nihon Medi-Physics, Tokyo, Japan) to investigate whether the pre-radiation therapy (RT) BSI, derived from bone scintigraphy (BS) images, is a prognostic indicator in patients undergoing RT for bone metastases from cancers other than breast or prostate cancer. Materials and Methods: In this retrospective single-institution study, we analyzed data of 51 patients who had undergone whole-body scintigraphy before receiving RT for bone metastases from cancers other than breast and prostate cancer between 2013 and 2019. Their bone metastases preradiation BSI were automatically calculated using newly developed software (VSBONE BSI; Nihon Medi-Physics, Tokyo, Japan). Univariate and multivariate analyses were performed to identify associations between selected clinical variables and overall survival (OS). Results: We did not find a significant association between BSI and OS. However, we did find that younger patients had significantly better OS than older patients (P = 0.016 and P = 0.036, respectively). In addition, BSI were significantly lower in patient with solitary or osteolytic bone metastases than in those with osteoblastic or mixed bone metastases (P = 0.035 and P ≤ 0.001, respectively), and significantly higher in those with lung cancer than in those with other types of cancer (mean BSI 3.26% vs. 1.97%; P = 0.009). Conclusion: The only significant association with survival identified in this study was for age at the time of BS and at time of diagnosis of bone metastases.

Coronavirus disease 2019 (COVID-19) in patients before, during, or after lung irradiation, and serum SP-A and SP-D levels.

BACKGROUND: The correlation between COVID-19 and RT has not been determined to date and remains a clinical question. The aim of this study was to evaluate coronavirus disease 2019 (COVID-19) pneumonia before, during, and after radiation therapy (RT) regarding the radiation doses, radiation pneumonitis, and surfactant protein levels. METHODS: We evaluated patients diagnosed with COVID-19 before, during, or after RT for the lung between August 2020 and April 2022. In patients with breast cancer, the RT dose to the ipsilateral lung was determined. In all other patients, bilateral lung RT doses were determined. Patients diagnosed with COVID-19 after RT were evaluated to determine whether radiation pneumonitis had worsened compared with before RT. The serum levels of the surfactant proteins SP-A and SP-D were measured before, during, and after RT. RESULTS: The patients included in the study comprised three men (27.3%) and eight women (72.7%). The primary cancer sites were the breast (n = 7; 63.7%), lung (n = 2; 18.1%), esophagus (n = 1; 9.1%), and tongue (9.1%). COVID-19 was diagnosed before RT in four patients, during RT in two patients, and after RT in five patients. Six (54.5%) patients developed COVID-19 pneumonia. Radiation pneumonitis grade ≥2 was not identified in any patient, and radiation pneumonitis did not worsen after RT in any patient. No rapid increases or decreases in SP-A and SP-D levels occurred after the diagnosis of COVID-19 in all patients regardless of RT timing. CONCLUSIONS: COVID-19 did not appear to result in lung toxicity and surfactant protein levels did not change dramatically.

Bladder filling volume variation between the first and second day of planning computed tomography for prostate cancer radiation therapy and correlation with renal function.

AIM: During radiation therapy (RT) for prostate cancer, bladder filling helps exclude the organ from irradiation and reduces adverse effects. For RT planning, we performed computed tomography (CT) for 2 consecutive days to evaluate inter-day variations in organs such as the bladder. However, the patient factors that are associated with large intra-patient variations in bladder filling volume prior to RT are not known. METHODS: This was a retrospective study of 97 prostate cancer patients who underwent CT for 2 consecutive days for RT planning between March 2015 and March 2020 and with confirmed water intake volume before the scans. Patients consumed 500 ml of water immediately after urination and underwent CT 30 min after the start of water intake; CT was performed under similar conditions over 2 consecutive days. Patient information was collected from the medical records taken before CT. RESULTS: The median bladder filling volume was 102.8 cm3 (range: 31.7-774.0), and the median intra-patient bladder filling volume variation was 23.4 cm3 (range: 0.4-277.7). Univariate analysis revealed that the intra-patient variation was significantly larger in patients with an eGFR higher than the median (p = 0.003). No other factor showed correlations with the variation. As the larger bladder filling volume of the 2 consecutive days in patients increased (median 121.5 cm3 , range: 47.8-774.0), the intra-patient variation also increased. CONCLUSION: Patients with a higher eGFR show greater variation in bladder filling volume, and caution should be exercised when applying RT in these patients.

Radiation therapy for pelvic recurrent colorectal or gynecological cancer: is whole pelvic irradiation necessary?

BACKGROUND: Preoperative whole pelvic radiation therapy (RT) is used commonly for rectal cancer and is the standard field postoperatively in gynecological cancer. However, the ideal field (local vs. whole pelvis) has not been determined for local recurrence of these cancers. METHODS: We retrospectively reviewed the data for 52 patients who developed local tumor recurrence of rectal or gynecological cancer treated from 2013 to 2021. The initial treatment for all patients was total excision of the primary tumors without radiation therapy. Radiation therapy targets were surgical stumps, perianastomosis sites, and pelvic lymph nodes, classified according to the pelvic nodal volume atlas for radiation therapy. Patients were divided into the local recurrent tumor only radiation therapy group and the whole pelvis radiation therapy group. Whole pelvis radiation therapy included the common iliac lymph nodes or prophylactic lymph nodes below the L5/S1 junction. We recorded second recurrence after RT and the affected site(s) in each group. We also compared disease-specific survival using uni- and multivariate analyses. RESULTS: We found no significant differences between the groups regarding second recurrence or regarding the site(s) of recurrence. We also found no significant differences in disease-specific survival between the two RT groups. However, patients who did not receive chemotherapy after the initial surgery and before RT had significantly longer survival (P=0.015). CONCLUSIONS: In patients with locally recurrent rectal or gynecological cancer, we found no significant difference in second recurrence or survival between the local tumor only RT field and the whole pelvic RT field.

The clinical course in pediatric solid tumor patients with focal nodular hyperplasia of the liver.

BACKGROUND: Focal nodular hyperplasia (FNH) of the liver is a rare benign lesion that may be related to the vascular and hepatic damage induced by completion of tumor therapy and a reaction to localized vascular abnormality. The aim of this study was to analyze the clinical course in pediatric solid tumor patients with FNH. METHODS: We analyzed thirty-two patients with pediatric solid tumors who received multiagent chemotherapy (15 advanced neuroblastomas, 7 hepatoblastomas, 5 rhabdomyosarcomas, 2 nephroblastomas, 1 rhabdoid tumor of the kidney, 1 clear cell sarcoma of the kidney and 1 pancreatoblastoma). All of them had been previously treated at our hospital, and have been alive for over 3 years without recurrence. RESULTS: FNH lesions were discovered in three (9.4%) of 32 patients, and were neuroblastoma (NB) stage 4. All 3 patients received induction chemotherapy and high-dose alkylating agents, and developed grade 3 (National Cancer Institute Common Toxicity Criteria; NCI-CTC) liver dysfunction during completion of tumor therapy without veno-occlusive disease. Two of the 3 patients received the same induction chemotherapy and high doses of alkylating agents with total body irradiation for cytoreductive agents prior to peripheral blood cell transplantation. FNH lesions in both female patients who received estrogen replacement therapy after completion of tumor therapy have expanded and are increasing. CONCLUSION: FNH appears to be a late complication of iatrogenic disease in NB stage 4 patients. The therapeutic agents for NB stage 4 and estrogen replacement therapy should be considered as risk factors for the development of FNH.

Isolated tuberculous liver abscess invading the abdominal wall: report of a case.

Isolated tuberculous liver parenchymal and subcapsular abscesses are unusual,^but an abdominal wall abscess secondary to a tubercular liver abscess is extremely rare. To our knowledge, there is only one reported case of an abdominal wall abscess occurring secondary to a subcapsular liver abscess. We report the first documented case of direct invasion of the abdominal wall from an isolated tuberculous liver parenchymal abscess, diagnosed by imaging, surgical, and pathological findings. Although ultrasonography and computed tomography showed nonspecific hypoechoic and hypodense findings with peripheral contrast enhancement, T2-weighted magnetic resonance imaging (MRI) revealed a heterogeneous mass with characteristic hypointensity, suggesting the presence of free radicals produced by macrophages during active phagocytosis in tuberculosis. Although our case is extremely unusual, when hypointensity on T2-weighted MRI is seen, the possibility of tuberculosis should be considered and the results of polymerase chain reaction, culture, and histopathological diagnosis must be taken into account to avoid needless invasive surgery.

Data management solution for large-volume computed tomography in an existing picture archiving and communication system (PACS).

Multidetector row computed tomography (MDCT) creates massive amounts of data, which can overload a picture archiving and communication system (PACS). To solve this problem, we designed a new data storage and image interpretation system in an existing PACS. Two MDCT image datasets, a thick- and a thin-section dataset, and a single-detector CT thick-section dataset were reconstructed. The thin-section dataset was archived in existing PACS disk space reserved for temporary storage, and the system overwrote the source data to preserve available disk space. The thick-section datasets were archived permanently. Multiplanar reformation (MPR) images were reconstructed from the stored thin-section datasets on the PACS workstation. In regular interpretations by eight radiologists during the same week, the volume of images and the times taken for interpretation of thick-section images with (246 CT examinations) or without (170 CT examinations) thin-section images were recorded, and the diagnostic usefulness of the thin-section images was evaluated. Thin-section datasets and MPR images were used in 79% and 18% of cases, respectively. The radiologists' assessments of this system were useful, though the volume of images and times taken to archive, retrieve, and interpret thick-section images together with thin-section images were significantly greater than the times taken without thin-section images. The limitations were compensated for by the usefulness of thin-section images. This data storage and image interpretation system improves the storage and availability of the thin-section datasets of MDCT and can prevent overloading problems in an existing PACS for the moment.

Association between unintentional splenic radiation and lymphopenia and high neutrophil/lymphocyte ratio after radiotherapy in patients with esophageal cancer.

BACKGROUND: Unintentional irradiation of the spleen may reduce absolute lymphocyte count (ALC), which can affect tumor immunity. Therefore, in the present study, we evaluated spleen dose-volume parameters associated with ALC and neutrophil/lymphocyte ratio (NLR) in patients with esophageal cancer. METHODS: This retrospective study evaluated patients who were diagnosed with stage I-IV esophageal cancer and who received radiotherapy at Nihon University Itabashi Hospital between January 2015 and March 2020. Spleen V5, V10, V20, and V30 and mean spleen dose, which are dose-volume histogram parameters correlated with ALC and NLR, were analyzed. RESULTS: In total, 89 esophageal cancer patients with a median age of 72 years (range, 51-92 years) were included in this research. Results showed that spleen V5, V10, and V20 and mean splenic dose were significantly correlated with a low ALC. Meanwhile, a significant association was observed between spleen V5 and V10 and a high NLR (P<0.05). In the linear regression analysis, spleen V5 and V10 were remarkably associated with a low ALC (P=0.006 and 0.008). Further, a correlation was noted between spleen V5 and a high NLR (P=0.019). Spleen V5 and V10 were remarkably associated with greater than grade 3 lymphopenia (P=0.024 and P=0.031). CONCLUSIONS: A correlation was observed between the irradiated volume of the spleen and ALC and NLR in patients with esophageal cancer. Furthermore, the spleen should be regarded as a high-risk organ, and the use of techniques in reducing spleen V5, V10 for the preservation of tumor immunity may be beneficial.