Unreduced spore formation in a spontaneous chimeric pinnule in an artificially produced haploid Anisocampium niponicum (Athyriaceae, Polypodiales).

Haploid sporophytes of Anisocampium niponicum with 2n = 40, were produced artificially by induced apogamy in vitro. They were subsequently transplanted into pots and two of them have been cultivated for the investigation of sporogenesis and/or production of chimera for more than 20 years. Haploid A. niponicum is sterile, but an abnormal chimeric pinnule that developed spontaneously in a single frond produced sporangia with spores. Each sporangium bore approximately 32 spores that were almost uniform in size. Sowing of these spores resulted in 50 gametophytes. Of 20 gametophytes cultured individually, five produced sporophytes apogamously after eight months. Both the gametophytes and subsequent apogamous sporophytes showed a chromosome number of 2n = 40. Our study demonstrates that a haploid sporophyte offspring can be produced from a haploid mother sporophyte via haploid spores. Since asexual reproduction is a prominent evolutionary process in ferns, the reproduction of a haploid A. niponicum sporophyte by unreduced spore formation might help to elucidate how apogamous ferns occur and evolve.

Daily irradiation versus irradiation at two- to three-day intervals in stereotactic radiotherapy for patients with 1-5 brain metastases: study protocol for a multicenter open-label randomized phase II trial.

BACKGROUND: Radiobiological daily changes within tumors are considered to be quite different between stereotactic radiotherapy (SRT) (e.g., 50 Gy in 4 fractions) and conventional radiotherapy (e.g., 60 Gy in 30 fractions). We aim to assess the optimal interval of irradiation in SRT and compare outcomes of daily irradiation with irradiation at two- to three-day intervals in SRT for patients with one to five brain metastases (BM). METHODS: This study is conducted as a multicenter open-label randomized phase II trial. Patients aged 20 or older with one to five BM, less than 3.0 cm diameter, and Karnofsky Performance Status ≥70 are eligible. A total of 70 eligible patients will be enrolled. After stratifying by the number of BMs (1, 2 vs. 3-5) and diameter of the largest tumor (< 2 cm vs. ≥ 2 cm), we randomly assigned patients (1:1) to receive daily irradiation (Arm 1), or irradiation at two- to three-day intervals (Arm 2). Both arms are performed with total dose of 27-30 Gy in 3 fractions. The primary endpoint is an intracranial local control rate, defined as intracranial local control at initially treated sites. We use a randomized phase II screening design with a two-sided α of 0∙20. The phase II trial is positive with p < 0.20. All analyses are intention to treat. This study is registered with the UMIN-clinical trials registry, number UMIN000048728. DISCUSSION: This study will provide an assessment of the impact of SRT interval on local control, survival, and toxicity for patients with 1-5 BM. The trial is ongoing and is recruiting now. TRIAL REGISTRATION: UMIN000048728. Date of registration: August 23, 2022. https://center6.umin.ac.jp/cgi-bin/ctr/ctr_view_reg.cgi?recptno=R000055515 .

A retrospective study of definitive chemoradiotherapy in patients with resectable small cell neuroendocrine carcinoma of the esophagus.

BACKGROUND: Standard treatment for resectable small cell neuroendocrine carcinoma of the esophagus (SCNEC-E) remains to be established. METHODS: We retrospectively studied 7 consecutive patients with resectable SCNEC-E who received definitive chemoradiotherapy (dCRT) to evaluate the safety and efficacy. Treatment consisted of two courses of chemotherapy with cisplatin (80 mg/m2 on day 1) and etoposide (100 mg/m2 on days 1-3) or carboplatin (AUC 5 on day 1) and etoposide (80 mg/m2 on days 1-3) given every 4 weeks during dCRT. The total radiation dose was 50.4 Gy (28 fractions). RESULTS: The clinical stage was IA in 1 patient, IB in 2 patients, IIA in 3 patients, and IIB in 1 patient. Definitive CRT was completed in all patients. The median overall treatment time of radiotherapy was 44 days. The chemotherapy regimen included in dCRT was cisplatin and etoposide in 3 patients and carboplatin and etoposide in 4 patients. Acute adverse events of grade 3 or 4 were neutropenia 100%, thrombocytopenia 43%, febrile neutropenia 43%, and nausea 14%. There were no late grade 3 or 4 adverse events. The median survival time was 32 months. The complete response rate was 100%. The recurrence rate was 43%. The median survival of the 4 patients without recurrence was 56 months. CONCLUSIONS: Definitive CRT with cisplatin and etoposide or carboplatin and etoposide is a feasible treatment for the resectable SCNEC-E, and long-term survival can be achieved in some patients.

Long-term outcomes of combining prostate brachytherapy and metastasis-directed radiotherapy in newly diagnosed oligometastatic prostate cancer: A retrospective cohort study.

BACKGROUND: Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy (STAMPEDE) trial showed the survival benefit for prostate radiotherapy in newly diagnosed prostate cancer patients with a low metastatic burden. The result raises the next question whether additional radiotherapy to metastatic sites could improve the survival in those with a low metastatic burden. METHODS: We evaluated the efficacy and safety of prostate-directed radiotherapy (PDRT) with or without metastasis-directed radiotherapy (MDRT) in newly diagnosed oligometastatic patients who underwent combination of high-dose-rate prostate brachytherapy, external beam radiotherapy, and androgen deprivation therapy. Forty patients with bone metastasis and node positive prostate cancer were retrospectively analyzed. Of these, 22 (55%), 3 (7%), and 15 (38%) patients had N1M0, M1a, and M1b, respectively. Eighteen patients (45%) received MDRT to all metastatic sites. All patients initially underwent ≧6 months of androgen deprivation therapy. Oligometastatic disease was defined as presence of five or fewer metastatic lesions. Median follow-up period was 62.5 months. RESULTS: Of the 40 patients, the 5-year castration-resistant prostate cancer (CRPC)-free survival rate and cancer-specific survival was 64.4% and 87.9%, respectively. Pre- or post-treatment predictive value including prostate-specific antigen (PSA) at diagnosis ≥20 ng/mL, Gleason grade group 5, positive biopsy core rate ≥51%, PSA nadir level of ≥0.02 ng/mL after the radiotherapy, and no MDRT were significantly associated with progression to CRPC. Patients with MDRT had significantly higher probability of achieving a PSA level of <0.02 ng/mL than those without the therapy (88.8% vs 54.5%, P = 0.0354) and consequently had a better CRPC-free survival than those without the therapy (HR 0.319, 95%CI: 0.116-0.877). Comparing PDRT alone, PDRT with MDRT did not significantly increase the incidences of genitourinary and gastrointestinal toxicities. CONCLUSIONS: This single-institutional study revealed the feasibility of combining prostate brachytherapy and MDRT for newly diagnosed oligometastatic prostate cancer. This combined approach has potential to prolong CRPC-free survival.

Clinical outcomes of 849 laryngeal cancers treated in the past 40 years: are we succeeding?

OBJECTIVE: We analyzed the clinical outcomes of 849 laryngeal cancers treated in the past 40 years, which overlapped with the era of the global treatment shift. METHODS: To compare the chronological outcomes, patients were divided into four groups according to their registration year as 1972-82, 1983-92, 1993-2002 and 2003-12; treatment trends, larynx preservation rate and overall survival rate were compared. RESULTS: There were 104, 173, 253 and 319 patients registered in 1972-82, 1983-92, 1993-2002 and 2003-12, respectively. Five-year overall survival rates were 74, 76.5, 75.6 and 82.2% in 1972-82, 1983-92, 1993-2002 and 2003-12, respectively. The five-year larynx preservation rates were 65.5, 75.7, 75.4 and 80.9% in 1972-82, 1983-92, 1993-2002 and 2003-12, respectively. CONCLUSIONS: The number of patients treated at our institute increased, and the overall survival and larynx preservation rates exhibited favorable improvements over the past four decades. In the analysis of nonsurgical options, S1 combined radiotherapy showed superiority over concurrent chemoradiotherapy and radiotherapy in larynx preservation, and S1 combined radiotherapy, concurrent chemoradiotherapy and Tegafur Uracil combined radiotherapy showed superiority over radiotherapy in overall survival. In nonsurgical approaches, proper case selection is the key to success and may be much more important than pursuing radiotherapy dose escalation. In the analysis of surgical options, laser and supracricoid laryngectomy with cricohyoidoepiglottopexy contributed to larynx preservation in early- and intermediate-stage cancers, respectively. Supracricoid laryngectomy with cricohyoidoepiglottopexy demonstrated overall survival not worse than total laryngectomy, which is the prerequisite treatment basis for larynx preservation options. We must make extra efforts in pursuing an ideal balance between nonsurgical and surgical larynx preservation options.

Optimizing Organ-Preservation Strategies Through Chemotherapy-Based Selection in Esophageal Squamous Cell Carcinoma: Results From the CROC Multi-Institutional Phase 2 Clinical Trial.

PURPOSE: This study aimed to assess the viability of definitive chemoradiotherapy (dCRT) as an organ-preservation strategy for remarkable responders who were downstaged to stage IA after receiving induction chemotherapy for resectable esophageal squamous cell carcinoma (ESCC). METHODS AND MATERIALS: Chemotherapy-naïve patients with resectable ESCC (stage IB-III, Union for International Cancer Control, International Cancer Control seventh edition) were eligible for the study. All patients received 3 cycles of docetaxel, cisplatin, and 5-FU (DCF) therapy (docetaxel 75 mg/m2 on day 1, cisplatin 75 mg/m2 on day 1, and 5-fluorouracil [5-FU] 750 mg/m2 on days 1-5, repeated every 3 weeks). Remarkable response was defined as a reduction in the tumor to T1, metastatic lymph nodes <1 cm on the short axis, and downstaging to stage IA after 3 cycles of DCF therapy. Remarkable responders then underwent dCRT, which included 2 courses of cisplatin 75 mg/m2 and 5-FU 1000 mg/m2 on days 1 to 4, repeated every 4 weeks, along with 50.4 Gy of concurrent radiation therapy. The primary endpoint was 1-year progression-free survival in remarkable responders following DCF therapy and subsequent dCRT. Secondary endpoints included 3-year overall survival (OS) and esophagectomy-free survival. RESULTS: Of the 92 patients registered, 90 were analyzed. A remarkable response to 3 courses of DCF therapy was observed in 58.4% of patients. Among these responders, 89.8% achieved a complete response after dCRT. During the median follow-up period of 33 months (range, 1-85 months), the 1-year progression-free survival was 89.8% (95% confidence interval [CI], 77.2%-95.6%, primary endpoint), and the 3-year OS was 83.7%. The 3-year OS and esophagectomy-free survival rates in the analysis group were 74.1% and 45.3%, respectively. An 18F-fluorodeoxyglucose-positron emission tomography response after 2 courses of DCF therapy was significantly associated with OS (P = .0049). CONCLUSIONS: In patients with resectable ESCC, dCRT for remarkable responders downstaging to stage IA after induction chemotherapy with 3 courses of DCF therapy is a feasible treatment option and provides an optimizing organ-preservation strategy of chemotherapy-based selection.

Dosimetric Predictors of Toxicity after Prostate Stereotactic Body Radiotherapy: A Single-Institutional Experience of 145 Patients.

The indications for stereotactic body radiotherapy (SBRT) for prostate cancer have increased. However, the relationships between adverse events and risk factors remain unclear. This study aimed to clarify associations between adverse events and dose index for prostate SBRT. Participants comprised 145 patients irradiated with 32-36 Gy in 4 fractions. Radiotherapy-related risk factors such as dose-volume histogram parameters and patient-related risk factors such as T stage and Gleason score were evaluated in a competing risk analysis. Median follow-up duration was 42.9 months. A total of 9.7% had acute Grade ≥ 2 GU toxicities and 4.8% had acute Grade ≥ 2 GI toxicities. A total of 11.1% had late Grade ≥ 2 GU toxicities and 7.6% had late Grade ≥ 2 GI toxicities. Two (1.4%) patients suffered from late Grade 3 GU toxicities. Similarly, two (1.4%) patients suffered from late Grade 3 GI toxicities. Acute GU and GI events correlated with prostate volume and dose to the hottest 10 cc volume (D10cc)/volumes receiving a minimum of 30 Gy (V30 Gy) of rectum, respectively. Late GI toxicity, frequency, and rectal hemorrhage correlated with rectal D0.1 cc/D1 cc, maximum dose to the bladder, and rectal D0.1 cc, respectively. Toxicities after prostate SBRT using 32-36 Gy/4 fractions were acceptable. Our analysis showed that acute toxicities correlated with volume receiving a medium dose level, and late toxicities correlated with highest point dose of organs at risk.

Quality of life score as a prognosticator for pharyngeal cancer patients treated with radiotherapy.

The purpose of this study was to evaluate the prognostic value of quality of life (QOL) scores acquired not only pre-treatment, but also 1 month after treatment for locoregional control (LRC), distant metastasis-free survival (DMFS), and overall survival (OS) in patients with pharyngeal cancer treated using radiotherapy. Data for 102 patients with naso-, oro-, or hypo-pharyngeal cancer treated between December 2008 and September 2017 were retrospectively analyzed. About 90% of the patients were male. The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) was used for QOL assessments. Associations between QLQ-C30 scores before and 1 month after treatment and outcomes including LRC, DMFS, and OS were analyzed using Cox proportional hazard models. Median follow-up was 37 months (range, 5-117 months). Three-year LRC, DMFS, and OS rates were 77.8%, 60.0%, and 66.5%, respectively. Pre-treatment emotional functioning and diarrhea at 1 month after treatment were identified as significant predictors of LRC. Pre-treatment global QOL and diarrhea at 1 month after treatment were detected as significant predictors of DMFS. Pre-treatment emotional functioning, pre-treatment appetite loss, and diarrhea at 1 month after treatment were detected as significant predictors of OS. Diarrhea at 1 month after treatment was the most powerful QOL variable for predicting LRC, DMFS and OS. Our study revealed that several QOL scores not only before treatment but also 1 month after treatment correlated with LRC, DMFS and OS. In particular, the diarrhea domain of QOL at 1 month after treatment offered the most powerful prognosticator for pharyngeal cancer patients treated with radiotherapy.

Reticulate evolution of the hybrid produced artificially by crosses between Osmunda banksiifolia and Osmunda lancea.

Although ferns have been developed by hybridization and chromosome doubling, no natural polyploidy has yet been recorded in Osmundaceae. So, we produced hybrids artificially by crosses between Osmunda banksiifolia (2n = 2x = 44) and Osmunda lancea (2n = 2x = 44), and investigated their sporogenesis. From the O. banksiifolia x O. lancea hybrid with 44 univalent chromosomes, allotetraploids with 44 bivalent chromosomes were produced by chromosome doubling, and allotriploids with 22 univalent chromosomes and 22 bivalent chromosomes were then produced by back crosses. The results show when and how chromosome doubling occurs in hybrids. The success of artificial hybridization between O. banksiifolia and O. lancea, did not, however, reflect any product of natural hybridization between the two species.

Size of pelvic bone metastasis as a significant prognostic factor for metastatic prostate cancer patients.

INTRODUCTION: To investigate the potential prognostic value of image analysis of pelvic bone metastasis in newly diagnosed prostate cancer patients. METHODS: Data from 69 patients with both bone scintigraphy and pelvic CT images were selected for this analysis. Open source software (3D Slicer version 4.8.1.) was used for image analysis. Metastatic pelvic bone lesions were manually contoured, and radiomic features were extracted. As risk factors for overall survival (OS) and cause-specific survival (CSS), 105 radiomic features and clinical risk factors including age, initial prostate-specific antigen, Gleason score, TNM stage, lactate dehydrogenase (LDH), hemoglobin (Hb), alkaline phosphatase, extent of disease, visceral metastases, and radiotherapy were assessed by uni- and multivariate analyses. RESULTS: Median follow-up was 41 months (range 0-157 months). Five-year overall survival and cause-specific survival rate were 37.9% and 43.5%, respectively. After multivariate analysis, LDH, Hb, and "maximum 2D diameter" defined as maximum tumor size in the axial plane were detected as risk factors for OS. Gleason sum, LDH, and maximum 2D diameter were detected as risk factors for CSS. CONCLUSION: Maximum 2D diameter was detected as a significant prognostic factor for metastatic prostate cancer patients.

Multiple gastrointestinal metastasis after endoscopic submucosal dissection for poorly differentiated gastric adenocarcinoma.

A 76-year-old man had a diagnosis of double primary cancers consisting of poorly differentiated esophageal squamous cell carcinoma (ESCC) invading the submucosa and poorly differentiated gastric adenocarcinoma (GAC) invading the submucosa. The clinical stage of both ESCC and GAC was T1N0M0 stage I. The tumor diameter of ESCC and GAC was 20 mm and 25 mm, respectively. We performed chemoradiotherapy for ESCC. Chemotherapy consisted of nedaplatin in an intravenous dose of 90 mg/m2 on day 1 and 5-fluorouracil in an intravenous dose of 800 mg/m2 on days 1-5, repeated every 4 weeks for two cycles. Radiotherapy consisted of 50.4 Gy in 28 fractions for ESCC. GAC was down-staged after chemoradiotherapy for ESCC and was treated by endoscopic submucosal dissection (ESD). The tumor was histopathologically confirmed to be down-staged to intramucosal cancer with a diameter of 18 mm and no evidence of lymphovascular invasion and ulceration. Multiple metastasis occurred in the stomach, the small intestine and the colorectum after ESD. ESD is not a curative treatment even if chemotherapy is effective for poorly differentiated GAC invading the submucosa. Multiple gastrointestinal metastasis may be a unique recurrence pattern after ESD for such a lesion.

Dosimetric factors associated with long-term patient-reported outcomes after definitive radiotherapy of patients with head and neck cancer.

BACKGROUND: The aim of this study was to explore the relationships between dosimetric parameters of organs at risk and patient-reported outcomes (PRO) after radiotherapy of patients with head and neck cancer. METHODS: PRO data of 53 patients with head and neck cancer treated with radiotherapy were prospectively collected. These data concerned health-related quality of life (HRQOL) and were collected using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ-C30) and head and neck cancer module (QLQ-H&N35). Patients were divided into "severe-deterioration" and "mild-deterioration" groups on the basis of degree of deterioration HRQOL > 6 months after completing treatment. The relationships between HRQOL deteriorations and patient-related or dosimetry-related factors were evaluated. P < 0.0013 according to Bonferroni correction was considered to denote statistical significance. RESULTS: Regarding "trouble with social eating (HNSO)" and "coughing (HNCO)," there were significant differences between the severe-deterioration and mild-deterioration groups in mean dosages to the superior pharyngeal constrictor muscle (SPC) (HNSO: 62.5 Gy vs 54.2 Gy; p = 0.00029, and HNCO: 61.5 Gy vs 54.1 Gy; p = 0.0012) and parotid gland (HNSO: 24.1 Gy vs 20.5 Gy; p = 0.000056, and HNCO: 24.2 Gy vs 20.3 Gy; p = 0.00043). Regarding "nausea and vomiting," there was a significant difference between the two groups in the mean dosage to the middle pharyngeal constrictor muscle (MPC: 61.9 Gy vs. 58.4Gy; P = 0.00059). CONCLUSIONS: We found that dosages to the SPC and parotid gland were associated with severe deterioration in HRQOL attributable to difficulty in HNSO and HNCO, whereas dosage to the MPC was associated with severe deterioration attributable to nausea and vomiting.

A phase I dose-escalation trial of stereotactic body radiotherapy using 4 fractions for patients with localized prostate cancer.

PURPOSE: To report results from our phase I dose-escalation study of stereotactic body radiotherapy (SBRT) using 4 fractions for patients with localized prostate cancer. MATERIALS & METHODS: Fraction sizes of 8 Gy, 8.5 Gy, and 9 Gy were defined as levels 1, 2, and 3. The prescribed dose was delivered to at least 95% of the planning target volume. Image-guided, intensity-modulated radiotherapy was delivered to all patients. Dose-limiting toxicity (DLT) was defined as acute toxicity of Grade 3 or higher. The maximum tolerated dose (MTD) was defined as the level at which ≥30% of patients showed DLT. The recommended dose (RD) was defined to be one dose level below the MTD. If no patients at level 3 showed DLT, level 3 was defined as the recommended dose (RD). RESULTS: Nine patients were enrolled in each level. All patients were low or intermediate risk. Median durations of follow-up for patients at levels 1-3 were 48.9 months, 42.6 months, and 18.4 months, respectively. Protocol treatment was completed for all patients. No patient showed DLT at each dose level. Level 3 was therefore designated as the RD for the phase II study. Although most toxicities were Grade 1, genitourinary toxicity was common compared to gastrointestinal toxicity. Three-year biochemical control rate was 90.3%. CONCLUSION: The dose level of 36 Gy in 4 fractions with a 2-day break was tolerable and highly encouraging for SBRT of localized prostate cancer. The phase II trial to confirm the efficacy and toxicity of this treatment is now on going. TRIAL REGISTRATION: UMIN, UMIN000010236 . Registered 13 March 2013.

A cold spot compensation technique using a combination of trans-rectal ultrasonography and intraoperative computed tomography for interstitial permanent prostate brachytherapy: a single-arm prospective trial.

PURPOSE: To evaluate the efficacy of a cold spot compensation technique using a combination of trans-rectal ultrasonography (TRUS) and computed tomography (CT) for permanent interstitial prostate brachytherapy. MATERIAL AND METHODS: Sixty-five patients were treated with the cold spot compensation technique using TRUS-CT fusion. The prescribed dose was set at 145 Gy. The dose to 90% of prostate volume (D90) was planned to be within 195 Gy (134%) and 205 Gy (141%). After implantation using the conventional technique, additional seeds were implanted if cold spots were detected on TRUS-CT fusion images. RESULTS: Cold spots were detected in 32 of 65 patients (49%) and were compensated by additional seeds. Median number of additional seeds was 3 (range, 1-5). A CT scan 1 month later revealed that the percentage of patients receiving an undesirably low D90 (160-180 Gy) was significantly reduced in the examination arm compared to historical controls. However, mean operation time was significantly longer in the examination arm (64 min) than in historical controls (49 min, p < 0.001). With median follow-up of 18 months (range, 9-24 months), no grade 3 or worse toxicity was encountered. CONCLUSION: The cold spot compensation technique using TRUS-CT fusion appears effective for patients receiving permanent interstitial prostate brachytherapy.

Comparison of prostate contours between conventional stepping transverse imaging and Twister-based sagittal imaging in permanent interstitial prostate brachytherapy.

PURPOSE: To compare prostate contours on conventional stepping transverse image acquisitions with those on twister-based sagittal image acquisitions. MATERIAL AND METHODS: Twenty prostate cancer patients who were planned to have permanent interstitial prostate brachytherapy were prospectively accrued. A transrectal ultrasonography probe was inserted, with the patient in lithotomy position. Transverse images were obtained with stepping movement of the transverse transducer. In the same patient, sagittal images were also obtained through rotation of the sagittal transducer using the "Twister" mode. The differences of prostate size among the two types of image acquisitions were compared. The relationships among the difference of the two types of image acquisitions, dose-volume histogram (DVH) parameters on the post-implant computed tomography (CT) analysis, as well as other factors were analyzed. RESULTS: The sagittal image acquisitions showed a larger prostate size compared to the transverse image acquisitions especially in the anterior-posterior (AP) direction (p < 0.05). Interestingly, relative size of prostate apex in AP direction in sagittal image acquisitions compared to that in transverse image acquisitions was correlated to DVH parameters such as D90 (R = 0.518, p = 0.019), and V100 (R = 0.598, p = 0.005). CONCLUSIONS: There were small but significant differences in the prostate contours between the transverse and the sagittal planning image acquisitions. Furthermore, our study suggested that the differences between the two types of image acquisitions might correlated to dosimetric results on CT analysis.

Variability of treatment planning of seed implantation: A Japanese multicenter simulation study.

PURPOSE: This multicenter study was conducted to evaluate the current variability of treatment planning of seed implantation in Japanese centers and the feasibility of two virtual trials. METHODS AND MATERIALS: Two types of contour data were sent to 12 radiation oncologists with a request letter that asked them to make treatment plans on the data in the same manner as in their own practice. Five of the 12 radiation oncologists were asked to participate in the two virtual trials in which the D90 (dose to the hottest 90% of prostate volume) was 1) required to be set at just 180 Gy and 2) increased as much as possible without violating other limitations. RESULTS: A relatively high dose with a small deviation was irradiated to the prostate in Japanese centers (mean D90 = 188 Gy; SD = 10 Gy). In the virtual trials, all five physicians could achieve 180 Gy for the D90 with a very small deviation, although the urethral dose showed relatively large deviations. Dose escalation without increase of urethral dose or V150 was difficult, although the rectum could be spared by most of the physicians. CONCLUSION: Our study showed a relatively high dose with a small deviation was prescribed to the prostate in Japanese centers. Consolidated protocols such as D90 = 180 Gy could be available for future trials. Meanwhile, our study suggested that some cautions might be needed for urethral dose and the V150, even when a relatively low D90 was requested.

Dosimetry of permanent interstitial prostate brachytherapy for an interoperative procedure, using O-arm based CT and TRUS.

PURPOSE: The aim of this report is dosimetric evaluation for an intraoperative fusion computed tomography (CT) as a superior predictor of 1-month CT based dosimetry in comparison to transrectal ultrasound (TRUS) in permanent interstitial prostate brachytherapy. MATERIAL AND METHODS: Data of 65 patients treated with seed implantation were analyzed. All procedures has been performed with patients in the lithotomy position inside the O-arm system. An end-fine probe is used as a landmark to fuse TRUS and O-arm-based CT images. There was no difference in the patient's position, probe position, and timing of image acquisition between the two imaging modalities. Dose-volume histogram (DVH) parameters such as the dose to 90% of prostate volume (D90) has been analyzed. RESULTS: The area under the curve of the receiver operating characteristic tended to be larger on fusion CT than on TRUS for most DVH parameters (71.85% vs. 59.59% for D90; p = 0.07). Significant relationships between fusion CT and 1-month CT were confirmed using Pearson's correlation coefficients for most DVH parameters (R = 0.48, p < 0.01 for D90), although the relationship between TRUS and 1-month CT was poor. Large dose reduction (35 Gy for D90) was seen from TRUS to fusion CT, especially in patients with high body weight and small prostate volume. CONCLUSIONS: Intraoperative fusion CT appears to have higher predictive power for 1-month CT-based dosimetry than TRUS. A prospective trial using fusion CT-based planning is warranted.

Assessment of transposed ovarian movement: how much of a safety margin should be added during pelvic radiotherapy?

The purpose of this study was to analyze transposed ovarian movement. Data from 27 patients who underwent ovarian transposition after surgical treatment for uterine cancer were retrospectively analyzed. Computed tomography (CT) images including transposed ovaries were superimposed on other CT images acquired at different times, and were matched on bony structures. Differences in ovarian position between the CT images were measured. The planning organ at risk volume (PRV) margins were calculated from the formula of the 90% reference intervals (RIs) and the 95% RI, which were defined as mean ± 1.65 standard deviation (SD) and mean ± 1.96 SD, respectively. The 90% RI in the cranial, caudal, anterior, posterior, left and right directions were 1.5, 1.5, 1.4, 1.0, 1.7 and 0.9 cm, respectively. The 95% RI in the corresponding directions were 1.5, 2.0, 1.7, 1.2, 1.9 and 1.2 cm, respectively. These data suggest that bilateral ovaries need a PRV margin of ∼2 cm in all directions. The present study suggests that a transposed ovary needs the same PRV margin as a normal ovary (∼2 cm). Even after transposition, ovaries should be kept away from the radiation field to take into consideration the degree of ovarian movement.

Comparison of three different techniques of low-dose-rate seed implantation for prostate cancer.

PURPOSE: Three different techniques of low-dose-rate seed implantation for prostate cancer have been used since its use started in our hospital. The purpose of this study was to compare the results of the three different techniques. MATERIAL AND METHODS: The data of 305 prostate cancer patients who underwent low-dose-rate seed implantation were retrospectively analyzed. Pre-plan technique (n = 27), intraoperative pre-plan technique (n = 86), and interactive plan technique (n = 192) were tried in chronological order. The prescribed dose was set at 145 Gy. RESULTS: Median follow-up was 66 months (range: 12-94 months). The 5-year biochemical control rate was 95.5% (pre-plan group: 100%, intraoperative pre-plan group: 90.7%, interactive plan group: 97.0%; p = 0.08). Dosimetric parameters were generally increased from the pre-plan group to the interactive group. The differences in some dosimetric parameters between the planning phase and the CT analysis were significantly reduced with the interactive plan compared to the other techniques. The interactive plan showed a significant reduction of the seed migration rate compared to the two other groups. Acute genitourinary toxicity, acute gastrointestinal toxicity, frequency, and urinary retention increased gradually from the pre-plan period to the interactive plan period. CONCLUSIONS: There was no significant difference in biochemical control among the three groups. Dose-volume parameters were increased from the pre-plan technique to the interactive plan technique. However, this may not necessarily be due to technical improvements, since dose escalation was started during the same period. Lower seed migration rates and the smaller differences between the planning phase and CT analysis with the interactive plan technique suggest the superiority of this technique to the two other techniques.