Kotaro Yoshio

Localized Ocular Adnexal Mucosa-Associated Lymphoid Tissue Lymphoma Treated With Radiation Therapy: A Long-Term Outcome in 86 Patients With 104 Treated Eyes

PURPOSE To evaluate the natural history, behavior of progression, prognostic factors, and treatment-related adverse effects of primary ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma (POAML). METHODS AND MATERIALS Eighty-six patients with histologically proven stage I POAML treated with radiation therapy at National Cancer Center Hospital, Tokyo between 1990 and 2010 were retrospectively reviewed. The median age was 56 years (range, 18-85 years). The median dose administered was 30 Gy (range, 30-46 Gy). Seventy-seven patients (90%) were treated by radiation therapy alone. RESULTS The median follow-up duration was 9 years (range, 0.9-22 years). The 5- and 10-year overall survival (OS) rates were 97.6% and 93.5%, respectively, and no patients died of lymphoma. Patients with tumor sizes ≥4 cm showed a greater risk of contralateral relapse (P=.012). Six patients with contralateral relapse were seen and treated by radiation therapy alone, and all the lesions were controlled well, with follow-up times of 3 to 12 years. There was 1 case of local relapse after radiation therapy alone, and 3 cases of relapse occurred in a distant site. Cataracts developed in 36 of the 65 eyes treated without lens shielding and in 12 of the 39 patients with lens shielding (P=.037). CONCLUSIONS The majority of patients with POAML showed behavior consistent with that of localized, indolent diseases. Thirty gray of local irradiation seems to be quite effective. The initial bilateral involvement and contralateral orbital relapses can be also controlled with radiation therapy alone. Lens shielding reduces the risk of cataract.

Vaginal tolerance of CT based image-guided high-dose rate interstitial brachytherapy for gynecological malignancies

BackgroundPurpose of this study was to identify predictors of vaginal ulcer after CT based three-dimensional image-guided high-dose-rate interstitial brachytherapy (HDR-ISBT) for gynecologic malignancies.MethodsRecords were reviewed for 44 female (14 with primary disease and 30 with recurrence) with gynecological malignancies treated with HDR-ISBT with or without external beam radiation therapy. The HDR-ISBT applicator insertion was performed with image guidance by trans-rectal ultrasound and CT.ResultsThe median clinical target volume was 35.5 ml (2.4-142.1 ml) and the median delivered dose in equivalent dose in 2 Gy fractions (EQD2) for target volume D90 was 67.7 Gy (48.8-94.2 Gy, doses of external-beam radiation therapy and brachytherapy were combined). For re-irradiation patients, median EQD2 of D2cc for rectum and bladder, D0.5cc, D1cc, D2cc, D4cc, D6cc and D8cc for vaginal wall was 91.1 Gy, 100.9 Gy, 260.3 Gy, 212.3 Gy, 170.1 Gy, 117.1 Gy, 105.2 Gy, and 94.7 Gy, respectively. For those without prior radiation therapy, median EQD2 of D2cc for rectum and bladder, D0.5cc, D1cc, D2cc, D4cc, D6cc and D8cc for vaginal wall was 56.3 Gy, 54.3 Gy, 147.4 Gy, 126.2 Gy, 108.0 Gy, 103.5 Gy, 94.7 Gy, and 80.7 Gy, respectively. Among five patients with vaginal ulcer, three had prior pelvic radiation therapy in their initial treatment and three consequently suffered from fistula formation. On univariate analysis, re-irradiation and vaginal wall D2cc in EQD2 was the clinical predictors of vaginal ulcer (p = 0.035 and p = 0.025, respectively). The ROC analysis revealed that vaginal wall D2cc is the best predictor of vaginal ulcer. The 2-year incidence rates of vaginal ulcer in the patients with vaginal wall D2cc in EQD2 equal to or less than 145 Gy and over 145 Gy were 3.7% and 23.5%, respectively, with a statistically significant difference (p = 0.026).ConclusionsRe-irradiation and vaginal D2cc is a significant predictor of vaginal ulcer after HDR-ISBT for gynecologic malignancies. Three-dimensional image-guided treatment planning should be performed to ensure adequate target coverage while minimizing vaginal D2cc in order to avoid vagina ulcer.

The local efficacy of I-131 for F-18 FDG PET positive lesions in patients with recurrent or metastatic thyroid carcinomas.

Purpose: The aim of this study was to evaluate the local efficacy of I-131 for F-18 fluorodeoxyglucose positron emission tomography (FDG PET)-positive lesions. Methods: Whole-body FDG PET/CT was performed on 37 patients (55 cases: 16 men, 21 women; age range: 24–82 years; mean age ± standard deviation: 60.5 ± 16.0 years) with differentiated thyroid cancer after total thyroidectomy. The metastatic or recurrent lesions were divided into 5 categories: primary tumor bed, lymph node, lung, bone, and other. The well-defined lesions were measured on CT, and the sizes were compared before and after radioactive iodine therapy. Results: The analysis was performed on 37 patients with 44 lesions (lymph node:24, lung:16, bone:4). Sixteen lesions (70%) were increased and 7 (30%) showed no change or reduction when there was positive accumulation on FDG PET/CT and negative accumulation on I-131 (F(+)I(−)) group. In the positive accumulation for both FDG PET/CT and I-131 (F(+)I(+)) group, 5 lesions (63%) were increased and 3 (37%) showed no change or reduction. There was no significant difference for the tendency to increase in size between the F(+)I(−) and the F(+)I(+) groups. Conclusions: Lesions which show positive accumulations on FDG PET/CT have a greater tendency to increase in size. FDG-avid lesions are resistant to radioactive iodine therapy with or without I-131 uptake.

Dose error from deviation of dwell time and source position for high dose-rate 192Ir in remote afterloading system

The influence of deviations in dwell times and source positions for 192Ir HDR-RALS was investigated. The potential dose errors for various kinds of brachytherapy procedures were evaluated. The deviations of dwell time ΔT of a 192Ir HDR source for the various dwell times were measured with a well-type ionization chamber. The deviations of source position ΔP were measured with two methods. One is to measure actual source position using a check ruler device. The other is to analyze peak distances from radiographic film irradiated with 20 mm gap between the dwell positions. The composite dose errors were calculated using Gaussian distribution with ΔT and ΔP as 1σ of the measurements. Dose errors depend on dwell time and distance from the point of interest to the dwell position. To evaluate the dose error in clinical practice, dwell times and point of interest distances were obtained from actual treatment plans involving cylinder, tandem-ovoid, tandem-ovoid with interstitial needles, multiple interstitial needles, and surface-mold applicators. The ΔT and ΔP were 32 ms (maximum for various dwell times) and 0.12 mm (ruler), 0.11 mm (radiographic film). The multiple interstitial needles represent the highest dose error of 2%, while the others represent less than approximately 1%. Potential dose error due to dwell time and source position deviation can depend on kinds of brachytherapy techniques. In all cases, the multiple interstitial needles is most susceptible.

Expression of EpCAM and prognosis in early-stage glottic cancer treated by radiotherapy

Treatment of head and neck squamous cell carcinoma (HNSCC) often requires radiotherapy, but relapse can occur. There is, therefore, an urgent need for the identification of a predictive novel biomarker for radiosensitivity. The epithelial cell adhesion molecule (EpCAM) has been shown to promote the transformation of malignant tumors, and EpCAM may have prognostic significance, but it is not known if EpCAM determines prognosis, especially with respect to radiotherapy. Therefore, we determined the incidence of the expression of EpCAM in HNSCC and analyzed the prognostic value in patients with early‐stage glottic cancer treated with radiotherapy.

Inverse planning for combination of intracavitary and interstitial brachytherapy for locally advanced cervical cancer

The main purpose of this study was to compare three different treatment plans for locally advanced cervical cancer: (i) the inverse-planning simulated annealing (IPSA) plan for combination brachytherapy (BT) of interstitial and intracavitary brachytherapy, (ii) manual optimization based on the Manchester system for combination-BT, and (iii) the conventional Manchester system using only tandem and ovoids. This was a retrospective study of 25 consecutive implants. The high-risk clinical target volume (HR-CTV) and organs at risk were defined according to the GEC-ESTRO Working Group definitions. A dose of 6 Gy was prescribed. The uniform cost function for dose constraints was applied to all IPSA-generated plans. The coverage of the HR-CTV by IPSA for combination-BT was equivalent to that of manual optimization, and was better than that of the Manchester system using only tandem and ovoids. The mean V100 achieved by IPSA for combination-BT, manual optimization and Manchester was 96 ± 3.7%, 95 ± 5.5% and 80 ± 13.4%, respectively. The mean D100 was 483 ± 80, 487 ± 97 and 335 ± 119 cGy, respectively. The mean D90 was 677 ± 61, 681 ± 88 and 513 ± 150 cGy, respectively. IPSA resulted in significant reductions of the doses to the rectum (IPSA D2cm3: 408 ± 71 cGy vs manual optimization D2cm3: 485 ± 105 cGy; P = 0.03) and the bladder (IPSA D2cm3: 452 ± 60 cGy vs manual optimization D2cm3: 583 ± 113 cGy; P < 0.0001). In conclusion, combination-BT achieved better tumor coverage, and plans using IPSA provided significant sparing of normal tissues without compromising CTV coverage.

Two-piece customized mold technique for high-dose-rate brachytherapy on cancers of the buccal mucosa and lip

OBJECTIVE High-dose-rate (HDR) brachytherapy using a customized mold is a minimally invasive treatment for oral cancer; however, it is difficult to use this technique for buccal and lip cancers involving the commissura labiorum, owing to its anatomic form. The purpose of this study was to introduce an improved customized mold consisting of 2 pieces to allow the fixation of molds to these sites. STUDY DESIGN Five patients with buccal carcinoma and 1 patient with lip carcinoma were treated with this technique after external beam radiotherapy. One patient with neck metastasis underwent both neck dissection and partial tumor resection before HDR brachytherapy. RESULTS At the end of the follow-up period, 5 patients had no tumor recurrence, and 1 patient had suffered local recurrence. CONCLUSIONS Our technique is a viable therapeutic option for patients with buccal and lip carcinomas for whom the therapeutic modalities are limited by age, performance status, and other factors.

Radiotherapy for gastric lymphoma: a planning study of 3D conformal radiotherapy, the half-beam method, and intensity-modulated radiotherapy.

During radiotherapy for gastric lymphoma, it is difficult to protect the liver and kidneys in cases where there is considerable overlap between these organs and the target volume. This study was conducted to compare the three radiotherapy planning techniques of four-fields 3D conformal radiotherapy (3DCRT), half-field radiotherapy (the half-beam method) and intensity-modulated radiotherapy (IMRT) used to treat primary gastric lymphoma in which the planning target volume (PTV) had a large overlap with the left kidney. A total of 17 patients with gastric diffuse large B-cell lymphoma (DLBCL) were included. In DLBCL, immunochemotherapy (Rituximab + CHOP) was followed by radiotherapy of 40 Gy to the whole stomach and peri-gastric lymph nodes. 3DCRT, the half-field method, and IMRT were compared with respect to the dose–volume histogram (DVH) parameters and generalized equivalent uniform dose (gEUD) to the kidneys, liver and PTV. The mean dose and gEUD for 3DCRT was higher than for IMRT and the half-beam method in the left kidney and both kidneys. The mean dose and gEUD of the left kidney was 2117 cGy and 2224 cGy for 3DCRT, 1520 cGy and 1637 cGy for IMRT, and 1100 cGy and 1357 cGy for the half-beam method, respectively. The mean dose and gEUD of both kidneys was 1335 cGy and 1559 cGy for 3DCRT, 1184 cGy and 1311 cGy for IMRT, and 700 cGy and 937 cGy for the half-beam method, respectively. Dose–volume histograms (DVHs) of the liver revealed a larger volume was irradiated in the dose range <25 Gy with 3DCRT, while the half-beam method irradiated a larger volume of liver with the higher dose range (>25 Gy). IMRT and the half-beam method had the advantages of dose reduction for the kidneys and liver.

Asynchronous time-resolved FTIR study on ferroelectric liquid crystals

Transient infrared spectra of ferroelectric liquid crystals with tolane ring on different conditions have been measured by use of asynchronous time-resolved FT-IR method. The obtained spectra suggest that the temperature and applied voltage alter the rate of reorientation of the liquid crystal.

Plan quality comparison between 4-arc and 6-arc noncoplanar volumetric modulated arc stereotactic radiotherapy for the treatment of multiple brain metastases

To compare the plans of 4-arc and 6-arc noncoplanar volumetric modulated arc stereotactic radiotherapy (VMA-SRT) for multiple brain metastases and to investigate the cutoff value for the tumor number and volume for 6-arc rather than 4-arc VMA-SRT. We identified 24 consecutive multiple-target cases (3 to 19 targets in each case) with 189 total targets. We constructed plans using both 4- and 6-arc noncoplanar VMA-SRT. The prescribed dose was 36 Gy/6 fr, and it was delivered to 95% of the planning target volume (PTV). The plans were evaluated for the dose conformity using the Radiation Therapy Oncology Group and Paddick conformity indices (RCI and PCI), fall-off (Paddick gradient index [PGI]), and the normal brain dose. The median (range) RCI, PCI, and PGI was 0.94 (0.92 to 0.99), 0.89 (0.77 to 0.94), and 3.75 (2.24 to 6.54) for the 4-arc plan and 0.94 (0.91 to 0.98), 0.89 (0.76 to 0.94), and 3.65 (2.24 to 6.5) for the 6-arc plan, respectively. The median (range) of the normal brain dose was 910.3 cGy (381.4 to 1268.9) for the 4-arc plan and 898.8 cGy (377 to 1252.9) for the 6-arc plan. The PGI of the 6-arc plan was significantly superior to that of the 4-arc plan (p = 0.0076), and the optimal cutoff values for the tumor number and volume indicative of 6-arc (and not 4-arc) VMA-SRT were cases with ≥ 5 metastases and a PTV of ≥ 12.9 mL, respectively. The PCI values, however, showed no significant difference between the 2 plans. We believe these results will help in considering the use of 6-arc VMA-SRT for multiple brain metastases.