Postoperative Hypofractionated Intensity-Modulated Radiotherapy With Concurrent Chemotherapy in Cervical Cancer: The POHIM-CCRT Nonrandomized Controlled Trial.

Importance: Prospective data assessing the safety of hypofractionated (40 Gy in 16 fractions) radiotherapy (RT) among patients who receive postoperative concurrent chemoradiotherapy for cervical cancer are lacking. Objective: To evaluate the acute toxic effects of hypofractionated pelvic intensity-modulated radiotherapy (IMRT) with concurrent chemotherapy among women with cervical cancer who underwent radical hysterectomy. Design, Setting, and Participants: The POHIM-CCRT (Postoperative Hypofractionated Intensity-Modulated Radiation Therapy With Concurrent Chemotherapy in Cervical Cancer) study was designed as a multicenter, phase 2 nonrandomized controlled trial that accrued and followed up patients from June 1, 2017, to February 28, 2023. In total, 84 patients were enrolled from 5 institutions affiliated with the Korean Radiation Oncology Group. Eligible patients experienced lymph node metastasis, parametrial invasion, or positive resection margins after radical hysterectomy for treatment of confirmed cervical cancer. Intervention: Postoperative pelvic radiation using hypofractionated IMRT with 40 Gy in 16 fractions to the whole pelvis combined with concurrent chemotherapy. Main Outcomes and Measures: The primary end point was incidence of acute grade 3 or higher gastrointestinal tract, genitourinary, and hematologic toxic effects (based on the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0) in the evaluable population during RT or within 3 months after RT completion. Results: Of 84 patients enrolled, 5 dropped out prior to RT, and data from 79 patients were analyzed. The patients' median (IQR) age was 48 (42-58) years, and the median (IQR) tumor size was 3.7 (2.7-4.5) cm. Of these patients, 31 (39.7%) had lymph node metastasis, 4 (5.1%) had positive resection margins, and 43 (54.4%) had parametrial invasion. Grade 3 or higher acute toxic effects occurred in 2 patients (2.5% [90% CI, 0%-4.8%]). After a median (IQR) follow-up of 43.0 (21.1-59.0) months, the 3-year disease-free survival rate was 79.3%, and the overall survival rate was 98.0%. Conclusions: Findings from this nonrandomized control trial indicated that postoperative pelvic irradiation combined with concurrent chemotherapy using hypofractionated IMRT with 40 Gy in 16 fractions was safe and well-tolerated in women with cervical cancer. Studies assessing long-term toxic effects and oncological outcomes with longer follow-up periods are needed. Trial Registration: ClinicalTrials.gov Identifier: NCT03239613.

A dummy-run evaluation of postoperative hypofractionated intensity-modulated radiation therapy (POHIM-RT) trials for cervical cancer.

The postoperative hypofractionated intensity-modulated radiation therapy (POHIM-RT) trial is a phase II study to evaluate toxicity following hypofractionated intensity modulated radiation therapy (IMRT) for cervical cancer. This study describes the results of a benchmark procedure for RT quality assurance of the POHIM-RT trial. Six participating institutions were provided computed tomography for RT planning and an IMRT plan for a sample and were instructed to delineate volumes, create a treatment plan and quality assurance (QA) plan, and submit the results of all procedures. The inter-institutional agreements on RT volume and plan results were evaluated using the kappa value and dice similarity coefficients. The simultaneous truth and performance level estimation (STAPLE) method was employed to generate a consensus target volume. The treatment volumes, organs-at-risk volumes, and results of the RT plan and QA reported by the institutions were acceptable and adhered well to the protocol. In terms of clinical target volume (CTV) delineation, there were differences between the institutions, particularly in vaginal cuff and paracolpium subsites. Consensus CTV was generated from the collected CTVs with the STAPLE method. The participating institutions showed considerable agreement regarding volume, dose and QA results. To improve CTV agreement in CTV, we provided feedback with images of the consensus target volume and detailed written guidelines for specific subsites that were the most heterogeneous.

Ambient light robust gamut mapping for optical see-through displays.

An optical see-through (OST) display is affected more severely by ambient light than any other type of displays when placed in an outdoor environment with bright illuminance because of its transparency and thus, its inherent color distortion can worsen. It is hard to directly apply existing gamut mapping methods to an OST display because of its morphological gamut characteristic and the effect of ambient light. In this paper, we propose a new robust gamut mapping method which works against bright ambient light. The process is divided into two steps: lightness mapping (LM) and chroma reproduction. LM aligns the lightness level of sRGB gamut with OST gamut and partitions the region of OST gamut based on the relative size of the sRGB gamut and its lightness value. The second step (chroma reproduction) determines an appropriate chroma reproduction method (gamut compression or extension) and a proper direction for gamut mapping based on the characteristics of each region in order to minimize the effects of ambient light. The quality of color reproduction is qualitatively and quantitatively evaluated based on accurate measurements of the displayed colors. It has been experimentally confirmed that the proposed gamut mapping method can reduce color distortion more than the existing parametric gamut mapping algorithms.

Combination of external beam irradiation and high-dose-rate intraluminal brachytherapy for inoperable carcinoma of the extrahepatic bile ducts.

PURPOSE: To assess the feasibility and therapeutic benefits of a combination of external beam radiotherapy (EBRT) and high-dose-rate intraluminal brachytherapy (ILBT) for treating patients with inoperable carcinoma of the extrahepatic bile ducts. METHODS AND MATERIALS: Of 31 patients who received RT at the Yonsei Cancer Center, Yonsei University College of Medicine in Seoul, Korea between 1986 and 1995, 17 patients underwent EBRT alone (Group 1) and 14 patients were treated with EBRT in combination with high-dose-rate ILBT (Group 2). After external drainage, EBRT was delivered with a total dose ranging from 36 to 55 Gy (median 50.4) in both groups. High-dose-rate ILBT for the patients in Group 2 was performed using a high-intensity (192)Ir source (Gamma-med remote afterloading system) within the expandable intrabiliary prosthesis (Gianturco stent), inserted transhepatically at the site of the obstruction. The radiation dose of the high-dose-rate ILBT was prescribed at 1.5 cm from the center of the source with a single daily dose of 5 Gy to a total of 15 Gy given in three fractions. The response rate, patterns of treatment failure, treatment morbidity, and survival data in the two groups were compared. RESULTS: Although locoregional recurrence was the most common pattern of failure in both groups, no statistically significant difference was found in the recurrence rates between those who did and did not receive ILBT (53% for Group 1 vs. 36% for Group 2; p > 0.05). However, a prolongation of the median time to tumor recurrence was observed in the Group 2 patients (5 months for Group 1 vs. 9 months for Group 2; p = 0.06). When the EBRT dose delivered was >50 Gy, most patients experienced various degrees of GI symptoms, but the frequency of radiation-induced complications in the two groups was similar. No enhancement in treatment morbidity was attributed to the addition of high-dose-rate ILBT to EBRT. With a median follow-up of 12 months, the overall actuarial 2-year survival rate for Group 2 patients was significantly better than that for Group 1 patients (0% for Group 1 vs. 21% for Group 2; p = 0.015). CONCLUSION: Given these observations, we believe that the combined use of EBRT and high-dose-rate ILBT is a beneficial, relatively safe, and effective method of improving the treatment outcome in selected patients with inoperable carcinoma of the extrahepatic bile ducts.