Lợi ích xạ trị ung thư vú trái phối hợp hít sâu nín thở và hệ thống quản lý bề mặt quang học của máy Truebeam tại Bệnh viện Ung bướu Thành phố Hồ Chí Minh

TÓM TẮT Đối với ung thư vú (UTV) xạ trị là điều trị bổ túc cần thiết giúp giảm tái phát tại chỗ tại vùng, gia tăng sống còn. Tuy nhiên, xạ trị có tác dụng phụ lên tim mạch nhất là với UTV trái. Nhiều nghiên cứu đã chứng minh biến chứng và tử vong do tim mạch tăng tỉ lệ thuận với liều trung bình lên tim. Các kỹ thuật xạ trị mới trong xạ trị ung thư vú trái giúp tối ưu hóa liều vào thể tích xạ và bảo vệ tốt hơn cơ quan lành, càng đòi hỏi độ chính xác cao khi đặt bệnh. Các sai số do thiết bị hoặc đặt bệnh sẽ dẫn đến nguy cơ quá liều dung nạp hoặc thiếu liều và có nguy cơ tái phát. Vì vậy, xạ trị đòi hỏi sự chính xác cao trong suốt quá trình từ mô phỏng đến lập kế hoạch và tiến hành xạ trị. Xạ trị ung thư vú trái phối hợp hít sâu nín thở (DIBH - Deep Inspiration Breath - hold) và hệ thống quản lý bề mặt quang học (OSMS - Optical Surface Management System) làm cho tim di chuyển ra xa hơn khỏi vú, thành ngực trong quá trình xạ trị, giúp giảm liều tim một cách rõ rệt, vẫn đảm bảo được liều xạ lên thể tích đích. Ưu điểm của OSMS ngoài áp dụng cho đặt bệnh nhanh không cần xăm dấu trên da còn giám sát thời gian thực trong toàn bộ quá trình điều trị. Khi nhịp thở của bệnh nhân vượt quá một ngưỡng nhất định (0,3cm) chùm tia bức xạ sẽ bị tắt để ngăn ngừa độc tính. Do đó, hiểu và nắm rõ lợi ích quy trình đặt bệnh giúp đạt mục tiêu điều trị đồng thời giảm thời gian đặt bệnh để người bệnh có tâm lý thoải mái hơn, giảm áp lực về số lượng bệnh, nhất là đối với các trung tâm xạ trị lớn. ABSTRACT BENEFITS OF LEFT BREAST CANCER RADIATION COMBINATION OF DEEP INSPIRATION BREATH - HOLD AND OPTICAL SURFACE MANAGEMENT SYSTEM OF TRUEBEAM MACHINE AT CANCER HOSPITAL HO CHI MINH CITY Background: For breast cancer, radiation therapy is an essential adjuvant treatment to help reduce local recurrence and increase survival. However, radiation therapy has adverse effects on the cardiovascular systemespecially for left breast cancer. Several studies have demonstrated that cardiovascular morbidity and mortality increase in proportion to the mean cardiac dose. New radiotherapy techniques in radiation therapy for left breast cancer help optimize dose to radiation volume and better protect healthy organs, which requires high accuracy when patient set - up. Errors due to equipment or patient set - up will lead to the risk of overdosage or underdosage and risk of relapse. Therefore, radiation therapy requires high precision throughout the process from simulation to planning and conducting radiation therapy. Radiation therapy for left breast cancer combined with Deep Inspiration Breath - hold (DIBH) and Optical Surface Management System (OSMS)causes the heart to move further away from the breast and chest wall during radiation therapy, helping to reduce the cardiac dose significantly, still ensuring the radiation dose to the target volume. The advantage of OSMS is that in addition to being applied for fastpatient set - up, without tattooing on the skin, it also provides real - time monitoring during the entire treatment process. When the patient’s breathing rate exceeds a certain threshold (0,3cm) the radiation beam is turned off to prevent toxicity. Therefore, understanding and understanding the benefits of patient set - up helps to achieve treatment goals, while reducing patient set - up time for more comfort, reducing pressure on the number of patients, especially for patients large radiotherapy center. Keyword: Radiation therapy for left breast cancer, Deep Inspiration Breath - hold, Optical Surface Management System, cardiovascular risk.

Dosimetric Comparison of Intraoperative Radiotherapy and SRS for Liver Metastases

Purpose/ObjectivesTo perform a dosimetric comparison between kilovoltage intraoperative radiotherapy (IORT) and stereotactic radiosurgery (SRS) simulating both deep-inspiration breath-hold (DIBH) and free-breathing (FB) modalities for patients with liver metastases.Methods/MaterialsDiagnostic computed tomographies (CT) of patients carrying one or two lesions <4 cm and who underwent surgery were retrospectively screened and randomly selected for the study. For DIBH-SRS, a gross target volume (GTV) plus planning target volume (PTV) were delineated. For FB-SRS, a GTV plus an internal target volume (ITV) and PTV were defined. Accounting for the maximal GTV diameters, a modified GTV (GTV-IORT) was expanded circumferentially to simulate a resection cavity. The best suitable round-applicator size was thereafter selected. All treatment plans were calculated homogeneously to deliver 40 Gy. Doses delivered to organs at risk (OAR) and target volumes were compared for IORT vs. both SRS modalities.ResultsEight patients encompassing 10 lesions were included in the study. The mean liver volume was 2,050.97 cm3 (SD, 650.82), and the mean GTV volume was 12.23 cm3 (SD, 12.62). As for target structures, GTV-IORT [19.44 cm3 (SD, 17.26)] were significantly smaller than both PTV DIBH-SRS [30.74 cm3 (SD, 24.64), p = 0.002] and PTV FB-SRS [75.82 cm3 (SD, 45.65), p = 0.002]. The median applicator size was 3 cm (1.5–4.5), and the mean IORT simulated delivery time was 45.45 min (SD, 19.88). All constraints were met in all modalities. Liver V9.1 showed significantly smaller volumes with IORT [63.39 cm3 (SD, 35.67)] when compared to DIBH-SRS [150.12 cm3 (SD, 81.43), p = 0.002] or FB-SRS [306.13 cm3 (SD, 128.75), p = 0.002]. No other statistical or dosimetrically relevant difference was observed for stomach, spinal cord, or biliary tract. Mean IORT D90 was 85.3% (SD, 6.05), whereas D95 for DIBH-SRS and FB-SRS were 99.03% (SD, 1.71; p = 0.042) and 98.04% (SD, 3.46; p = 0.036), respectively.ConclusionKilovoltage IORT bears the potential as novel add-on treatment for resectable liver metastases, significantly reducing healthy liver exposure to radiation in comparison to SRS. Prospective clinical evidence is required to confirm this hypothesis.

Od 2D do DIBH, przegląd technik radioterapeutycznych stosowanych w napromienianiu nowotworów piersi From 2D to DIBH, review of radiotherapeutic techniques related to irradiation of breast cancer

Nowotwór piersi jest to nowotwór złośliwy powstający z komórek gruczołu piersiowego, który rozwija się miejscowo w piersi oraz daje przerzuty do węzłów chłonnych i narządów wewnętrznych (płuc, wątroby, kości i mózgu). Ponad 23% zachorowań na nowotwory kobiet w Polsce, jak i na świecie stanowią nowotwory piersi. Na przestrzeni ostatnich lat techniki napromieniania nowotworów piersi ulegają ciągłemu rozwojowi. Celem pracy było poglądowe przedstawienie technik radioterapeutycznych stosowanych w napromienianiu nowotworów piersi, od dwuwymiarowej 2D techniki statycznej poprzez techniki dynamiczne (IMRT technika z modulacją intensywnością dawki (ang. intensity modulated radiation therapy), VMAT technika obrotowa z modulacją intensywności dawki (ang. volumetric modulated arc therapy), aż do techniki DIBH techniki napromieniania na głębokim wstrzymanym wdechu (ang. deep inspiration breath hold). W pracy skupiono się na przedstawieniu realizacji omawianych technik i opisie jak dana technika wpływa na rozkład dawki w planowanej objętości do napromieniania PTV (ang. Planning Target Volume) oraz na dawki w narządach krytycznych w radioterapii nowotworów piersi.

Fractionated deep-inspiration breath-hold ZTE Compared with Free-breathing four-dimensional ZTE for detecting pulmonary nodules in oncological patients underwent PET/MRI

The zero echo time (ZTE) technique has improved the detection of lung nodules in PET/MRI but respiratory motion remains a challenge in lung scan. We investigated the feasibility and performance of fractionated deep-inspiration breath-hold (FDIBH) three-dimensional (3D) ZTE FDG PET/MRI for assessing lung nodules in patients with proved malignancy. Sixty patients who had undergone ZTE FDG PET/MRI and chest CT within a three-day interval were retrospectively included. Lung nodules less than 2 mm were excluded for analysis. Two physicians checked the adequacy of FDIBH ZTE and compared the lung nodule detection rates of FDIBH 3D ZTE and free-breathing (FB) four-dimensional (4D) ZTE, with chest CT as the reference standard. FDIBH resolved the effect of respiratory motion in 49 patients. The mean number and size of the pulmonary nodules identified in CT were 15 ± 31.3 per patient and 5.9 ± 4.6 mm in diameter. The overall nodule detection rate was 71% for FDIBH 3D ZTE and 70% for FB 4D ZTE (p = 0.73). FDIBH 3D ZTE significantly outperformed FB 4DZTE in detecting lung base nodules (72% and 68%; p = 0.03), especially for detecting those less than 6 mm (61% and 55%; p = 0.03). High inter-rater reliability for FDIBH 3D ZTE and FB 4D ZTE (k = 0.9 and 0.92) was noted. In conclusion, the capability of FDIBH 3D ZTE in respiratory motion resolution was limited with a technical failure rate of 18%. However, it could provide full expansion of the lung in a shorter scan time which enabled better detection of nodules (< 6 mm) in basal lungs, compared to FB 4D ZTE.