The Role of Ablative Radiotherapy to Liver Oligometastases from Colorectal Cancer

Purpose of Review This review describes recent data supporting locoregional ablative radiation in the treatment of oligometastatic colorectal cancer liver metastases. Recent Findings Stereotactic body radiotherapy (SBRT) demonstrates high rates of local control in colorectal cancer liver metastases when a biologically equivalent dose of > 100 Gy is delivered. Future innovations to improve the efficacy of SBRT include MRI-guided radiotherapy (MRgRT) to enhance target accuracy, systemic immune activation to treat extrahepatic disease, and genomic customization. Selective internal radiotherapy (SIRT) with y-90 is an intra-arterial therapy that delivers high doses to liver metastases internally which has shown to increase liver disease control in phase 3 trials. Advancements in transarterial radioembolization (TARE) dosimetry could improve local control and decrease toxicity. Summary SBRT and SIRT are both promising options in treating unresectable metastatic colorectal cancer liver metastases. Identification of oligometastatic patients who receive long-term disease control from either therapy is essential. Future advancements focusing on improving radiation design and customization could further improve efficacy and toxicity.

Quantitative assessments of late radiation-induced skin and soft tissue toxicity and correlation with RTOG scales and biological equivalent dose in breast cancer

Purpose Radiation-induced toxicity (RIT) is usually assessed by inspection and palpation. Due to their subjective and unquantitative nature, objective methods are required. This study aimed to determine whether a quantitative tool is able to assess RIT and establish an underlying BED-response relationship in breast cancer. Methods Patients following seven different breast radiation protocols were recruited to this study for RIT assessment with qualitative and quantitative examination. The biologically equivalent dose (BED) was used to directly compare different radiation regimens. RIT was subjectively evaluated by physicians using the Radiation Therapy Oncology Group (RTOG) late toxicity scores. Simultaneously an objective multiprobe device was also used to quantitatively assess late RIT in terms of erythema, hyperpigmentation, elasticity and skin hydration. Results In 194 patients, in terms of the objective measurements, treated breasts showed higher erythema and hyperpigmentation and lower elasticity and hydration than untreated breasts (p < 0.001, p < 0.001, p < 0.001, p = 0.019, respectively). As the BED increased, Δerythema and Δpigmentation gradually increased as well (p = 0.006 and p = 0.002, respectively). Regarding the clinical assessment, the increase in BED resulted in a higher RTOG toxicity grade (p < 0.001). Quantitative assessments were consistent with RTOG scores. As the RTOG toxicity grade increased, the erythema and pigmentation values increased, and the elasticity index decreased (p < 0.001, p = 0.016, p = 0.005, respectively). Conclusions The multiprobe device can be a sensitive and simple tool for research purpose and quantitatively assessing RIT in patients undergoing radiotherapy for breast cancer. Physician-assessed toxicity scores and objective measurements revealed that the BED was positively associated with the severity of RIT.

A surveillance study of patterns of reirradiation practice using external beam radiotherapy in Japan

The aim of this study was to survey the present status and patterns of reirradiation (Re-RT) practice using external beam radiotherapy in Japan. We distributed an e-mail questionnaire to the Japanese Society for Radiation Oncology partner institutions, which consisted of part 1 (number of Re-RT cases in 2008–2012 and 2013–2018) and part 2 (indications and treatment planning for Re-RT and eight case scenarios). Of the 85 institutions that replied to part 1, 75 (88%) performed Re-RTs. However, 59 of these 75 institutions (79%) reported difficulty in obtaining Re-RT case information from their databases. The responses from 37 institutions included the number of Re-RT cases, which totaled 508 in the period from 2009 to 2013 (institution median 3; 0–235), and an increase to 762 cases in the period from 2014 to 2018 (12.5; 0–295). A total of 47 physicians responded to part 2 of the survey. Important indications for Re-RT that were considered were age, performance status, life expectancy, absence of distant metastases and time interval since previous radiotherapy. In addition to clinical decision-making factors, previous total radiation dose, volume of irradiated tissue and the biologically equivalent dose were considered during Re-RT planning. From the eight site-specific scenarios presented to the respondents, &gt;60% of radiation oncologists agreed to perform Re-RT. Re-RT cases have increased in number, and interest in Re-RT among radiation oncologists has increased recently due to advances in technology. However, several problems exist that emphasize the need for consensus building and the establishment of guidelines for practice and prospective evaluation.

Comparative Mathematical Radiotherapy of Some Dog and Human Cancers

BackgroundCancer is a serious disease in human and canine species and can be managed using surgical, chemotherapeutic, immunotherapeutic and radiotherapeutic interventions. But for radiotherapy, determination of radiotherapeutic doses for specific cancer treatment is a serious problem both in medical and veterinary oncology.ResultsIn view of this, a number of formulas used in medical oncology has been adopted and applied for determination of effective radiotherapeutic doses especially for dogs. Findings revealed that the formulas could be used to estimate radiotherapeutic doses for a number of cancer diseases in dogs. More so, factors such as age, sex, type of cancer, location of cancer and biological effective dose should be considered. The most relevant formula is BED = nd [1 + (d)/(α/β)] where BED = biologically equivalent dose; d = dose per fraction; α/β = ratio for tumor (10) and n = number of fractions.ConclusionsMetronomic radiotherapy which may be defined as repetitive exposure of cytotoxic radio-active rays of < 2 Gy at regular and frequent intervals of 10-25 fractions of total 45 Gy may be safer for the treatment of malignancies in dog and human. But BED of 45 60 Gy has cancer control rate of 48 – 67%, and 50% probabilities of complications was caused by radiation rays of 54 Gy. Whereas a dose of > 2Gy in 2 fractions may improve quality of life and reduce chronic pain associated with terminal malignancies.

Peran Radiasi Pada Tata Laksana Keloid

Keloid merupakan salah satu lesi jinak pada kulit yang timbul akibat respons penyembuhan luka yangabnormal. Meskipun bersifat jinak, namun keloid dapat menimbulkan gejala klinis yang mengganggu. Terdapatbanyak pilihan terapi untuk keloid yang bersifat invasif maupun non-invasif. Pembedahan merupakan modalitasinvasif yang paling umum digunakan, meskipun angka rekurensi pasca terapi tunggal dengan pembedahandinilai cukup tinggi yakni mencapai 50-100% dalam 5 tahun. Radioterapi dapat dilakukan sebagai monoterapimaupun sebagai terapi adjuvan pasca bedah dalam tata laksana keloid. Terapi keloid dengan pembedahandiikuti dengan radiasi menghasilkan angka rekurensi kurang dari 10% pada 1 tahun pertama pascaterapi.Radioterapi yang dilakukan dapat berupa brakiterapi maupun radiasi eksterna. Radiasi dapat menurunkanproliferasi fibroblas dan sel endotel yang selanjutnya mengurangi produksi kolagen. Radioterapi pascabedahdianjurkan untuk dimulai dalam waktu kurang dari 48 jam dengan total dosis yang masih menjadi perdebatan.Kaitan antara dosis dan efek radiasi dengan biologically equivalent dose (BED) menjadi dasar pembuatanpedoman. BED lebih dari 30 Gy dianggap efektif untuk menurunkan angka rekurensi keloid.Kata kunci: keloid, terapi, pascabedah, radiasi, rekurensi

Clinical outcomes of 130 patients with primary and secondary lung tumors treated with Cyberknife robotic stereotactic body radiotherapy

Background Authors report clinical outcomes of patients treated with robotic stereotactic body radiotherapy (SBRT) for primary, recurrent and metastatic lung lesions. Patients and methods 130 patients with 160 lesions were treated with Cyberknife SBRT, including T1-3 primary lung cancers (54%), recurrent tumors (22%) and pulmonary metastases (24%). The mean biologically equivalent dose (BED10Gy) was 151 Gy (72–180 Gy). Median prescribed dose for peripheral and central lesions was 3×20 Gy and 3×15 Gy, respectively. Local control (LC), overall survival (OS), and cause-specific survival (CSS) rates, early and late toxicities are reported. Statistical analysis was performed to identify factors influencing local tumor control. Results Median follow-up time was 21 months. In univariate analysis, higher dose was associated with better LC and a cut-off value was detected at BED10Gy ≤ 112.5 Gy, resulting in 1-, 2-, and 3-year actuarial LC rates of 93%, vs 73%, 80% vs 61%, and 63% vs 54%, for the high and low dose groups, respectively (p = 0.0061, HR = 0.384). In multivariate analysis, metastatic origin, histological confirmation and larger Planning Target Volume (PTV) were associated with higher risk of local failure. Actuarial OS and CSS rates at 1, 2, and 3 years were 85%, 74% and 62%, and 93%, 89% and 80%, respectively. Acute and late toxicities ≥ Gr 3 were observed in 3 (2%) and 6 patients (5%), respectively. Conclusions Our favorable LC and survival rates after robotic SBRT, with low rates of severe toxicities, are coherent with the literature data in this mixed, non-selected study population.

A surveillance study of the current status of reirradiation and patterns of practice

The aim of this study was to survey the current status of reirradiation (Re-RT) and patterns of practice in Japan. An email questionnaire was sent to Kansai Cancer Therapist Group partner institutions, using questions similar to those in the Canadian radiation oncologist (RO) survey (2008). A total of 34 ROs from 28 institutions returned the survey. All 28 institutions experienced Re-RT cases in 2014. However, 26 of the 28 institutions (93%) reported difficulty in obtaining Re-RT case information from their respective databases. Responses from 19 institutions included the number of Re-RT cases; this rose from 183 in the period 2005–2009 (institution median = 4; 2–12.9) to 562 in the period 2010–2014 (institution median = 26; 2–225). Important considerations for indication of Re-RT were age (65%), performance status (83%), life expectancy (70%), absence of distant metastases (67%), and interval since previous treatment (73%). Previous total radiation dose (48%), volume of tissue irradiated (72%), and the biologically equivalent dose (BED; 68.5%) were taken into account during Re-RT planning. These factors were similar to those considered in the Canadian survey; however, the present study did not consider age. In eight site-specific scenarios, barring central nervous system recurrence, more than 90% of ROs agreed to perform Re-RT, which was higher than the percentage observed in the Canadian survey. Re-RT cases have increased in number and aroused interest among ROs in this decade of advanced technology. However, consensus building to establish guidelines for the practice and prospective evaluation of Re-RT is required.