Drug Combinations in Preoperative Chemoradiation for Rectal Cancer
Preoperative radiotherapy has an accepted role in reducing the risk of local recurrence in locally advanced resectable rectal cancer, particularly when the circumferential resection margin is breached or threatened, according to magnetic resonance imaging. Fluoropyrimidine-based chemoradiation can obtain a significant down-sizing response and a curative resection can then be achieved. Approximately, 20% of the patients can also obtain a pathological complete response, which is associated with less local recurrences and increased survival. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Rob Glynne-Jones, Carlos Carvalho Source Type: research
Definitive Chemoradiotherapy (“Watch-and-Wait” Approach)
Preoperative chemoradiotherapy (CRT) followed by total mesorectal excision has been the standard of care for locally advanced patients with rectal cancer. Some patients achieve a pathologic complete response (pCR) to CRT and the oncologic outcomes are particularly favorable in this group. The role of surgery in patients with a pCR is now being questioned as radical rectal resection is associated with significant morbidity and long-term effects on quality of life. In an attempt to better tailor therapy, there is an interest in a “watch-and-wait” approach in patients who have a clinical complete response (cCR) after CRT ...
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Karyn A. Goodman Source Type: research
Irradiation of Very Locally Advanced and Recurrent Rectal Cancer
Adjuvant therapy with chemoradiation or short-course radiation in addition to improvements in surgical technique has led to improved outcomes for patients with locally advanced rectal cancer. Local recurrence rates of less than 10% and 5-year survival rate of 60% or higher is expected. However, for patients with very locally advanced primary or locally recurrent disease in whom surgical resection is likely to be associated with incomplete resection, survival and disease control rates are poor and standard doses of adjuvant radiation or chemoradiation are relatively ineffective. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Michael G. Haddock Source Type: research
Advancing Techniques of Radiation Therapy for Rectal Cancer
Since the advent of radiation therapy for rectal cancer, there has been continual investigation of advancing technologies and techniques that allow for improved dose conformality to target structures while limiting irradiation of surrounding normal tissue. For locally advanced disease, intensity modulated and proton beam radiation therapy both provide more highly conformal treatment volumes that reduce dose to organs at risk, though the clinical benefit in terms of toxicity reduction is unclear. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Sagar A. Patel, Jennifer Y. Wo, Theodore S. Hong Source Type: research
Which Patients With Rectal Cancer Do Not Need Radiotherapy?
According to current guidelines, the standard treatment for locally advanced rectal cancer patients is preoperative (chemo)radiotherapy followed by total mesorectal excision surgery and adjuvant chemotherapy. Improvements in surgical techniques, imaging modalities, chemotherapy regimens, and radiotherapy delivery have reduced local recurrence rates to less than 10%. The current challenge in rectal cancer treatment lies in the prevention of distant metastases, which still occur in more than 25% of the patients. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Ines Joye, Karin Haustermans Source Type: research
Preoperative Treatment of Locally Advanced Rectal Cancer: Assets and Drawbacks of Short Course and Long Course in Clinical Practice
Preoperative short-course radiotherapy and preoperative long-course chemoradiotherapy are the standards of care for high-risk rectal cancer in different parts of the world. Both treatments are effective in local control and carry a low morbidity. The advantage of short course is its simplicity, whereas long course has the advantage of downsizing tumors thus increasing the chance of sphincter preservation. Although 2 randomized trials comparing short course and long course have been performed, the better form of preoperative treatment remains a subject of discussion. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Samuel Y. Ngan Source Type: research
Timing of Therapies in the Multidisciplinary Treatment of Locally Advanced Rectal Cancer: Available Evidence and Implications for Routine Practice
A multimodality disciplinary approach is paramount for the management of locally advanced rectal cancer. Over the last decade, (chemo)radiotherapy followed by surgery plus or minus adjuvant chemotherapy has represented the mainstay of treatment for this disease. Nevertheless, robust evidence suggesting the optimal timing and sequence of therapies in this setting has been overall limited. A number of questions are still unsolved including the length of the interval between neoadjuvant radiotherapy and surgery or the timing of systemic chemotherapy. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Francesco Sclafani, Ian Chau Source Type: research
Rectal Cancer: The Radiation Oncologist: The Great Watchmaker
Even with the passage of time, the management of rectal cancer remains a fascinating challenge for the clinician. Firstly, the dramatic reduction in the rate of pelvic failure should be considered as one of the major achievements in oncology over the past decades. Keeping in mind that in the 1980s, up to 50% of the patients suffering from a locally advanced tumor developed a pelvic recurrence, the decrease in this fearsome event to less than 10% without any contribution from new drugs is an important observation. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Philippe Maingon, Florence Huguet Source Type: research
Toward Restored Bowel Health in Rectal Cancer Survivors
As technology gets better and better, and as clinical research provides more and more knowledge, we can extend our ambition to cure patients from cancer with restored physical health among the survivors. This increased ambition requires attention to grade 1 toxicity that decreases quality of life. It forces us to document the details of grade 1 toxicity and improve our understanding of the mechanisms. Long-term toxicity scores, or adverse events as documented during clinical trials, may be regarded as symptoms or signs of underlying survivorship diseases. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - May 27, 2016 Category: Cancer & Oncology Authors: Gunnar Steineck, Heike Schmidt, Eleftheria Alevronta, Fei Sjöberg, Cecilia Magdalena Bull, Dirk Vordermark Source Type: research
Validity of Current Stereotactic Body Radiation Therapy Dose Constraints for Aorta and Major Vessels
Understanding dose constraints for critical structures in stereotactic body radiation therapy (SBRT) is essential to generate a plan for optimal efficacy and safety. Published dose constraints are derived by a variety of methods, including crude statistics, actuarial analysis, modeling, and simple biologically effective dose (BED) conversion. Many dose constraints reported in the literature are not consistent with each other, secondary to differences in clinical and dosimetric parameters. Application of a dose constraint without discriminating the variation of all the factors involved may result in suboptimal treatment. (S...
Source: Seminars in Radiation Oncology - March 20, 2016 Category: Cancer & Oncology Authors: Jinyu Xue, Gregory Kubicek, Ashish Patel, Benjamin Goldsmith, Sucha O. Asbell, Tamara A. LaCouture Source Type: research
Dose and Volume of the Irradiated Main Bronchi and Related Side Effects in the Treatment of Central Lung Tumors With Stereotactic Radiotherapy
High radiation dose to the main bronchi can result in stenosis, occlusion or fistula formation, and death. Only 8 articles have reported side effects to the main bronchi from stereotactic body radiation therapy (SBRT), mostly with only one symptomatic complication per article. Therefore, we calculated the dose to the bronchial structures, such as trachea; mainstem bronchi; intermediate bronchus; upper-, middle-, and lower-lobe bronchus; and the segmental bronchi in 134 patients with central tumors and calculated the normal tissue complication probability (NTCP) for each of these structures, with toxicity determination base...
Source: Seminars in Radiation Oncology - March 20, 2016 Category: Cancer & Oncology Authors: Marloes Duijm, W. Schillemans, Joachim G. Aerts, B. Heijmen, Joost J. Nuyttens Source Type: research
Dose-Response Model for Chest Wall Tolerance of Stereotactic Body Radiation Therapy
Many recent studies have described rib fractures and chest wall pain following stereotactic body radiation therapy (SBRT). Although these toxicities generally are not life-threatening, the chest wall and ribs are considered dose-limiting tissues because of the potential effect on patients׳ quality of life. Few studies have reported dose-response models that can provide quantitative estimates of risk as a function of dose and volume. Notably, Memorial Sloan Kettering Cancer Center (Mutter et al8) analyzed grade 2 or higher chest wall toxicity in a cohort of 126 patients treated with linear accelerator–based SBRT; the aut...
Source: Seminars in Radiation Oncology - March 20, 2016 Category: Cancer & Oncology Authors: Frank Kimsey, Jesse McKay, Jeffrey Gefter, Michael T. Milano, Vitali Moiseenko, Jimm Grimm, Ronald Berg Source Type: research
Multisession Radiosurgery for Hearing Preservation
Clinically relevant dose-tolerance limits with reliable estimates of risk in 1-5 fractions for cochlea are still unknown. Timmerman׳s limits from the October 2008 issue of Seminars in Radiation Oncology have served as the basis for clinical practice, augmented by updated constraints in TG-101 and QUANTEC, but the corresponding estimates of risk have not yet been well-reported. A total of 37 acoustic neuroma CyberKnife cases from Medstar Georgetown University Hospital treated in 3 or 5 fractions were combined with single-fraction Gamma Knife data from the 69 cases in Timmer 2009 to form an aggregate dataset of 106 cochlea ...
Source: Seminars in Radiation Oncology - March 20, 2016 Category: Cancer & Oncology Authors: Abdul Rashid, Sana D. Karam, Beenish Rashid, Jeffrey H. Kim, Dalong Pang, Walter Jean, Jimm Grimm, Sean P. Collins Source Type: research
Introduction and Clinical Overview of the DVH Risk Map
Radiation oncologists need reliable estimates of risk for various fractionation schemes for all critical anatomical structures throughout the body, in a clinically convenient format. Reliable estimation theory can become fairly complex, however, and estimates of risk continue to evolve as the literature matures. To navigate through this efficiently, a dose-volume histogram (DVH) Risk Map was created, which provides a comparison of radiation tolerance limits as a function of dose, fractionation, volume, and risk level. (Source: Seminars in Radiation Oncology)
Source: Seminars in Radiation Oncology - March 20, 2016 Category: Cancer & Oncology Authors: Sucha O. Asbell, Jimm Grimm, Jinyu Xue, Meng-Sang Chew, Tamara A. LaCouture Source Type: research
Esophageal Dose Tolerance in Patients Treated With Stereotactic Body Radiation Therapy
Mediastinal critical structures such as trachea, bronchus, esophagus, and heart are among the dose-limiting factors for stereotactic body radiation therapy (SBRT) to central lung lesions. The purpose of this study was to characterize the risk of esophagitis for patients treated with SBRT and to develop a statistical dose-response model to assess the equivalent uniform dose, D10%, D5cc, D1cc, and Dmax, to the esophagus and the risk of toxicity. Toxicity outcomes of a dose-escalation study of 56 patients who had taken CyberKnife treatment from 45-60Gy in 3-7 fractions at the Erasmus MC-Daniel den Hoed Cancer Center were util...
Source: Seminars in Radiation Oncology - March 20, 2016 Category: Cancer & Oncology Authors: Joost J. Nuyttens, Vitali Moiseenko, Mark McLaughlin, Sheena Jain, Scott Herbert, Jimm Grimm Source Type: research
