Emerging role of intensity-modulated radiation therapy in anorectal cancer

Clinical course and treatment of radiation-induced hemorrhagic gastritis: a case series study

Radiation-induced hemorrhagic gastritis is a relatively uncommon complication of irradiation that can be severe. However, appropriate treatment guidelines have not yet been established because of the small number of known cases. At our hospital, we encountered nine cases of radiation-induced hemorrhagic gastritis between July 2005 and July 2018. All patients initially underwent argon plasma coagulation (APC) for hemostasis. The treatment was highly effective, and hemostasis was successfully achieved in eight of the cases. Hemostasis could not be achieved in one case treated with APC; therefore, surgical resection was required. This patient had risk factors, such as liver cirrhosis and a history of abdominal surgery. Our case series suggests that APC is an effective hemostatic method that should be considered as the initial treatment option for radiation-induced hemorrhagic gastritis; however, surgical resection may be considered when the patient is at high risk for rebleeding.

Radiation proctopathy

Radiation therapy is a widely utilized treatment modality for pelvic malignancies, including prostate cancer, rectal cancer, and cervical cancer. Given its fixed position in the pelvis, the rectum is at a high risk for injury secondary to ionizing radiation. Despite advances made in radiation science, up to 75% of the patients will suffer from acute radiation proctitis and up to 20% may experience chronic symptoms. Symptoms can be variable and include diarrhea, bleeding, incontinence, and fistulization. A multitude of treatment options exist. This article summarizes the latest knowledge relating to radiation proctopathy focusing on the vast array of treatment options.

Gastrointestinal radiation injury: Symptoms, risk factors and mechanisms

Ionising radiation therapy is a common treatment modality for different types of cancer and its use is expected to increase with advances in screening and early detection of cancer. Radiation injury to the gastrointestinal tract is important factor working against better utility of this important therapeutic modality. Cancer survivors can suffer a wide variety of acute and chronic symptoms following radiotherapy, which significantly reduces their quality of life as well as adding an extra burden to the cost of health care. The accurate diagnosis and treatment of intestinal radiation injury often represents a clinical challenge to practicing physicians in both gastroenterology and oncology. Despite the growing recognition of the problem and some advances in understanding the cellular and molecular mechanisms of radiation injury, relatively little is known about the pathophysiology of gastrointestinal radiation injury or any possible susceptibility factors that could aggravate its severity. The aims of this review are to examine the various clinical manifestations of post-radiation gastrointestinal symptoms, to discuss possible patient and treatment factors implicated in normal gastrointestinal tissue radiosensitivity and to outline different mechanisms of intestinal tissue injury.

Gastrointestinal radiation injury: Prevention and treatment

With the recent advances in detection and treatment of cancer, there is an increasing emphasis on the efficacy and safety aspects of cancer therapy. Radiation therapy is a common treatment for a wide variety of cancers, either alone or in combination with other treatments. Ionising radiation injury to the gastrointestinal tract is a frequent side effect of radiation therapy and a considerable proportion of patients suffer acute or chronic gastrointestinal symptoms as a result. These side effects often cause morbidity and may in some cases lower the efficacy of radiotherapy treatment. Radiation injury to the gastrointestinal tract can be minimised by either of two strategies: technical strategies which aim to physically shift radiation dose away from the normal intestinal tissues, and biological strategies which aim to modulate the normal tissue response to ionising radiation or to increase its resistance to it. Although considerable improvement in the safety of radiotherapy treatment has been achieved through the use of modern optimised planning and delivery techniques, biological techniques may offer additional further promise. Different agents have been used to prevent or minimize the severity of gastrointestinal injury induced by ionising radiation exposure, including biological, chemical and pharmacological agents. In this review we aim to discuss various technical strategies to prevent gastrointestinal injury during cancer radiotherapy, examine the different therapeutic options for acute and chronic gastrointestinal radiation injury and outline some examples of research directions and considerations for prevention at a pre-clinical level.

The therapeutic and adverse effects of modified radiation fields for patients with rectal cancer

PURPOSE

To compare the therapeutic effect and complications of modified radiation fields (MRFs) with those of conventional pelvic radiation fields (CPRFs) for rectal cancer.

METHODS AND MATERIALS

From December 1996 to October 2009, a total of 160 patients with rectal carcinoma who received total mesorectal excision and postoperative radiotherapy were examined. Ninety-four patients were in the CPRFs group, and 66 were in the MRFs group. The dose was 50 Gy per 25 fractions in the initial plan.

RESULTS

The treatment volume and the volume of small bowel that received more than 15 Gy of the MRFs was smaller than that of the CPRFs (P < .001). The rates of local recurrence, overall survival, and disease-free survival were not statistically significant between the MRFs and CPRFs groups (P > .05). There was a statistical difference (P < .05) in the incidence of acute toxicity, which included serious complications in the lower digestive tract (grade ≥3). The completion rate for the initial radiotherapy plan was higher in the MRFs group than in the CPRFs group (P = .027).

CONCLUSIONS

Compared with CPRFs, MRFs manifested a lower incidence of complications and the same therapeutic effects. This finding will facilitate the clinical application of MRFs for patients with rectal cancer.

Volumetric modulated arc therapy: a review of current literature and clinical use in practice

Volumetric modulated arc therapy (VMAT) is a novel radiation technique, which can achieve highly conformal dose distributions with improved target volume coverage and sparing of normal tissues compared with conventional radiotherapy techniques. VMAT also has the potential to offer additional advantages, such as reduced treatment delivery time compared with conventional static field intensity modulated radiotherapy (IMRT). The clinical worldwide use of VMAT is increasing significantly. Currently the majority of published data on VMAT are limited to planning and feasibility studies, although there is emerging clinical outcome data in several tumour sites. This article aims to discuss the current use of VMAT techniques in practice and review the available data from planning and clinical outcome studies in various tumour sites including prostate, pelvis (lower gastrointestinal, gynaecological), head and neck, thoracic, central nervous system, breast and other tumour sites.

Metachronous anal canal and prostate cancers with simultaneous definitive therapy: a case report and review of the literature

Anal canal cancer is rare, accounting for only 1.3% of all gastrointestinal tract malignancies. Prostate cancer incidence is much higher and accounts for 27.6% of all malignancies in men. Treatment guidelines for anal cancer involve radiotherapy to the primary site and draining lymphatics while treatment for prostate cancer can also include pelvic radiotherapy. The literature is silent on the optimum course of action when these two malignancies are found synchronously or metachronously. Herein, we report a case of a patient diagnosed with intermediate risk prostate cancer who, prior to definitive therapy for this first malignancy, was also diagnosed with anal canal cancer. We conclude that a simultaneous approach with radiation therapy and chemotherapy with subsequent boost to the prostate is recommended. Screening for synchronous prostate cancer in male anal canal cancer patients is probably indicated and may preclude suboptimal treatment for a second occult primary.