The Value of Botox-A in Acute Radiation Proctitis: Results From a Phase I/II Study Using a Three-Dimensional Scoring System

Botulinum Toxin Treatment for Cancer-Related Disorders: A Systematic Review

This systematic review investigates the effect of botulinum neurotoxin (BoNT) therapy on cancer-related disorders. A major bulk of the literature is focused on BoNT's effect on pain at the site of surgery or radiation. All 13 published studies on this issue indicated reduction or cessation of pain at these sites after local injection of BoNTs. Twelve studies addressed the effect of BoNT injection into the pylorus (sphincter between the stomach and the first part of the gut) for the prevention of gastroparesis after local resection of esophageal cancer. In eight studies, BoNT injection was superior to no intervention; three studies found no difference between the two approaches. One study compared the result of intra-pyloric BoNT injection with preventive pyloromyotomy (resection of pyloric muscle fibers). Both approaches reduced gastroparesis, but the surgical approach had more serious side effects. BoNT injection was superior to saline injection in the prevention of esophageal stricture after surgery (34% versus 6%, respectively, p = 0.02) and produced better results (30% versus 40% stricture) compared to steroid (triamcinolone) injection close to the surgical region. All 12 reported studies on the effect of BoNT injection into the parotid region for the reduction in facial sweating during eating (gustatory hyperhidrosis) found that BoNT injections stopped or significantly reduced facial sweating that developed after parotid gland surgery. Six studies showed that BoNT injection into the parotid region prevented the development of or healed the fistulas that developed after parotid gland resection-parotidectomy gustatory hyperhidrosis (Frey syndrome), post-surgical parotid fistula, and sialocele. Eight studies suggested that BoNT injection into masseter muscle reduced or stopped severe jaw pain after the first bite (first bite syndrome) that may develop as a complication of parotidectomy.

Radiotherapy-Specific Chronic Pain Syndromes in the Cancer Population: An Evidence-Based Narrative Review

While radiation therapy is increasingly utilized in the treatment paradigm of many solid cancers, the chronic effects of radiation therapies are poorly characterized. Notably, understanding radiation-specific chronic pain syndromes is paramount given that the diagnosis and management of these conditions can serve to prevent long-standing functional impairments, optimize quality of life, and even allow for continued radiotherapy candidacy. These radiation-specific chronic pain phenomena include dermatitis, mucositis, enteritis, connective tissue fibrosis, lymphedema, and neuropathic pain syndromes. It is necessary to maintain a low threshold of suspicion for appropriately diagnosing these conditions as there exists a variance in when these symptoms arise after radiation. However, we present key epidemiological data delineating vulnerable cancer populations for each pain syndrome along with the available evidence for the management for each specific condition.

Botulinum Toxin Confers Radioprotection in Murine Salivary Glands

PURPOSE

Xerostomia is a common radiation sequela, which has a negative impact on the quality of life of patients with head and neck cancer. Current treatment strategies offer only partial relief. Botulinum toxins (BTX) have been successfully used in treating a variety of radiation sequelae such as cystitis, proctitis, fibrosis, and facial pain. The purpose of this study was to evaluate the effect of BTX on radiation-induced salivary gland damage.

METHODS AND MATERIALS

We used a previously established model for murine salivary gland irradiation (IR). The submandibular glands (SMGs) of C5BL/6 mice (n=6/group) were injected with saline or BTX 72 hours before receiving 15 Gy of focal irradiation. Saliva flow was measured 3, 7, and 28 days after treatment. The SMGs were collected for immunohistochemistry, confocal microscopy, and Western blotting. A cytokine array consisting of 40 different mouse cytokines was used to evaluate cytokine profiles after radiation treatment.

RESULTS

Irradiated mice showed a 50% reduction in saliva flow after 3 days, whereas mice preinjected with BTX had 25% reduction in saliva flow (P<.05). Cell death detected by TUNEL staining was similar in SMG sections of both groups. However, neutrophil infiltrate, detected by myeloperoxidase staining, was 3-fold lower for the BTX treated mice. A cytokine array showed a 2-fold upregulation of LPS-induced chemokine (LIX/CXCL5) 3 days after IR. BTX pretreatment reduced LIX levels by 40%. At 4 weeks after IR, the saline (control) group showed a 40% reduction in basal SMG weight, compared with 20% in the BTX group. Histologically, BTX-pretreated glands showed relative preservation of acinar structures after radiation.

CONCLUSIONS

These data suggest that BTX pretreatment ameliorates radiation-induced saliva dysfunction. Moreover, we demonstrate a novel role for CXCL5 in the acute phase of salivary gland damage after radiation. These results carry important clinical implications for the treatment of xerostomia in patients with head and neck cancer.

Systematic Review of the Relationship between Acute and Late Gastrointestinal Toxicity after Radiotherapy for Prostate Cancer

A small but meaningful percentage of men who are treated with external beam radiation therapy for prostate cancer will develop late gastrointestinal toxicity. While numerous strategies to prevent gastrointestinal injury have been studied, clinical trials concentrating on late toxicity have been difficult to carry out. Identification of subjects at high risk for late gastrointestinal injury could allow toxicity prevention trials to be performed using reasonable sample sizes. Acute radiation therapy toxicity has been shown to predict late toxicity in several organ systems. Late toxicities may occur as a consequential effect of acute injury. In this systematic review of published reports, we found that late gastrointestinal toxicity following prostate radiotherapy seems to be statistically and potentially causally related to acute gastrointestinal morbidity as a consequential effect. We submit that acute gastrointestinal toxicity may be used to identify at-risk patients who may benefit from additional attention for medical interventions and close follow-up to prevent late toxicity. Acute gastrointestinal toxicity could also be explored as a surrogate endpoint for late effects in prospective trials.

Use of injectable spasticity management agents in a cancer center

PURPOSE

This study aims to analyze the utilization and effectiveness of injectable spasticity medications by the physiatry team at a referral-based tertiary cancer center.

METHODS

A retrospective review and analysis of patient and injection characteristics were obtained from patients who had received onabotulinum toxin or phenol nerve block injections from December 1, 2007 through January 31, 2012. Out of 3,724 physiatry consultations during this period, 20 (less than 1 %) different cancer patients received a total of 54 total procedures.

RESULTS

The majority of patients (17/20, 85 %) had a positive response to the injection. A positive response to the injection was defined by: (1) if the patient qualified to receive and was given another injection or (2) if there is a record of improvement if they did not receive another injection. A total of ten of 20 (50 %) patients received only one injection. Of these, seven of ten (70 %) reported a positive response to the injected agent. Those with only one injection tended to live farther away and die sooner. Four of 54 (7 %) injection procedures resulted in undesirable reported side effects (two for phenol, two for botulinum toxin). Nine of 54 (17 %) procedures occurred while the patients were on a chemotherapy protocol. All patients were injected at least 1 year out from initial diagnosis.

OnabotulinumtoxinA for treatment of focal cancer pain after surgery and/or radiation

OBJECTIVE

To report the relief from refractory focal post-radiation and/or postsurgical cancer pain after local treatment with onabotulinumtoxinA.

SETTING AND DESIGN

We studied the effect of onabotulinumtoxinA in seven cancer patients who suffered from severe focal pain (visual analog scale >5) at the site of local surgery or radiotherapy or both. OnabotulinumtoxinA (20-100 units) was injected into the focal pain areas (skin or muscle or both). Five of seven patients were followed beyond 1 year (1.5-5 years) with repeat treatment.

RESULTS

All seven patients reported a significant improvement in pain (mean drop in visual analog scale score of 5.1). They described their response on the patient global assessment as satisfactory (two patients) or very satisfactory (five patients). Six of seven patients found the pain relief associated with significant improvement in quality of life. One patient developed weakness of jaw muscles after bilateral masseter injection that was not observed during second injection (reduced dose). Improvements with treatment persisted with repeat injections during long-term follow-up (five patients).

CONCLUSION

Local treatment with onabotulinumtoxinA can significantly reduce pain and improve quality of life in cancer patients suffering from pain in the area of surgery and radiation and was well tolerated in cancer patients.