Recall Reactions Research Articles

Recognizing cisplatin as a potential radiation recall trigger: case report and focused systematic review

We present a case of mild radiation recall dermatitis triggered by cisplatin chemotherapy given simultaneously to re-irradiation. The dermatitis area correlated to skin exposure of the previous radiation therapy, characterizing the reaction clearly as a recall. Cisplatin has not yet been recognized as a potential trigger for recall reactions. Although it was part of several reported multidrug trigger combinations, all review works referred to cisplatin as not suspicious, suggesting the combination partner as the effector. We performed a focused systematic literature review aiming to re-evaluate the real role of cisplatin as a (co-)triggering factor. In total, 30 reported cases were found, 90% triggered by multidrug combinations. The latter tended to cause more severe symptoms. Besides findings supporting the 20 Gy-threshold theory, no correlation between radiation dose and severity or prevalence was found. Recognition of cisplatin as a trigger of the recall phenomenon and its supportive management may prevent unnecessary cessation of systemic chemotherapy. Systematic reporting of recall events as a secondary endpoint of prospective clinical trials applying radiation therapy could support understanding the recall phenomenon.

Drug-induced radiation recall reactions and non-anticancer drugs: A descriptive analysis from VigiBase®.

Radiation recall reactions are inflammatory reactions confined to previously irradiated tissues, often of drug-induced etiology, particularly with anticancer therapies. Other drugs, in particular COVID-19 vaccines, may also be involved. To describe radiation recall reactions under non-anticancer drugs more precisely, we extracted the cases of radiation recall reactions associated with non-anticancer drugs from WHO pharmacovigilance database VigiBase®. We performed two analyses from this extraction: a global analysis and an analysis focusing on vaccination-related issues. We extracted 120 cases corresponding to 269 drugs, of which 130 were non-anticancer (22 vaccines). Among the non-anticancer drugs, tozinameran was the most reported treatment (4.46% of cases), followed by levofloxacin (2.97%) and folinic acid (2.60%), dexamethasone (2.23), and ChAdOx1 nCoV-19 vaccine and prednisone (1.86% each). Among vaccines, tozinameran (54.55% of cases) was the most reported, followed by ChAdOx1 nCoV-19 (22.73%), HPV and inactivated influenza vaccine (9.09% each), and elasomeran (4.55%). Our study first describes the occurrence of radiation recall reactions during non-anticancer treatment. It also highlights a potential safety signal with COVID-19 vaccines.

Characteristics of Aboriginal and Torres Strait Islander smokers exposed to anti-smoking marketing in South Australia

ABSTRACT Background Smoking is disproportionately prevalent among Aboriginal and Torres Strait Islander Australian peoples, with 39% of Indigenous Australians aged over 15 years smoking daily. Efforts to reduce the prevalence include culturally focused media campaigns, designed through community consultation, that highlight the need to determine how such health messaging is perceived by smokers. This study aimed to examine Indigenous Australian smokers’ reactions to a culturally focused anti-smoking mass media campaign. Methods Intercept surveying across health services and events recorded demographics, smoking status, quit attempts, smoking health effects, anti-smoking campaign recall, social support, and campaign reactions. Participants rated four different campaign images in five domains: (1) whether it made them stop and think; (2) personal relevance; (3) believability of design and message; (4) prompting concern about smoking; and (5) motivation towards quitting. Cluster analysis was used to identify smoker types. Results Smoking health effects knowledge was high, and did not differ by quit readiness, attempts, or social support. Cessation support access was higher among those with greater readiness to quit. Social smoking behaviour and confidence to support others quitting did not significantly differ between participants, however importance of others quitting did. Quit readiness, attempts, and social support were associated with reaction to campaign design, but not message recall. Four types of smokers were identified using smoking characteristics, who differed in campaign message reactions. Conclusions Culturally focused anti-smoking media can benefit from exploring how smoker types can be used to differentiate messaging by smokers’ profile characteristics, to support mass media smoking cessation efforts.

Sociodemographic, clinical profile, and treatment characteristics of oncology patients developing radiation recall phenomenon: Two tertiary care center's experience of an eternal unpredictable phenomenon of cancer treatment.

ABSTRACTObjectives:To determine the socio-demographic and clinical profile of cancer patients developing radiation recall phenomenon or radiation recall dermatitis following chemotherapy administration, previously treated with external irradiation. We assessed its incidence, severity, frequency, differentiation from radio-sensitization and radiation-dermatitis, its correlation with radiation dose and chemotherapeutic agent, and various parameters affecting its occurrence.Materials and Methods:This observational prospective study was designed for 1092/2676 (50.2%) patients of histologically proven carcinoma breast, carcinoma lung, lymphomas, chest wall sarcomas, thymomas, thymic carcinomas, nasopharyngeal cancer, bladder carcinoma, rectal cancer, and metastatic cases who received radiation therapy followed by chemotherapy. Intake, treatment, observation, and follow-up were done from July 2014 to July 2021 for 7 years in two tertiary care cancer institutes of government setup.Results:In our study, majority of recall phenomena were reported in breast carcinoma 43/71 (60.5%) followed by carcinoma esophagus with 07/71 (9.8%) cases. Females developed 54.9% grade-I/II and 90% grade-III/IV recall cases compared to males with 45.1% and 10% cases, respectively (P = 0.005). Median radiation dose used was 45 Gy (dose range 8–70 Gy) (P = 0.656). Docetaxel resulted in 55% recall cases followed by paclitaxel with 12.7% of cases. Combination therapy reported 71.8% of cases compared to monotherapy with 28.2% of cases. Recall-cases recorded in the time period of 3–4 weeks between radiation and chemotherapy were 59/71 (83%) and those reported in >4 weeks were 12/71 (17%). Time-gap between 3 and 4 weeks reported 49% grade-I/II and 100% grade-III/IV recall-cases while time-gap >4 weeks resulted in 26% and 0% cases respectively (P = 0.000).Conclusion:In this study, taxanes and platinum-agents were the most common chemotherapeutic drugs involved in the occurrence of the recall phenomenon. Multi-drug regimens resulted in higher recall cases compared to monotherapy. Radiation dosage did not cause any significant impact. The risk and severity of recall reactions increased with female gender and shorter time-interval between radiation and systemic therapy, while early-onset recall cases displayed greater severity. This precedented but unpredictable phenomenon ceases to be a topic to be discarded in this modern era of highly conformal radiation therapy techniques and targeted cancer therapy.

Radiation recall reactions: An oncologic enigma.

Radiation recall reactions (RRR) are uncommon but are a well-known phenomenon to oncologists. Tissue damage in a prior irradiation portal is 'recalled' after the administration of a drug, historically cytotoxics, or more recently, targeted or immunotherapeutic agents. Even COVID-19 vaccines are a reported cause. RRR are enigmatic in that their cause is unknown, but they generally have the histopathological and clinical features of acute or chronic inflammation. They can occur in a variety of tissues, the commonest being skin, which accounts for two-thirds of reported cases. They are generally relatively mild and self-limiting once the trigger drug is stopped, although severe cases with tissue necrosis have occurred. Rechallenge with drug does not necessarily cause reactivation of the reaction. Symptomatic treatment with steroids and antihistamines are usually effective, but their impact on the clinical course is unclear. Various hypotheses have been proposed as to the mechanism of RRR; a non-immune fixed drug reaction-like condition, dysregulated release of reactive oxygen species, abnormalities of tissue vasculature and impaired DNA repair. All could lead to a characteristic inflammatory microenvironment, resulting in dysfunction of tissue stem cells, keratinocyte necrosis and dermal abnormalities. Alternatively or in addition, low levels of inflammatory tissue cytokines induced by previous irradiation might be further upregulated by drug exposure. Most information in this review refers to data derived from cutaneous RRR, since they are the most common form reported.

Cutaneous chemotherapy-induced radiation recall reaction.

Chemotherapy‐induced radiation recall reactions are rare, commonly affecting skin but can affect internal organs. Treatments include antihistamines and topical steroids and discontinuation of therapy if severe. Rechallenge may not cause recurrence.

Radiation Recall Pneumonitis After Treatment With Checkpoint Blockade Immunotherapy: A Case Series and Review of Literature.

BackgroundRadiation recall pneumonitis (RRP) is a poorly understood clinical syndrome in which patients develop radiation pneumonitis triggered by a systemic agent, often years after the completion of radiation therapy. Immune checkpoint blockade agents have only recently been posited as a trigger for RRP. Here, we present three cases of immunotherapy-induced RRP.Case PresentationOur first patient was diagnosed with primary lung adenocarcinoma, and 4.5 years after completing radiation therapy developed symptomatic RRP immediately following a second dose of nivolumab-containing immunotherapy regimen. Our second patient was diagnosed with primary bladder cancer metastatic to the mediastinum, which was treated twice with radiation therapy. He developed RRP in the days following his second course of ipilimumab-pembrolizumab which was months after his second course of radiation that he received. Our final patient was diagnosed with metastatic small cell lung cancer and received local consolidative radiation therapy in addition to whole-brain radiation. He developed RRP on the 11th day after concluding his 4th cycle of nivolumab-ipilimumab, approximately 7 months after having had completed chest radiation therapy.ConclusionsImmunotherapy-induced RRP is a rare diagnosis which can present more focally than traditional immunotherapy pneumonitis and which must be clinically differentiated from other local processes such as pneumonia. Further research should explore the mechanisms underlying these radiation recall reactions as many patients receive radiation and immunotherapy during the course of their cancer treatment.

“Radiation Recall Phenomenon” with Novel Cytotoxic Agents: An Emerging Trend in the Last Decade

AbstractRadiation recall phenomenon (RRP) is an acute inflammatory reaction manifested in the previously irradiated tissues after the administration of various pharmacologic compounds. While skin manifestations are the most common clinical features, patients may also present with visceral recall events including pneumonitis, hematuria, myopathy, and mucositis if any particular organ was exposed to the prior radiation portals. This article has reviewed the published case reports, case series, abstracts, and poster presentations in the past 10 years in any language on RRP caused by various novel cytotoxic drugs including immunotherapies, molecularly targeted agents, and unconventional chemotherapies. We retrieved the data through the literature search of MEDLINE and PubMed using the keywords “radiation,” “recall,” “targeted therapy,” and “immunotherapy,” and references identified in retrieved articles were also used for further search of the literature. With the increasing use of unconventional, novel cytotoxic agents and targeted molecules, concurrent or sequentially with radiation, we expect more incidences of RRP in future that may present with either dermatological or visceral recall reactions.

NK Cell-Mediated Recall Responses: Memory-Like, Adaptive, or Antigen-Specific?

Mounting experimental evidence hints to an import role for natural killer (NK) cells in adaptive immune responses to pathogens. NK cells with adaptive features are heterogeneous and belong to different subsets according to their phenotype as well as the nature of their adaptive recall reactions. Three types of adaptive NK cell responses have been described: (i) NK cells with long-lived memory of multiple different haptens and viral antigens were described in murine liver tissue with a possible human counterpart; (ii) infection of human and mouse cytomegalovirus is associated with an expansion of NKG2C+ and Ly49H+ NK cells, respectively, that selectively recognize CMV-encoded peptides thereby facilitating recall responses; (iii) cytokine-stimulated NK cells respond to different stimuli with enhanced production of IFN-γ after re-stimulation. These exciting findings not only support the idea of NK cells with adaptive features, but define a novel field of harnessing memory NK cell subsets for therapeutic strategies.

Phase I (safety assessment) of durvalumab (MEDI4736) with focal sensitizing radiotherapy in platinum resistant ovarian, primary peritoneal or fallopian tube epithelial carcinoma.

TPS5604 Background: Radiation (RT) of malignant neoplasms can induce immunogenic tumor cell death, alter the tumor micro-environment and enhance recruitment of anti-tumor T cells. Co-administration of focal RT and an immune checkpoint-inhibiting agent may overcome immune-suppressive signals and potentiate systemic responses. A phase I study is underway to assess the safety of RT combined with PD-L1 inhibition in patients with recurrent epithelial ovarian/fallopian tube/peritoneal carcinomas (OV). Methods: Women with platinum resistant epithelial OV, ECOG PS 0/1 and ≤ 2 lines of treatment in the platinum-resistant setting are eligible. 1 lesion evaluable by RECIST criteria (v 1.1) and 2 additional lesions suitable for RT (minimal treatment volume 4cc) are required. Pre- and on-treatment biopsies for correlative studies are mandatory. The primary objectives are to assess the safety and tolerability of the focal RT combined with the immune checkpoint inhibitor, durvalumab (D), as defined by dose-limiting toxicities (DLTs), and to define the maximum tolerated RT dose and treatment schedule. The secondary objectives are to evaluate the clinical activity of focal RT and D [RECIST (v 1.1), GCIG CA-125, and immune-related response criteria], progression free survival and overall survival. D 1500 mg delivered intravenously every 28 days = one cycle. RT to the 2 selected target lesions is delivered 24-36 hours prior to the infusion of D. The RT starting dose-level is 24Gy (in 4 fractions) per lesion (given Days -1, 1 and 28 of Cycle 1 and Day 1 of Cycle 2). A 3+3+3 design will permit more extensive exploration of toxicity if DLTs are observed (Table). Investigator assessed DLTs are defined by CTCAE v. 4.03 and include the following: any grade ≥3 adverse event suspected to be related to D or RT (necrosis or recall reactions at previously irradiated sites, RT induced bowel perforation, any unexpected grade 3 or greater toxicity at the site of RT), any grade ≥2 allergic or autoimmune event that involves vital organ function, and any other grade 3 allergic or autoimmune events that do not resolve to grade 1 before the next scheduled dose of D. Treatment may continue up to 12 months. Enrollment began August 2018. To date, no DLTs have been observed at dose level 1 (n= 3) and enrollment is ongoing. Clinical trial information: NCT03283943. [Table: see text]

262 Intravenous Ketamine: A Safe and Effective Option for Burn Wound Care

Very little has been published regarding the safety and efficacy of intravenous (IV) ketamine for burn wound care in adult patients. With increasing attention focused on the adverse effects of opioids, ketamine may serve as a safe sedative and analgesic during wound care and lower the incidence of post-traumatic stress disorder (PTSD) after burn injury. The purpose of this study was to characterize the use of IV ketamine during burn wound care and establish its potential role as a safe and effective adjunct to opioid and benzodiazepine medications. A retrospective review was conducted of adult patients admitted to a regional burn center who received IV ketamine for dressing changes or minor procedures such as skin substitute placement between September 2015 and July 2016. The burn intensive care unit attending administered all IV ketamine doses, and vital signs were monitored every 15 minutes during the procedure. Patient demographics including burn size (percent total body surface area - %TBSA) were recorded. Other data collected included type and duration of procedure and dosages of ketamine, opioid and benzodiazepine. Ketamine-related side effects including hypertension (systolic blood pressure > 200), recall, and dysphoric reactions were also collected. Cardiopulmonary complications such as aspiration, unplanned need for intubation, and myocardial infarction were tracked. A total of 50 patients met inclusion criteria. The mean patient age was 40 ± 15 years with an average burn size of 22 ± 24% TBSA. The mean dose of IV ketamine administered was 1.7 ± 1.2 mg/kg. Length of procedure was noted to be 40 ± 18 minutes. The majority of patients received IV midazolam (98%) at a mean dose of 3.6 ± 2.0 mg. Narcotics were administered to 13 patients (26%) at an average morphine equivalent dose of 14 ± 13 mg. Forty-six (92%) patients denied recall of their wound care. Three patients (6%) experienced a dysphoric reaction. Ketamine-induced hypertension was documented in 3 patients (6%) and all immediately responded to treatment with low-dose labetalol. No cardiopulmonary complications were noted. These findings suggest IV ketamine provides a safe analgesia and sedative option for burn wound care, even for patients with larger burn size in the intensive care unit setting. Patients in this study tolerated ketamine with minimal adverse effects and very few had recall of their wound care. As the growing epidemics of post-burn PTSD and opioid dependence are addressed, IV ketamine for burn wound care warrants further study. Intravenous ketamine is a safe and effective sedative-analgesic agent for utilization in burn wound care.

Normal Plasma Cell Biology: Natural Achilles Heels as Targets in Myeloma

Normal Plasma Cell Biology: Natural Achilles Heels as Targets in MyelomaÊ Primary exposure to antigen leads to affinity maturation, selection and terminal differentiation of mature B cells to antibody-secreting plasma cells. Long-lived high-affinity plasma cells and their immediate precursors reside in the bone marrow and are responsible for rapid recall reactions and a life-time production of high affinity antibodies. Members of the IKAROS gene family have been specifically implicated in the generation of long-lived plasma cells. Mice deficient for Aiolos, the B cell specific member of the IKAROS gene family fail to produce high affinity plasma cells in the bone marrow and to sustain serum antibody titers after both primary or secondary immunization with a range of hapten concentrations. Chimera reconstitutions have demonstrated that the bone marrow plasma cell defect is B cell intrinsic. However, lack of AIOLOS does not alter expression of any of the previously described factors required for B cell differentiation into the plasma cell stage. No defect in somatic hyper-mutation, the generation of memory B cells, or short-lived high affinity plasma cells in the spleen is observed upon challenge or re-challenge. Thus this IKAROS family member is critically required for high-affinity bone plasma cells possibly by regulating their interaction with the bone marrow microenvironment, a process that is likely critical for long-term survival. High-affinity bone marrow plasma cells are the normal counterpart of the devastating B cell malignancy multiple myeloma. Multiple myeloma is treatable with immune modulatory drugs (IMiD) such as lenalidomide. Recent studies have shown that IMiD alter the specificity of the CRL4-CEREBLON (CRL4CRBN) E3 ubiquitin ligase complex. Among the new targets for the CRL4CRBN complex are two of the IKAROS family members, AIOLOS and IKAROS, whose degradation adversely affects the cellular fitness of multiple myeloma cells. Recent studies in B cell precursors have implicated the IKAROS gene family in the regulation of bone marrow stromal interactions. IKAROS and AIOLOS activities balance self-renewal, survival, and pre-B cell differentiation by engaging epigenetic and transcriptional machineries through discrete lineage-specific superenhancers. Such AIOLOS and IKAROS-dependent regulatory pathways engaged in early B cell precursors may also be involved in controlling bone marrow stromal interactions with high affinity plasma cells and their malignant counterparts thereby contributing to long-term growth and survival. Further exploitation of IKAROS family-targeted pathways in bone marrow plasma cells and multiple myeloma is warranted. DisclosuresNo relevant conflicts of interest to declare.

Do Measures of Posttrauma Factors Better Explain PTSD Severity Than Pretrauma Factors? An Empirical Reply to Ogle et al. (2016)

Ogle, Rubin, and Siegler (2016) concluded that postevent risk factors account for PTSD symptomatology much better than pretrauma factors. However, in their study several postevent predictors such as involuntary recall and physical reactions to trauma memory were related to and assessed simultaneously with PTSD symptomatology. Removing content-related items from the PTSD measure would, according to the authors, ensure that results were not being driven by potential content overlap. In the present prospective study ( N = 887) we test their assumption that removing such items prevents that results are overlap driven. Correlational and multiple regression analyses showed that the associations between pre-event mental health and neuroticism on the one side and PTSD symptomatology on the other were equal regardless of if and which symptom cluster of PTSD was removed from our PTSD measure. Based on these findings we conclude that Ogle et al.’s assumption needs to be rejected.

P.2.a.009 - Visuospatial planning in unmedicated major depressive and bipolar disorder: distinct and common neural correlates

This study analyzed in vivo antiviral cellular immune reactions in the Shope rabbit papilloma – carcinoma model. Antigens studied in experimentally infected domestic rabbits were cottontail rabbit papillomavirus particles produced with the athymic (nu/nu) mouse xenograft system and bacterial fusion proteins containing the major or minor capsid protein. Recall reactions to antigens were tested by classic intracutaneous tests. Positive reactions had a biphasic course. Histopathology of skin test biopsy specimens showed infiltrating polymorphonuclear cells during the early stages. Later they were replaced by predominantly perivascular infiltrates composed of mononuclear cells. Time course of swelling and infiltrates resembled a delayed-type hypersensitivity reaction. Ten of 11 regressor rabbits (p = 0.00006) and 10 of 20 progressors (p = 0.009) had positive skin tests with intact and/or denaturated virus particles and individual capsid proteins also could elicit specific skin reactions. Skin reactivity to the cottontail rabbit papillomavirus particles was also greater (p = 0.042) in regressor rabbits (8 of 11) when compared to progressors (7 of 20). Recall reactions remained detectable at post-regression times, ranging from several months up to more than 2 years. We conclude that specific skin reactions against the cottontail rabbit papillomavirus in infected domestic rabbits exist, and are strongly positive to intact particles of this papillomavirus in animals (regressors) clinically free of disease.

Clinical management of etanercept recall reactions: A case report and review of the literature

Clinical management of etanercept recall reactions: A case report and review of the literature

Gemcitabine-Induced Pseudocellulitis in a Patient With Recurrent Lymphedema

Gemcitabine is a chemotherapeutic agent used for treatment of a variety of malignancies. It has been associated with multiple cutaneous reactions including rash, alopecia, and pruritus. Less commonly, gemcitabine has been associated with "pseudocellulitis," a noninfectious skin inflammatory reaction, which resembles cellulitis. The majority of cases reported in the literature are radiation recall reactions in which inflammation occurs in areas of previous radiation post drug treatment; however, there are also reports of pseudocellulitis occurring in areas of preexisting lymphedema. The pathophysiology of both of these reactions are still unknown, though it is theorized that areas of lymphedema may both increase concentration of gemcitabine and reduce its rate of metabolism leading to increased drug exposure time. In this study, we report a case of pseudocellulitis in a patient with chronic lower extremity lymphedema and a review of the current literature. By recognizing this side effect of gemcitabine, one can avoid unnecessary hospitalization and exposure to antibiotics.

Radiation recall reaction: two case studies illustrating an uncommon phenomenon secondary to anti-cancer agents.

Radiation recall phenomenon is a tissue reaction that develops throughout a previously irradiated area, precipitated by the administration of certain drugs. Radiation recall is uncommon and easily neglected by physicians; hence, this phenomenon is underreported in literature. This manuscript reports two cases of radiation recall. First, a 44-year-old man with nasopharyngeal carcinoma was treated with radiotherapy in 2010 and subsequently developed multi-site bone metastases. A few days after the docetaxel-based chemotherapy, erythema and papules manifested dermatitis, as well as swallowing pain due to pharyngeal mucositis, developed on the head and neck that strictly corresponded to the previously irradiated areas. Second, a 19-year-old man with recurrent nasal NK/T cell lymphoma initially underwent radiotherapy followed by chemotherapy after five weeks. Erythema and edema appeared only at the irradiated skin. Both cases were considered chemotherapeutic agents that incurred radiation recall reactions. Clinicians should be knowledgeable of and pay attention to such rare phenomenon.

Esophageal Toxicity From High-Dose, Single-Fraction Paraspinal Stereotactic Radiosurgery

To report the esophageal toxicity from single-fraction paraspinal stereotactic radiosurgery (SRS) and identify dosimetric and clinical risk factors for toxicity. A total of 204 spinal metastases abutting the esophagus (182 patients) were treated with high-dose single-fraction SRS during 2003-2010. Toxicity was scored using the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 4.0. Dose-volume histograms were combined to generate a comprehensive atlas of complication incidence that identifies risk factors for toxicity. Correlation of dose-volume factors with esophageal toxicity was assessed using Fisher's exact test and logistic regression. Clinical factors were correlated with toxicity. The median dose to the planning treatment volume was 24 Gy. Median follow-up was 12 months (range, 3-81). There were 31 (15%) acute and 24 (12%) late esophageal toxicities. The rate of grade ≥3 acute or late toxicity was 6.8% (14 patients). Fisher's exact test resulted in significant median splits for grade ≥3 toxicity at V12 = 3.78 cm(3) (relative risk [RR] 3.7, P=.05), V15 = 1.87 cm(3) (RR 13, P=.0013), V20 = 0.11 cm(3) (RR 6, P=0.01), and V22 = 0.0 cm(3) (RR 13, P=.0013). The median split for D2.5 cm(3) (14.02 Gy) was also a significant predictor of toxicity (RR 6; P=.01). A highly significant logistic regression model was generated on the basis of D2.5 cm(3). One hundred percent (n = 7) of grade ≥4 toxicities were associated with radiation recall reactions after doxorubicin or gemcitabine chemotherapy or iatrogenic manipulation of the irradiated esophagus. High-dose, single-fraction paraspinal SRS has a low rate of grade ≥3 esophageal toxicity. Severe esophageal toxicity is minimized with careful attention to esophageal doses during treatment planning. Iatrogenic manipulation of the irradiated esophagus and systemic agents classically associated with radiation recall reactions are associated with development of grade ≥4 toxicity.

Radiation Recall with Anticancer Agents

Radiation recall is an acute inflammatory reaction confined to previously irradiated areas that can be triggered when chemotherapy agents are administered after radiotherapy. It remains a poorly understood phenomenon, but increased awareness may aid early diagnosis and appropriate management. A diverse range of drugs used in the treatment of cancer has been associated with radiation recall. As most data come from case reports, it is not possible to determine the true incidence, but to date the antineoplastic drugs for which radiation recall reactions have been most commonly reported include the anthracycline doxorubicin, the taxanes docetaxel and paclitaxel, and the antimetabolites gemcitabine and capecitabine. Radiation recall is drug-specific for any individual patient; it is not possible to predict which patients will react to which drugs, and rechallenge does not uniformly induce a reaction. There are no identifiable characteristics of drugs that cause radiation recall, and thus, it is a possibility that must be kept in mind with use of any drug after radiotherapy, including those from new drug classes. Although it is not yet possible to design treatment regimens to eliminate the risk of radiation recall, it seems likely that risks can be minimized by prolonging the interval between completion of radiotherapy and initiation of chemotherapy.

Radiation Recall Dermatitis with Azithromycin

Radiation recall is a well-known phenomenon that involves the "recall" of an acute inflammatory reaction in a previously irradiated region after administration of certain drugs. The most common type of radiation recall is radiation recall dermatitis, which involves the reoccurrence of an acute inflammatory skin reaction in previously irradiated skin. Most radiation recall reactions are attributable to chemotherapeutic agents. One previously reported case of radiation recall dermatitis occurred after administration of an antibiotic. The present case report is the second of radiation recall dermatitis involving an antibiotic: azithromycin.