C1 inhibitor deficiency: consensus document

We present a consensus document on the diagnosis and management of C1 inhibitor deficiency, a syndrome characterized clinically by recurrent episodes of angio-oedema. In hereditary angio-oedema, a rare autosomal dominant condition, C1 inhibitor function is reduced due to impaired transcription or production of non-functional protein. The diagnosis is confirmed by the presence of a low serum C4 and absent or greatly reduced C1 inhibitor level or function. The condition can cause fatal laryngeal oedema and features indistinguishable from gastrointestinal tract obstruction. Attacks can be precipitated by trauma, infection and other stimulants. Treatment is graded according to response and the clinical site of swelling. Acute treatment for severe attack is by infusion of C1 inhibitor concentrate and for minor attack attenuated androgens and/or tranexamic acid. Prophylactic treatment is by attenuated androgens and/or tranexamic acid. There are a number of new products in trial, including genetically engineered C1 esterase inhibitor, kallikrein inhibitor and bradykinin B2 receptor antagonist. Individual sections provide special advice with respect to diagnosis, management (prophylaxis and emergency care), special situations (childhood, pregnancy, contraception, travel and dental care) and service specification.

Pegylated interferon alpha-2a and -2b in combination with ribavirin in the treatment of chronic hepatitis C: a systematic review and economic evaluation

OBJECTIVES

To assess the clinical-effectiveness and cost-effectiveness of pegylated interferon-alpha combined with ribavirin in the treatment of chronic hepatitis C.

DATA SOURCES

Electronic databases, reference lists of retrieved reports, and the industry submissions to the National Institute for Clinical Excellence.

REVIEW METHODS

Sources were rigorously searched and studies were selected that met the inclusion criteria of being randomised controlled trials (RCTs) involving comparisons between pegylated interferon-alpha plus ribavirin and non-pegylated interferon plus ribavirin (two trials) or pegylated interferon alone and non-pegylated interferon alone (four trials). The primary outcome in all trials was sustained virological response (SVR) at follow-up. The trials were generally of good quality, although reporting of methodological details could have been more thorough in places. A cost-effectiveness model followed a hypothetical cohort of 1000 individuals with chronic hepatitis C over a 30-year period.

RESULTS

In the two trials that tested pegylated interferon plus ribavirin against non-pegylated interferon plus ribavirin the combined percentage of sustained virological response was 55%. The relative risk (RR) for remaining infected was reduced by 17% for pegylated interferon plus ribavirin compared with non-pegylated interferon plus ribavirin. Response to therapy varied according to viral genotype. Patients with genotype 1 had the lowest levels of sustained virological response and patients with genotype 2 or 3 had the highest. In the four trials that evaluated pegylated interferon monotherapy against non-pegylated interferon the combined sustained virological response rates were 31% for pegylated interferon and 14% for non-pegylated interferon. The RR for remaining infected with hepatitis C was reduced by 20% with the use of pegylated interferon. Patients with genotype 1 had the lowest levels of sustained virological response. There were also variations in sustained virological response according to other prognostic variables such as baseline viral load. Regimens involving pegylated interferon appear to be fairly well tolerated. Adverse events were been reported, but they did not differ substantially from levels of adverse events in regimens involving non-pegylated interferon. The incremental discounted cost per QALY for comparing no active treatment to 48 weeks of dual therapy with pegylated interferon and ribavirin (PEG + RBV) was 6045 pounds sterling. When moving from 48 weeks of dual therapy with non-pegylated interferon and ribavirin (IFN + RBV) to 48 weeks of dual therapy with PEG + RBV the figure was 12,123 pounds sterling. Subgroup analyses for dual PEG + RBV therapy demonstrated that the most favourable incremental discounted cost per QALY estimates were for patients infected with genotypes 2 and 3, and with low baseline viral load (3921 pounds sterling) compared with no active treatment. Results of one-way sensitivity analyses showed that the estimates varied according to differences in SVRs, drug costs and discount rates. In general estimates remained under 30,000 pounds sterling per QALY. The incremental discounted cost per QALY when moving from no active treatment to 48 weeks of monotherapy with pegylated interferon was 6484 pounds sterling. When moving from 48 weeks of monotherapy with IFN to 48 weeks of monotherapy with PEG the figure was 8404 pounds sterling. As with dual therapy, the lowest incremental cost per QALY was for patients with genotypes 2 and 3 and low baseline viral load, in the range 2641-4194 pounds sterling. The highest estimates were for patients with genotype 1 and high baseline viral load, around 30,000 pounds sterling.

CONCLUSIONS

Well-designed RCTs show that patients treated with pegylated interferon, both as dual therapy and as monotherapy, experience higher sustained viral response rates than those treated with non-pegylated interferon. Patients with genotypes 2 and 3 experience the highest response, with rates in excess of 80%. Patients with the harder to treat genotype 1 nevertheless benefit, with up to 46% of patients experiencing an SVR in one of the trials. Pegylated interferon also appears to be relatively cost-effective in both monotherapy and dual therapy, with cost per QALY estimates remaining generally under 30,000 pounds sterling. The most favourable estimates were for patients with genotypes 2 and 3. Pegylated interferon is a relatively new intervention in the treatment of hepatitis C and therefore there are areas where further research is needed. These include: efficacies of therapy with PEG-alpha-2a vs PEG-alpha-2b; retreatment of previous non-responders using pegylated interferon; efficacy of treatments and long-term outcomes in patients who have other co-morbidities; prospective tests of rules governing stopping treatment; treating patients with acute hepatitis C; problems that may occur in a minority of patients with hepatitis C, such as cryoglobulinaemia and vasculitis; additional psychological effects on quality of life due to hepatitis C and also on the treatment of children and adolescents with hepatitis C.

A patient with Rothmund–Thomson syndrome and tongue cancer — experience of radiation toxicity

We describe a male patient with Rothmund-Thomson syndrome (RTS) given postoperative radiotherapy for squamous carcinoma of the tongue. This was well tolerated. This is only the second reported case of oral cancer and radiotherapy in RTS.

Effectiveness and cost-effectiveness of imatinib for first-line treatment of chronic myeloid leukaemia in chronic phase: a systematic review and economic analysis

OBJECTIVES

To evaluate the effectiveness of imatinib as first-line treatment for chronic myeloid leukaemia (CML) compared with interferon-alpha (IFN-alpha), hydroxyurea and bone marrow transplantation (BMT), and the cost-effectiveness of imatinib compared with IFN-alpha and hydroxyurea.

DATA SOURCES

Electronic databases.

REVIEW METHODS

Selected studies and full-text articles were screened and rigorously selected. Survival was the key outcome measure. Surrogate outcome measures included haematological (blood) response and cytogenetic (bone marrow) response (CR). As no published cost-effectiveness studies were found that compared imatinib and IFN-alpha, an independent Markov model was constructed and this was compared with models submitted to the National Institute for Clinical Excellence by the manufacturer of imatinib.

RESULTS

Intention-to-treat analysis showed that imatinib was associated with complete CR at 12 months follow-up of 68% compared with 20% for the IFN-alpha plus Ara-C group. The estimated proportion of people taking imatinib who had not progressed to accelerated or blast phases at 12 months was 98.5%, and 93.1% for IFN-alpha plus Ara-C. Overall survival was not statistically significantly different. Withdrawal due to side-effects was 2% for imatinib and 5.6% for IFN-alpha plus Ara-C. Cross-over due to intolerance was 0.7% and 22.8% for imatinib and for IFN-alpha plus Ara-C, respectively. Quality of life was better in the imatinib group than the IFN-alpha group when assessed at 1, 3 and 6 months. Median survival across the four IFN-alpha versus hydroxyurea studies was 66 and 56.2 months, respectively. Median complete CR was 6% for IFN-alpha and 0 for hydroxyurea. Median withdrawal due to side-effects was 24% and 4% for IFN-alpha and hydroxyurea, respectively. Four out of the five studies comparing BMT and IFN-alpha showed a long-term survival advantage for BMT over IFN-alpha, but a short-term disadvantage. In four of the five studies comparing BMT and IFN-alpha, median survival had not yet been reached in the BMT groups in 6--10 years. Median survival in the IFN-alpha arms ranged from 5.2 to 7 years. The BMT group gained a survival advantage over IFN-alpha at 3--5.5 years. In the BMT group death due to transplant-related complications ranged from 36 to 45%. The incremental cost-effectiveness ratio (ICER) of imatinib compared with IFN-alpha from the independent model was GBP26,180 per quality-adjusted-life-years (QALY) gained and was relatively robust. Imatinib was less cost-effective than hydroxyurea with an ICER of GBP86,934.

CONCLUSIONS

Imatinib appears to be more effective than current standard drug treatments in terms of cytogenetic response and progression-free survival, with fewer side-effects. However, there is uncertainty concerning longer term outcomes, the development of resistance to imatinib, the duration of response and the place of imatinib relative to BMT. New issues are continually arising, such as optimal management pathways and combination therapies. Recommendations for research include: long-term follow-up data from the first- and second-line imatinib trials; investigation into specific subgroups, e.g. high-risk patients, the elderly, children or those eligible for BMT; long-term comparisons of imatinib with BMT performed in early stages of CML; the use of imatinib in combination with other therapies, and further detailed economic studies. Investigation of the impact of CML and imatinib on quality of life is also important.

In vivo measurement of total knee replacement wear

Polyethylene wear is one of the most important causes of failure of total knee replacements (TKRs). Currently, wear can only be accurately measured by retrieval studies. There is a need for a method to measure wear accurately in vivo. We have developed a Roentgen stereophotogrammetric analysis (RSA) system that can measure penetration of the metallic femoral component into the polyethylene of the tibia. We have used this system to study six AGC TKRs at 6 years postoperatively and six control AGC TKRs at 2 weeks postoperatively. The mean difference between the RSA measured bearing thickness and the manufacturer's quoted values for the control group was -0.03 mm (S.D. 0.17). The average linear penetration in the study group was 0.8 mm (S.D. 0.46). This was significantly (P<0.0001) different from the control group. The average linear penetration rate was 0.13 mm per year (S.D. 0.08). We would expect the penetration to deepen with time. In young active patients, this could be a cause for concern, particularly with a thin bearing. The current system is accurate enough to measure wear at 5 years post TKR. It has the potential for predicting long-term wear problems with new designs of TKR and new materials within 2 years.

The effectiveness and cost-effectiveness of microwave and thermal balloon endometrial ablation for heavy menstrual bleeding: a systematic review and economic modelling

OBJECTIVES

To estimate the clinical effectiveness and cost-effectiveness of microwave endometrial ablation (MEA) and thermal balloon endometrial ablation (TBEA) for heavy menstrual bleeding (HMB), compared with the existing (first-generation) endometrial ablation (EA) techniques of transcervical resection (TCRE) and rollerball (RB) ablation, and hysterectomy.

DATA SOURCES

Electronic databases, bibliographies of articles, and also experts in the field and relevant industry bodies were asked to provide information.

REVIEW METHODS

A detailed search strategy was carried out to identify systematic reviews and controlled trials of MEA and TBEA versus first-generation techniques for EA. In addition to electronic database searching, reference lists were hand-searched and information sought from manufacturers of EA devices and by experts in the field. A deterministic Markov model was developed to assess cost-effectiveness. Data for the model were taken from a range of sources.

RESULTS

The systematic review of first-generation EA techniques versus hysterectomy found that EA offered an alternative to hysterectomy for HMB, with fewer complications and a shorter recovery period. Satisfaction and effectiveness were high for both MEA and TBEA. Costs were lower with EA although the difference narrows over time. Second-generation EA techniques are an alternative treatment to first-generation techniques for HMB, and first-generation techniques are known to offer an alternative to hysterectomy. Although no trials of second-generation techniques and hysterectomy have been undertaken, it seems reasonable to assume that second-generation techniques also offer an alternative surgical treatment. Using the model to assess cost-effectiveness, costs were very slightly higher for MEA when compared to TBEA, and differences in quality-adjusted life-years (QALYs) were negligible. For MEA compared with transcervical resection of the endometrium (TCRE) and RB ablation, costs were slightly lower with MEA and MEA accrued very slightly more QALYs. Compared with hysterectomy, MEA costs less and accrues slightly fewer QALYs. For TBEA compared with TCRE and RB ablation, costs were lower with TBEA and TBEA accrued slightly more QALYs. Compared with hysterectomy, TBEA costs moderately less and accrues moderately fewer QALYs.

CONCLUSIONS

Overall, there were few significant differences between the outcomes of first- and second-generation techniques including bleeding, satisfaction and QoL measures and repeat surgery rates. Second-generation techniques had significantly shorter operating and theatre times and there appear to be fewer serious perioperative adverse effects with second-generation techniques and postoperative effects are similar. Compared with hysterectomy, TCRE and RB are quicker to perform and result in shorter hospitalisation and faster return to work. Hysterectomy results in more adverse effects and is more expensive, although the need for retreatment leads this difference to decrease over time. Satisfaction with hysterectomy is initially higher, but there is no significant difference after 2 years. The economic model suggests that second-generation techniques are more cost-effective than first-generation techniques of EA for HMB. Both TBEA and MEA appear to be less costly than hysterectomy, although the latter results in more QALYs. Further research is suggested to make direct comparisons of the cost-effectiveness of second-generation EA techniques, to carry out longer term follow-up for all methods of EA in RCTs, and to develop more sophisticated modelling studies. Further research is also recommended into HMB to establish health-state utility values, its surgical treatment, convalescence, complications of treatment, symptoms and patient satisfaction.

Cationic corticosteroid for nonviral gene delivery

Delivery of plasmid DNA for gene therapy often provokes an inflammatory response that reduces transgene expression. Cationic lipids for lipofection lack pharmacological activity despite the hydrophobicity of many drug candidates that could be exploited. We report a one-step synthesis of a water-soluble, dexamethasone-spermine (DS) cationic lipid that has potent gene transfer capability in confluent endothelial cells when used with the neutral lipid, dioleoylphosphatidylethanolamine (DOPE). In contrast, unconjugated mixtures of dexamethasone, spermine, and/or DOPE have essentially no gene transfer activity. DS retains partial corticosteroid character as quantified by the rapid translocation of glucocorticoid receptor to the nucleus and by dose-dependent transactivation from a glucocorticoid response element. DS has anti-inflammatory activity in vivo in the mouse thioglycollate model of inflammation. In a mouse lung model, DS:DOPE resulted in significantly less interferon-gamma production at Day 1 and elevated transgene expression at Days 1 and 7 postintranasal instillation compared to DC-Chol:DOPE (sterol:DOPE:phosphate molar ratio of 1:1:1). Cationic pharmacophores such as DS represent a new approach to gene delivery and localized therapy.

Endoscopic snare polypectomy for bleeding postinflammatory polyps

We describe a patient with ulcerative colitis and protracted rectal bleeding who had required several blood transfusions and who was unresponsive to medical therapy, whose symptoms resolved after endoscopic resection of multiple giant postinflammatory polyps. This case report highlights the fact that postinflammatory polyps can occasionally cause significant symptoms, such as rectal bleeding, and that in these circumstances careful endoscopic polypectomy can be performed safely and result in a significant improvement in symptoms over a prolonged period of follow-up.

Temozolomide in patients with advanced non-small cell lung cancer with and without brain metastases. a phase II study of the EORTC Lung Cancer Group (08965)

This study was performed to evaluate the activity of single-agent temozolomide in two groups of chemotherapy-naïve non-small cell lung cancer (NSCLC) patients, with (12 patients) and without (13 patients) brain metastases (BM). Patients in both groups were treated with temozolomide 200 mg/m(2)/day, administered orally for 5 consecutive days of a 28-day cycle. Treatment was continued for up to six cycles, disease progression or unacceptable toxicity. The median number of received cycles was only one in the group with and two in the group without BM, and early disease progression was the main reason for treatment discontinuation. Toxicity was moderate-in the group of patients with BM, the most frequently observed grade 3 or 4 side-effects included thrombocytopenia (17%), granulocytopenia (17%), lethargy (17%); other neurological (17%) and other genitourinary toxicity (17%). Patients without BM experienced anaemia (15%), thrombocytopenia (23%), nausea (15%) and lethargy (15%). This trial was designed according to Simon one-sample two-stage testing procedure and both groups of patients were assessed separately. No objective response was observed in either group and the study was closed after the first step of accrual with the conclusion of a lack of therapeutic activity of single-agent temozolomide in patients with stage IV NSCLC.

Lung cancer 5: state of the art radiotherapy for lung cancer

Radiotherapy has a key role in curative and palliative treatments of patients with lung cancer. Important advances are described in the technique of treatment delivery and its integration with chemotherapy.

Overexpression of type 2 iodothyronine deiodinase in follicular carcinoma as a cause of low circulating free thyroxine levels

Thyroid function is normally undisturbed in patients with thyroid carcinoma. We have identified three patients with large or widely metastatic follicular thyroid carcinoma who had a persistently increased ratio of serum T(3) to T(4) in the absence of autonomous production of T(3) by the tumor. To investigate the possibility of tumor-mediated T(4) to T(3) conversion, we assayed types 1 and 2 iodothyronine selenodeiodinase (D1 and D2) activity in a 965-g follicular thyroid carcinoma resected from one of these patients. The V(max) for D2 was 8-fold higher than in normal human thyroid tissue. Resection of this tumor, leaving the left thyroid lobe intact, normalized the serum T(3) to T(4) ratio. In two other patients, treatment with sufficient levothyroxine to suppress TSH was associated with a high normal T(3) and a subnormal free T(4) index. In one, concomitant administration of the D1 inhibitors, propylthiouracil and propranolol, did not decrease the elevated serum T(3) to T(4) ratio. These data illustrate that increased T(4) to T(3) conversion in follicular thyroid carcinomas, probably by D2, can cause a significant perturbation in peripheral thyroid hormone concentrations.

GLOB-1: a prospective randomised clinical phase III trial comparing vinorelbine-cisplatin with vinorelbine-ifosfamide-cisplatin in metastatic non-small-cell lung cancer patients

BACKGROUND

The standard doublet, vinorelbine-cisplatin, was compared with a triplet of vinorelbine-ifosfamide-cisplatin, in terms of survival, in patients with advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

From February 1998 to June 1999, 259 chemonaïve patients entered the study and were randomised to receive either vinorelbine-cisplatin (NP; vinorelbine 30 mg/m(2) on days 1, 8 and 15 with cisplatin 80 mg/m(2) on day 1) or vinorelbine-ifosfamide-cisplatin (NIP; vinorelbine 25 mg/m(2) on days 1 and 8, ifosfamide 3 g/m(2) on day 1 and cisplatin 75 mg/m(2) on day 1), with both regimens being repeated every 3 weeks. All patients had stage IV or relapsed disease and a performance score of 0 or 1.

RESULTS

The overall response rate was 34.6% for NP and 35.7% for NIP. Median and 1-year survival rates were 10.0 months and 38.4% for NP, and 8.2 months and 33.7% for NIP, respectively. A median of four cycles was administered in each arm. The major World Health Organization grade 3-4 toxicities for NP and NIP, respectively, were: neutropenia (20.3% compared with 9% of cycles), anaemia (4.1% compared with 5% of cycles), nausea and vomiting (22.2% compared with 19.4% of patients) and alopecia (5.6% compared with 29.8% of patients). Four toxic deaths occurred in the NP arm and eight in the NIP arm.

CONCLUSIONS

The different schedules of vinorelbine in the two arms led to a greater survival in the NP arm without impairing the tolerance profile, although this is not statistically significant. This confirms that the two-drug combination NP is a reference treatment for metastatic NSCLC. The role of three-drug combinations remains questionable in this subset of patients.

Propionibacterium acnes endocarditis in a native valve complicated by intraventricular abscess: a case report and review

Propionibacterium acnes is a constituent of the normal skin flora. It has been described as causing infection on prosthetic valves but very rarely on native valves. We describe a case of aggressive P. acnes endocarditis in a healthy 36-y-old man which infected a native aortic valve and was complicated by an aortic root abscess and review the literature.

A case of weak muscles

BACKGROUND

Gut involvement in inflammatory myositis is rare but causes significant morbidity and mortality.

CASE REPORT

A case of eosinophilic gastroenteritis and polymyositis occurring in the same patient is described. The interface of visceral and striated muscle involvement is discussed. The pathophysiology of eosinophilic gastroenteritis and the spectrum of gastrointestinal involvement in inflammatory myositis are also discussed.

RESULTS

Both gastrointestinal and skeletal muscle symptoms improved with immunosuppression, suggesting a possible common underlying mechanism.

The use of arthrocentesis for the treatment of osteoarthritic temporomandibular joints

PURPOSE

The purpose of this retrospective study was to determine the efficacy of arthrocentesis in restoring the functional capacity of osteoarthritic temporomandibular joints (TMJ).

PATIENTS AND METHODS

This study involved 36 patients (29 females, 7 males; age range, 16 to 54 years, mean, 37.36 +/- 14.60 years) presenting with 38 dysfunctional joints that had not responded to conservative treatment. The postarthrocentesis status (follow-up period 6 to 62 months, mean 20.7 +/- 20.5 months) of the TMJs was determined by patient self-evaluation using visual analog scales and clinical examination.

RESULTS

Of the 38 TMJs treated with arthrocentesis, 26 joints reacted favorably to the treatment; pain and dysfunction scores were reduced from 9.86 +/- 0.73 to 3.39 +/- 0.76 and from 11.34 +/- 0.66 to 3.4 +/- 0.69, respectively (P <.001). Self-assessed general improvement/deterioration was +4.90 +/- 2.10 (on a scale of -7 to +7). Maximal mouth opening increased from 24.40 +/- 2.70 mm to 43.20 +/- 3.10 mm (P <.001). Lateral and protrusive jaw movements also increased in magnitude. In 14 patients in whom no improvement was noted, arthrocentesis acted as a diagnostic tool before surgical treatment.

CONCLUSIONS

Arthrocentesis is a safe and rapid procedure that in many instances results in the osteoarthritic TMJs returning to a healthy functional state. Failure of arthrocentesis suggests that the painful limitation is most probably caused by changes such as fibrous adhesions or osteophytes that require surgical intervention for their removal.

Long-term survival in patients with non-small cell lung cancer treated with palliative radiotherapy

The aim of palliative thoracic radiotherapy in patients with advanced non-small cell lung cancer (NSCLC) is to alleviate symptoms. This study was designed to determine whether any patients achieved long-term survival after this treatment. In Edinburgh, between 1974 and 1993, 4531 patients were treated with palliative radiotherapy for NSCLC, receiving ten fractions or fewer. We reviewed the case notes of the long-term survivors. Sixty-one (1.3%; 95% confidence interval (CI) 1.0-1.6) patients survived for more than 5 years; 43 (70%) had histological confirmation of cancer; 28 (46%) had stage Stage I or II, 28 (46%) Stage III and one Stage IV disease; 53 (87%) patients were treated with doses of 30-35 Gy in ten daily fractions, seven (12%) received 20 Gy in five daily fractions and one received a 10 Gy single fraction. Forty-two (69%) patients had a radiological complete response, 16 (26%) a partial response and the remainder stable disease. Clinically significant radiation pneumonitis occurred in one (2%) patient, radiation myelopathy in two (3%) and multiple rib fractures in one (2%). There did not appear to be an association between long-term survival and a radiosensitive phenotype. On univariate analysis, long-term survival was more frequent in patients receiving ten-fraction regimens than in those who underwent a shorter course of radiotherapy (chi 2 = 19.5, P < 0.001). Thirty-four (0.8%; 95% CI 0.6-1.0) patients were disease free at death or at last review (median 10 years; range 5-17). We conclude that palliative thoracic radiotherapy produces long-term survival in 1.3% and personal cure in up to 1% of patients with advanced NSCLC.

Characterizing the phenomenon of radiation recall dermatitis

Radiation recall represents the 'recalling' of an effect similar in appearance to that of an acute radiation reaction in a previously irradiated field. The recall is triggered by the administration of certain drugs days to years after the exposure to ionizing radiation. This review focuses almost exclusively on the skin manifestations of radiation recall to assemble the largest data base upon which to discuss this rare phenomenon. No absolute radiation dose threshold is apparent, but rather an interplay between dose and time before drug exposure seems to affect both the risk and speed of onset of recall. Recall usually occurs on first exposure to a particular recall-triggering drug. The skin reaction develops within minutes to days. The time to develop the reaction may be slightly longer for oral than intravenously administered drugs reflecting their bioavailability. Most drugs associated with recall are cytotoxics, but several other drugs may elicit the phenomenon. Individuals exposed to a number of potentially recall-triggering drugs reveal the marked drug specificity characteristic of the phenomenon. Skin reactions usually settle within a few days of stopping the triggering drug. The role of steroids or anti-histamines in affecting resolution is unclear. Drug rechallenge tends to produce either only a mild recurrence or no recurrence of recall. Steroids or dose reduction may favour uneventful rechallenge. A number of aetiological hypotheses on radiation recall exist. Using the available evidence these hypotheses are critically reviewed and a novel hypothesis based on radiation affecting local cutaneous immunological responses proposed.