Selective internal radiation treatment for hepatic malignancy

The 2013 Alpine Liver and Pancreatic Surgery meeting was held in Madonna di Campiglio, Italy. The meeting was organised by the Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland. The following abstracts were selected for presentation at the meeting.

Radioactive waste discharge quantities for patients undergoing radioactive iodine therapy for thyroid carcinoma

There is a need to provide realistic estimates of the activity discharged to the drains by patients undergoing procedures involving unsealed radionuclides. These estimates are essential for record keeping purposes, to demonstrate compliance with limits set in waste disposal authorizations and for planning new installations. In this study, we report the discharge of activity for 174 patients (202 treatments) undergoing treatment of thyroid carcinoma with radioactive iodine. We have found that approximately 55% of administered activity is excreted in the first 24 h and that 85% of administered activity is discharged to the sewer over a typical inpatient stay of 5 days. There was no significant difference in levels of discharge between those patients undergoing inaugural ablation therapy and those having further treatments with radioactive iodine.

Co-induction and laryngeal mask insertion. A comparison of thiopentone versus propofol

Conditions for insertion of the laryngeal mask airway were assessed in 70 unpremedicated patients comparing the co-induction with midazolam-alfentanil-thiopentone and midazolam-alfentanil-propofol. Following pre-induction doses of midazolam 0.04 mg.kg-1 and alfentanil 10 micrograms.kg-1, patients received equipotent doses of either thiopentone or propofol. Whilst jaw relaxation and ease of laryngeal mask insertion were similar between the two groups, patients receiving propofol were less likely to have undesired responses requiring additional boluses of induction agent (p < 0.05). We conclude that, using these doses, propofol is superior to thiopentone for laryngeal mask airway insertion when using a co-induction technique.

Positive MIBG scanning at the time of relapse in neuroblastoma which was MIBG negative at diagnosis

Metaiodobenzylguanidine (MIBG) labelled with iodine-123 (123I) or 131I has become a well established tool with high sensitivity and specificity in the diagnosis and staging of neuroblastoma in children. However, some neuroblastomas do not take up MIBG at the time of diagnosis. The reasons for this are unclear but may be related to uptake mechanisms. Follow-up MIBG scans have not been reported in these patients. We present a case where an initial 123I-MIBG-scan was negative at diagnosis but became positive when the patient relapsed. This unusual occurrence may have implications for patients with a negative MIBG-scan at presentation. These patients should be re-evaluated by MIBG-scan at the time of relapse as a positive scan then offers the possibility of additional treatment with MIBG therapy.

Epidural bupivacaine/fentanyl infusions vs. intermittent top-ups: a retrospective study of the effects on mode of delivery in primiparous women

This study was designed to determine whether the introduction of epidural infusions containing fentanyl and bupivacaine has affected the mode of delivery in primiparous women attending our maternity department. We reviewed retrospectively the computerized records of 4362 consecutive primiparous women in labour. All the women were admitted with the expectation of a vaginal delivery. The results were analysed using logistic regression analysis adjusted for age, weight, gestation, cervical dilatation at epidural insertion, use of oxytocin, the year of entry into the study and the type of epidural block received. In women receiving an epidural block at 3-6 cm cervical dilatation (n = 1534), those who received an infusion were significantly less likely to have an emergency Caesarean section than those having intermittent 'topups' (P = 0.0019). In the same subgroup of women, the Caesarean section rate specifically for failure to progress followed the same trend, but just failed to reach statistical significance (P = 0.058). This provides evidence to support the theory that epidural infusions containing a low dose bupivacaine/fentanyl combination may reduce the risk of Caesarean section in primiparous women.

Interstitial photodynamic therapy. Clinical experience with diffusing fibres in the treatment of cutaneous and subcutaneous tumours

Interstitial photodynamic therapy has a number of potential advantages over superficial treatment. We have treated 50 subcutaneous and cutaneous tumours interstitially, in nine patients. An additional 22 tumours in the same patients, were treated by superficial PDT. Patients received 1.5-2.0 mg kg-1 of polyhaematoporphyrin and 72 h later underwent treatment using a copper vapour dye laser producing red light at 630 nm. All interstitial treatments were delivered using cylindrical diffusing fibres and a wide range of light doses (5-1500 J cm-3). The complete response rate for all tumours treated interstitially was 52%, rising to 81% in those patients who received 2.0 mg kg-1 PHP and light doses in excess of 500 J cm-3. The overall incidence of skin necrosis was 32% and was 79% in those treated with light doses of greater than 500 J cm-3. The incidence of skin necrosis with interstitial PDT is lower than that seen with superficial photodynamic therapy but higher volumetric light doses are required to produce tumour complete responses. All treatments were well tolerated and volumes of tumour up to 60 cm3 were successfully treated. The penetration depth of 630 nm light in human breast cancer tissue was determined as 4 mm. Little true tumour tissue selectivity was detected by analysis of porphyrin levels in biopsy material.

In vivo measurement of the optical interaction coefficients of human tumours at 630 nm

The light distribution within a treatment volume is determined by the source geometry (e.g. superficial or interstitial illumination) and the optical interaction coefficients of the irradiated tissue. We have measured the energy fluence rate at various points within tumours undergoing irradiation with 630 nm light for photodynamic therapy for several source geometries. The relative positions of source and detector fibres were determined using CT scanning techniques. The results of the measurements were then applied to solutions of the diffusion theory which allowed the determination of the absorption coefficient (sigma a = 30.5 +/- 16 m-1), the reduced scattering coefficient (sigma' s = 941 +/- 735 m-1), the effective attenuation coefficient (sigma eff = 261 +/- 49 m-1) and the build-up coefficient which relates surface irradiance to the energy fluence rate at depth (k = 1.6 +/- 0.6). Knowledge of these coefficients allows the transmission of light through tissue to be predicted and hence the optical dosimetry of subsequent treatments to be planned more effectively.

The effect of surface finish on the reflection of CO2 laser beams from specula

A potential source of hazard during gynaecological surgery with a CO2 laser is the reflection of the laser beam from the surfaces of the metal speculum. An experimental method of measuring the levels of radiation reflected from a variety of surfaces is described. Results which compare the effectiveness of different surface treatments in reducing reflections and show how this varies over a range of angles of incidence are presented. The significance of the results in terms of hazards to patients and staff is discussed.