Assessment of Upfront Selection Criteria to Prioritise Patients for Breath-hold Left-sided Breast Radiotherapy.

AIMS: Deep inspiratory breath-hold (DIBH) techniques for left breast and chest wall radiotherapy can reduce cardiac dose. We investigated the use of 'upfront selection' criteria for DIBH based on tumour bed position and whether cardiac shielding was used. MATERIALS AND METHODS: Four methods of selecting patients for DIBH were assessed retrospectively in a cohort of left breast and chest wall treatments. These were: (1) free breathing scan on all patients, selecting DIBH treatment for those with a predicted mean heart dose ≥3 Gy; (2) selective DIBH for those with maximum heart depth (MHD) on free breathing scan ≥1 cm; (3) use of an 'upfront selection process' using tumour bed position as initial selection and measurement of MHD on those not selected upfront; (4) DIBH on all. The methods were assessed on predicted mean heart dose, proportion needing two scans, sensitivity, specificity and the positive and negative predictive values. These were compared with method (1) as the gold standard. RESULTS: In total 134 cases were analysed. The predicted mean heart dose in free breathing was ≥3 Gy in 28 (20.9%). Therefore, applying method (1), 28/134 (20.9%) would be selected for DIBH treatment. Applying method (2), 66/134 (49.2%) would be selected for DIBH treatment, all requiring two scans. Of these, 40/66 (60.6%) would receive < 3 Gy in free breathing so are over-selected; 2/68 (2.9%) would have received >3 Gy in free breathing so failed to be selected. Selection using method (3) was similar to method (2), but only five patients required two planning scans; 61/134 (45.5%) cases would be selected for DIBH upfront and 5/134 (3.7%) after initial free breathing scan; 42/66 (63.6%) of those selected for DIBH treatment would receive <3 Gy in free breathing and 4/68 not selected (6%) would receive >3 Gy in free breathing. For methods (2) and (3) most patients not selected for DIBH would have had a mean heart dose of ≤3 Gy (64/68, 90%). Using method (3), 86% (95% confidence interval 67-96%) of patients with a mean heart dose >3 Gy would be selected for DIBH treatment. The estimated mean and standard error for the area under the receiver operator characteristic curve for MHD as a predictor for mean heart dose was 0.85 (0.03). CONCLUSION: This study supports the use of proposed an 'upfront selection process' as a means of selecting patients for treatment with DIBH and avoiding two radiotherapy planning scans. Calculation of MHD can be used as a surrogate for mean heart dose in the selection of cases for DIBH.

Pain responses of Pascal 20 ms multi-spot and 100 ms single-spot panretinal photocoagulation: Manchester Pascal Study, MAPASS report 2.

AIMS: To evaluate pain responses following Pascal 20 ms multi-spot and 100 ms single-spot panretinal photocoagulation (PRP). METHODS: Single-centre randomised clinical trial. 40 eyes of 24 patients with treatment-naive proliferative diabetic retinopathy randomised to 20 and 100 ms PRP under topical 0.4% oxybuprocaine. A masked grader used a pain questionnaire within 1 h (numerical pain score (NPS)) and 1 month after treatment (numerical headache score (NHS)). Primary outcome measure was NPS immediately post-PRP. Secondary outcome measures were mean NHS scores and levels of photophobia reported within 4 weeks of primary PRP. RESULTS: Mean laser fluence was significantly lower using 20 ms PRP (4.8 J/cm²) compared to 100 ms PRP (11.8 J/cm²); p < 0.001). Mean NPS scores for treatment were 2.4 (2.3) (mild) for 20 ms PRP group compared to 4.9 (3.3) (moderate) in 100 ms PRP group-a significant difference (95% CI 4.3 to 0.68; p = 0.006). Mean NHS score within 1 month was 1.5 (2.7) in 20 ms PRP group compared to 3.2 (3.5) in the 100 ms PRP group (p < 0.05). The median duration of photophobia after 20 ms PRP was 3 h, and significantly less compared to 100 ms PRP after which 72 h of photophobia was reported (p < 0.001). CONCLUSIONS: Multi-spot 20 ms PRP was associated with significantly lower levels of anxiety, headache, pain and photophobia compared to 100 ms single-spot PRP treatment. Possible reasons include lower fluence, shorter-pulse duration, and spatial summation of laser nociception with multi-spot Pascal technique.

Initial experience with the Pascal photocoagulator: a pilot study of 75 procedures.

BACKGROUND: The Pascal is a semiautomated photocoagulator that delivers a pattern array of multiple burns in a rapid predetermined sequence with a single foot pedal depression. Each burn is reduced to 10 or 20 ms to achieve this. The authors report their early experience with this system. METHODS: 75 procedures done in 60 patients divided into four groups-group A, patients undergoing panretinal photocoagulation (PRP); group B, patients undergoing focal or modified grid macular laser; group C, patients undergoing macular grid and group D, patients undergoing retinopexy-were retrospectively studied. RESULTS: 31/34 procedures in group A, 24/26 procedures in group B, 5/7 procedures in group C and all eight patients in group D had successful outcomes. Significantly higher powers were required with the Pascal than with conventional laser (p<0.001) in eyes that underwent PRP and focal/modified grid macular treatment with both systems. Single session PRP was successfully performed in five patients, and five were successfully treated with a macular grid using pattern arrays only. No adverse events were noted. CONCLUSION: Although the shorter pulse duration of the Pascal necessitates the use of a higher power, it is not associated with adverse effects. The results here suggest that the Pascal photocoagulator is safe and effective, and offer several potential advantages related to the brief exposure time.

Ethnic variation in fluorescein angiography induced nausea and vomiting.

PURPOSE: A prospective survey was undertaken to investigate ethnic variations in the frequency of nausea and vomiting after fundus fluorescein angiography (FFA). METHOD: Between May and September 1998, 197 adult patients were recruited to the study. A questionnaire containing closed-ended questions was completed by nurses after each FFA and a questionnaire was given to patients to complete 5 hours after the procedure at home. Patients' anxiety level was measured before FFA using a 5-item ordinal response scale. RESULTS: Results indicate that patients from black, Asian, Chino-Asian and mixed ethnic origins are significantly more likely to vomit and feel nauseous immediately after the administration of fluorescein dye. Patients with a history of nausea after FFA are significantly more likely to feel nauseous again after repeat FFA. CONCLUSION: Ethnic origin and a previous history of nausea and vomiting appear to be important factors in FFA-induced nausea and vomiting. The results of this study have led the investigators to develop a protocol for the prophylactic treatment of nausea and vomiting following FFA.

Dietary flavonoid and isoflavone glycosides are hydrolysed by the lactase site of lactase phlorizin hydrolase.

Lactase phlorizin hydrolase (LPH; EC 3.2.1.62) is a membrane-bound, family 1 beta-glycosidase found on the brush border of the mammalian small intestine. LPH, purified from sheep small intestine, was capable of hydrolysing a range of flavonol and isoflavone glycosides. The catalytic efficiency (k(cat)/K(m)) for the hydrolysis of quercetin-4'-glucoside, quercetin-3-glucoside, genistein-7-glucoside and daidzein-7-glucoside was 170, 137, 77 and 14 (mM(-1) s(-1)) respectively. The majority of the activity occurred at the lactase and not phlorizin hydrolase site. The ability of LPH to deglycosylate dietary (iso)flavonoid glycosides suggests a possible role for this enzyme in the metabolism of these biologically active compounds.