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P Nicholas Plowman

Publications and source records attributed to P Nicholas Plowman.

4 recordsLinked to original sources
PubMed2006

The management of differentiated thyroid cancer using 123I for imaging to assess the need for 131I therapy.

BACKGROUND: Follow-up of 131I whole-body scanning after 131I ablation is associated with potential stunning. Previous studies have suggested that, for scanning, 123I is more sensitive than 131I in identifying thyroid tissue, but its specificity when positive is less certain. AIM: The use of 123I as an imaging agent in place of serial 131I imaging has been evaluated in the surveillance and treatment of differentiated thyroid carcinoma. RESULTS: A total of 186 studies in 136 patients with differentiated thyroid carcinoma were evaluated after total or near total thyroidectomy followed by 131I ablation. In 125 studies 123I scanning was negative and no 131I therapy was given; four patients were positive on 123I scanning but for other reasons no 131I therapy was given. In 48/49 patients a positive 123I scan was followed by positive 131I therapeutic uptake. Only one patient failed to show positive uptake of I when first treated and she subsequently demonstrated uptake on a second therapy. CONCLUSION: High-dose 123I imaging is the correct predictor of the 131I post-therapy scan findings in most cases, at an administered activity that avoids stunning. As a diagnostic agent it is preferable to 131I in differentiated thyroid carcinoma.

Adolescent↗
PubMed2005

Factors influencing cure by transsphenoidal selective adenomectomy in paediatric Cushing's disease.

OBJECTIVE: Early diagnosis and effective treatment of paediatric Cushing's disease (CD) is necessary to minimise associated morbidity. Accepted first-line treatment is selective transsphenoidal microadenomectomy (TSS), which can be technically difficult, and cure rates vary considerably between centres. In our paediatric CD patient group we have assessed the possible factors which may influence cure by TSS. SUBJECTS AND METHODS: From 1983-2004, 27 paediatric patients (16 males, 11 females; mean age+/-s.d., 13.1+/-3.2 yr; range, 6.4-17.8 yr) with CD were managed in our centre and underwent TSS. Sixteen patients (59%), seven males and nine females (mean age+/-s.d., 14.2+/-2.5 yr; range, 8.2-17.8 yr), were cured (post-operative serum cortisol < 50 nM). Eleven patients, nine males and two females (mean age+/-s.d., 11.5+/-3.6 yr; range, 6.4-17.8 yr) had post-operative cortisol levels above 50 nM (2-20 days), with mean serum cortisol levels at 09:00 h of 537 nM (range 269-900 nM) indicating a lack of cure. These 11 patients received external beam pituitary radiotherapy (RT). One patient with a pituitary macroadenoma had a post-operative cortisol level of < 50 nM but 0.8 yr later showed an elevated cortisol and residual disease. RESULTS: The patients cured by TSS alone were significantly older than those not cured (P = 0.038; Student's t test). All patients had CT/MRI pituitary imaging: 14 were reported to have microadenomas and one macroadenoma, while 12 were reported as normal. Bilateral simultaneous inferior petrosal sinus sampling (BSIPSS) with i.v. corticotropin-releasing hormone (CRH) administration was introduced as a pre-operative investigation in 1986 and was performed in 21 patients (78%), on BSIPSS, 16 (76%) had evidence suggesting pituitary adrenocorticotropic hormone (ACTH) secretion (central to peripheral (IPS:P) ACTH ratio after CRH of > or = 3.0) and 16 (76%) showed lateralisation of ACTH secretion (IPSG of > or = 1.4). There was concordance between the BSIPSS finding and the position of the microadenoma at surgery in 17/21 (81%) patients. Of the 16 patients showing lateralisation of ACTH secretion, 12 (75%) were cured by TSS. Of the four without lateralisation of ACTH, suggesting a midline lesion, 3 (75%) were cured by TSS. Post-operative pituitary hormone deficiencies in the patients cured by TSS were: pan-hypopituitarism 1/16, isolated growth hormone deficiency (GHD) (peak GH on glucagon/ITT < 1-17.9 mU/l) 9/16 and diabetes insipidus 3/16. CONCLUSION: Over a 21-year period selective adenomectomy by TSS cured 59% of all paediatric CD patients, with higher age favouring cure. Introduction of BSIPSS resulted in the demonstration of a high rate of lateralisation of ACTH secretion consistent with the surgical identification of the adenoma, and therefore appears likely to have contributed to the higher surgical cure rate.

Adenoma↗
PubMed2003

Clinical and endocrine responses to pituitary radiotherapy in pediatric Cushing's disease: an effective second-line treatment.

Transsphenoidal surgery (TSS) is considered first-line treatment for Cushing's disease (CD). Options for treatment of postoperative persisting hypercortisolemia are pituitary radiotherapy (RT), repeat TSS, or bilateral adrenalectomy. From 1983 to 2001, we treated 18 pediatric patients (age, 6.4-17.8 yr) with CD. All underwent TSS, and 11 were cured (postoperative serum cortisol, <50 nM). Seven (39%) had 0900-h serum cortisol of 269-900 nM during the immediate postoperative period (2-20 d), indicating lack of cure. These patients (6 males and 1 female; mean age, 12.8 yr; range, 6.4-17.8 yr; 4 prepubertal; 3 pubertal) received external beam RT to the pituitary gland, using a 6-MV linear accelerator, with a dose of 45 Gy in 25 fractions over 35 d. Until the RT became effective, hypercortisolemia was controlled with ketoconazole (dose, 200-600 mg/d) (n = 4) and metyrapone (750 mg-3 g/d) +/- aminoglutethimide (1 g/d) or o'p'DDD (mitotane, 3 mg/d) (n = 3). All patients were cured after pituitary RT. The mean interval from RT to cure (mean serum cortisol on 5-point day curve, <150 nM) was 0.94 yr (0.25-2.86 yr). Recovery of pituitary-adrenal function (mean cortisol, 150-300 nM) occurred at mean 1.16 yr (0.40-2.86 yr) post RT. At 2 yr post RT, puberty occurred early in one male patient (age, 9.8 yr) but was normal in the others. GH secretion was assessed at 0.6-2.5 yr post RT in all patients: six had GH deficiency (peak on glucagon/insulin provocation, <1.0-17.9 mU/liter) and received human GH replacement. Follow-up of pituitary function 7.6 and 9.5 yr post RT in two patients showed normal gonadotropin secretion and recovery of GH peak to 29.7 and 19.2 mU/liter. The seven patients were followed for mean 6.9 yr (1.4-12.0 yr), with no evidence of recurrence of CD. In conclusion, pituitary RT is an effective and relatively rapid-onset treatment for pediatric CD after failure of TSS. GH deficiency occurred in 86% patients. Long-term follow-up suggests some recovery of GH secretion and preservation of other anterior pituitary function.

Adolescent↗