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Dive into the research topics where Peter A.S. Johnstone is active.

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Featured researches published by Peter A.S. Johnstone.


International Journal of Radiation Oncology Biology Physics | 2001

Acupuncture for pilocarpine-resistant xerostomia following radiotherapy for head and neck malignancies.

Peter A.S. Johnstone; Y.Peter Peng; Byron C. May; Warren S Inouye; Richard C. Niemtzow

OBJECTIVEnXerostomia is a frequent and potentially debilitating toxicity of radiotherapy (XRT) for cancers of the head and neck. This report describes the use of acupuncture as palliation for such patients.nnnMETHODS AND MATERIALSnEighteen patients with xerostomia refractory to pilocarpine therapy after XRT for head and neck malignancy were offered acupuncture as palliation. All patients are without evidence of cancer recurrence at the primary site. Acupuncture was provided to three auricular points and one digital point bilaterally, with electrostimulation used variably. The Xerostomia Inventory (XI) was administered retrospectively to provide an objective measure of efficacy.nnnRESULTSnAcupuncture contributed to relief from xerostomia to varying degrees. Palliative effect as measured by the XI varied from nil to robust (pre- minus post- therapy values of over 20 points). Nine patients had benefit of over 10 points on the XI.nnnCONCLUSIONSnAcupuncture reduces xerostomia in some patients who are otherwise refractory to best current management.


Cancer | 2002

Acupuncture for xerostomia: Clinical update

Peter A.S. Johnstone; M.P.H. Richard C. Niemtzow M.D.; Robert H. Riffenburgh

In the authors clinic, patients with xerostomia after radiation therapy for malignancy have been offered acupuncture as potential palliation of their symptoms since November 1999. Preliminary data revealed that many patients achieve relief, even for symptoms refractory to pilocarpine therapy.


The Journal of Urology | 1998

Second primary malignancies in T1-3N0 prostate cancer patients treated with radiation therapy with 10-year followup

Peter A.S. Johnstone; Curt R. Powell; Robert H. Riffenburgh; David C. Rohde; Christopher J. Kane

PURPOSEnThe risk of patients with prostate cancer to have second primary malignancies is unclear. Population and autopsy based studies have shown no increased risk, which is at variance with several institutional analyses. A retrospective review was performed with comparison to expected cancer data from the Connecticut Tumor Registry.nnnMATERIALS AND METHODSnRecords of a cohort of prostate cancer patients treated with staging pelvic lymphadenectomy and definitive radiotherapy between November 1, 1974 and July 7, 1987 were reviewed. Median potential followup from date of diagnosis was 10.9 years.nnnRESULTSnOf the 164 patients 150 (91.5%) had followup to death or to August 1995, with data available in part on 4 of the remaining patients. In 43 patients 51 second primary malignancies developed. Increased frequency of lymphomas, and kidney, bladder and rectal lesions (all p < 0.001) was observed concurrently with diagnosis of prostate cancer, although this may be due to bias since full staging for the prostate cancer may have led to their diagnosis. An increased frequency of renal lesions in the 1 to 4-year followup period (p = 0.032) also was observed. Two sarcomas and a leukemia were putatively radiation induced but their frequency was not significantly different from the comparison baseline.nnnCONCLUSIONSnMuch of the apparent increase in second primary malignancies associated with prostate cancer noted by some authors may be attributed to bias in the staging process. Renal cancers may occur more frequently in patients with prostate cancer but the distribution of these lesions is inconsistent with a field defect mechanism of cancer induction.


Urologic Oncology-seminars and Original Investigations | 1997

Yield of imaging and scintigraphy assessing biochemical failure in prostate cancer patients.

Peter A.S. Johnstone; Gregory J Tarman; Robert H. Riffenburgh; David C. Rohde; Michael L. Puckett; Christopher J. Kane

A retrospective study was undertaken to determine the diagnostic yield of computed tomography (CT) and bone scan in patients with biochemical failure after definitive therapy for prostate cancer. The records of the Radiation Oncology Division were screened for patients presenting with prostate cancer between January 1, 1993, and December 31, 1996. Of 198 patients, 44 developed biochemical failure postoperatively (n = 24) or postradiotherapy (n = 20), and were not treated with hormones prior to restaging. Review was made of restaging studies performed at the time of biochemical failure. Postoperatively, 5% (1 of 20) of bone scans and 11% (2 of 18) of CT scans were positive. Postradiotherapy, 30% (6 of 20) of bone scans and 30% (3 of 10) of CT scans were positive. Our study showed that imaging studies are of low utility in the evaluation of patients with biochemical failure after definitive therapy of prostate cancer given that most patients begin hormonal therapy irrespective of the results of restaging studies. If salvage therapy is considered, imaging results may have a role in the decision-making process.


The Journal of Urology | 1997

Outcome for Surgically Staged Localized Prostate Cancer Treated With External Beam Radiation Therapy

Curt R. Powell; Thomas K. Huisman; Robert H. Riffenburgh; Eric L. Saunders; Kelly J. Bethel; Peter A.S. Johnstone

PURPOSEnA retrospective analysis was performed on patients with surgically staged localized prostate cancer treated with external beam radiation therapy for 10-year overall, cause specific and disease-free survivals based on lack of clinical recurrence and 2 separate prostate specific antigen criteria for cure.nnnMATERIALS AND METHODSnWe analyzed 145 patients who received external beam radiation therapy after a negative staging pelvic lymphadenectomy for prostate cancer. Followup data were available for 129 patients (90%). Disease was stage A in 29 patients (22.5%), stage B in 64 (49.6%), stage B2/C in 2 (17%) and stage C in 14 (10.9%). Average potential followup from date of diagnosis was 11.5 years (minimum 7.2). Of the patients 87 potentially can be followed for longer than 10 years. Disease-free survival was based on a normal digital rectal examination, lack of symptoms suspicious for metastasis and application of 2 separate prostate specific antigen criteria of 4 ng./ml. or less (group 1), or 1.5 ng./ml. or less (group 2). Survival was analyzed with the Kaplan-Meier actuarial method.nnnRESULTSnActuarial overall survival at 10 and 15 years was 63.7 and 49.6, respectively, and cause specific survival was 84.2 and 80%, respectively. Disease-free survival was 54.5 and 32.4%, respectively, for group 1, and 42.3 and 9.6%, respectively, for group 2.nnnCONCLUSIONSnThe improved patient selection inherent in surgical staging before definitive external beam radiation therapy provides for improved overall and cause specific survival over that of patients without surgical staging. Biochemical disease-free survival also appears to be improved.


International Journal of Radiation Oncology Biology Physics | 2000

Quality of life in T1–3N0 prostate cancer patients treated with radiation therapy with minimum 10-year follow-up

Peter A.S. Johnstone; Christine L. Gray; Curt R. Powell

PURPOSEnTo describe patient-reported quality of life using a validated survey in a cohort of patients who are long-term survivors of definitive radiotherapy for T1-3N0 prostate cancer.nnnMETHODS AND MATERIALSnSurvivors of a previously reported cohort of prostate cancer patients treated with staging pelvic lymphadenectomy and definitive radiotherapy between November 1974 and August 1988 were queried using a questionnaire incorporating the RAND 36-Item Health Survey and the University of California, Los Angeles Prostate Cancer Index. Responses were reviewed and analyzed. Of the 146 N0 patients, 88 have survived for 10 years postdiagnosis. Fifty-six (64%) of these patients were still alive with valid addresses and were mailed copies of the questionnaires, of which 46 (82%) responded. Median potential follow-up from date of diagnosis was 13.9 years, with a median age of responders of 80 years.nnnRESULTSnThe mean sexual function score was 15.4, with a bother score of 42. The mean urinary function score was 65, with a bother score of 61. The mean bowel function score was 72.6, with a bother score of 64.8. The amount of patient bother reported in the sexual category is similar to that previously reported for cohorts of prostate cancer patients undergoing radiotherapy or observation. This is despite the fact that sexual function was similar to that previously reported for patients postprostatectomy. Patient-reported function and bother scores in urinary and bowel categories were somewhat more severe than a previously reported radiotherapy cohort with shorter follow-up.nnnCONCLUSIONSnWith long follow-up, most patients who underwent radiotherapy for prostate cancer in the era described exhibit somewhat worse bladder, bowel, and erectile function than recently published controls without prostate cancer. In this cohort of older men with long follow-up, erectile function is similar to reported prostatectomy series. However, patient bother related to erectile function is similar to that of controls in earlier published radiotherapy series. Worse urinary and bowel function may be due to progressive symptoms with aging and longer follow-up, or to the radiotherapy techniques performed during the era in question.


Urologic Oncology-seminars and Original Investigations | 2000

Glycosaminoglycan content of human bladders ☆ ☆☆: a method of analysis using cold-cup biopsies

Matthew M Poggi; Peter A.S. Johnstone; R.Jeffrey Conner

A glycocalyx layer composed of glycosaminoglycans (GAGs) and other molecules lines the transitional epithelium of the urinary bladder. This layer forms a barrier between the transitional cells and urinary bladder environment and is believed to help prevent the adherence of bacteria, minerals and carcinogens. Investigators postulate that quantitative and/or qualitative defects in the GAG component may be responsible for a spectrum of acute and chronic disease processes ranging from urinary tract infections to cancer. While the presence of epithelium GAGs has been confirmed biochemically and histochemically, few rigorous characterizations have been performed. This study establishes the methodology and feasibility of using routine cold-cup biopsies from cadaveric human bladders for GAG analysis and establishes baseline contents of the sulfated and non-sulfated GAGs in the urinary bladder glycocalyx. Using detergent extraction, the GAGs from cold-cup biopsies (n = 34) from four cadaveric bladders were isolated. The isolates were subjected to two colorimetric assays to quantify both sulfated and non-sulfated GAGs. The nonsulfated GAG content of the bladder epithelium ranged from 2.15 x 10(-4) to 5.50 x 10(-4) mmol/kg of dry, defatted bladder. The sulfated GAG content ranged from 2.00 x 10(-1) to 7.40 x 10(-1) mmol/kg of dry, defatted bladder. These values are consistent with reports found in the literature using electrophoresis on full-thickness human bladder specimens. The GAG content of human bladder epithelium can be readily and accurately characterized from cold-cup biopsy samples. Our future plans involve using this routinely used technique to analyze samples from live control and disease-state bladders thereby demonstrating any quantitative and/or qualitative differences in GAG constituents.


Radiotherapy and Oncology | 2003

Follow-up of head and neck cancer patients post-radiotherapy

William P. O'Meara; Jon K. Thiringer; Peter A.S. Johnstone

Diverging opinions exist regarding follow-up studies post-radiotherapy for head and neck cancer. This report describes the efficacy of follow-up physical examinations, thyroid function tests and screening chest X-rays in post-radiotherapy patients in a practice analysis schema. This analysis suggests that physical examination and thyroid function testing remain valid parts of routine follow-up for head and neck cancer patients; chest X-rays appear less vital unless the patients clinical situation warrants aggressive therapy of a second primary lung cancer.


Journal of Surgical Oncology | 2000

Survival of patients with untreated breast cancer

Peter A.S. Johnstone; Marilyn S. Norton; Robert H. Riffenburgh

Knowing the clinical prognosis of untreated breast cancer is useful in dealing with patients with neglected disease or in environments with poorly developed healthcare systems. This study analyzes historical survival data in two sets of untreated patients: (1) 250 patients followed until death (up to 12 years) for which autopsy results are available and (2) an amalgam of 1,022 patients from several papers. Data from nine published papers underwent actuarial analysis. Median survival time of the 250 patients followed to death was 2.7 years. Actuarial 5‐ and 10‐year survival rates for these patients with untreated breast cancer was 18.4% and 3.6%, respectively. For the amalgamated 1,022 patients, median survival time was 2.3 years. Actuarial 5‐ and (partially fitted) 10‐year survival rates for these patients with untreated breast cancer was 19.8% and 3.7%, respectively. Historical data of untreated breast cancer patients reveal a potential for long survival in some cases. The spectrum of clinical aggressiveness of breast cancer varies between virulence and chronic disease. J. Surg. Oncol. 2000:73:273–277.


The Journal of Urology | 2001

EFFICACY OF DIGITAL RECTAL EXAMINATION AFTER RADIOTHERAPY FOR PROSTATE CANCER

Peter A.S. Johnstone; Joel T. Mcfarland; Robert H. Riffenburgh; Christopher L. Amling

PURPOSEnDigital rectal examination is widely performed for following patients with localized prostate cancer after definitive therapy. This examination has marginal efficacy for detecting initial prostate cancer and postoperative recurrence. To determine the efficacy of digital rectal examination in terms of new information provided after radiotherapy we analyzed the results of digital rectal examination in the followup of patients with prostate cancer after radiotherapy.nnnMATERIALS AND METHODSnWe performed a nonrandomized study in 235 consecutive patients with prostate cancer followed at a large tertiary care military hospital between January 1, 1995 and December 31, 1999. All patients had been treated with prostate radiotherapy and had no evidence of metastatic disease at the first visit within that interval. Digital rectal examination was done at followup and the main outcome measure was new information provided by that examination.nnnRESULTSnA total of 1,544 digital rectal examinations were performed in 1,627 visits. New information was provided by digital rectal examination in only 30% of 286 abnormal examinations, of which more than three-quarters were related to bleeding and would otherwise have been noted on routine examination by the primary care provider. All 8 persistent recurrent prostate nodules were noted in the context of increasing prostate specific antigen.nnnCONCLUSIONSnRoutine digital rectal examination in patients with prostate cancer after radiotherapy may be omitted from followup protocols.

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Robert H. Riffenburgh

Naval Medical Center San Diego

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Curt R. Powell

University of California

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David C. Rohde

University of California

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Byron C. May

Naval Medical Center San Diego

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Christopher L. Amling

Naval Medical Center San Diego

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Marilyn S. Norton

Naval Medical Center San Diego

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Richard C. Niemtzow

Naval Medical Center San Diego

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Tammy E. Mondry

Naval Medical Center San Diego

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