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Biomedical subjects

Peter A S Johnstone

Publications and source records attributed to Peter A S Johnstone.

At least 19 recordsLinked to original sources
PubMed2007

Neuroblastoma in adults: Incidence and survival analysis based on SEER data.

PURPOSE: Clinical data on survival outcomes of adult patients (defined as 20 years of age and older) with neuroblastoma are scarce due to the rarity of the disease. Small single institution reports have described worse outcomes for adults than pediatric patients. MATERIALS/METHODS: Data from the public access Surveillance Epidemiology and End Results database were reviewed for a 30-year period between 1973 and 2002 for the diagnosis of neuroblastoma. Analyses compared frequency and survival rates of neuroblastoma among children and adults with particular focus on the incidence, case characteristics, and long-term survival of the adult patients. RESULTS: The observed 3- and 5-year survival rates were lowest among adult patients (45.9% and 36.3%, respectively), whereas infants fared best with 86.0% 3-year and 84.6% 5-year overall survival. There was a steady decline in the incidence of adult neuroblastoma from 0.47 cases per million per year in 1973-1977 to 0.12 cases per million per year in 1998-2002. When the long-term adult neuroblastoma survival was examined in detail for 1-, 3-, 5-, 7-, and 10-year follow-up periods, there was continuous decrease in survival during the first 7 years after the diagnosis with subsequent stabilization for both observed (OS) and relative survival (RS) rates. There was a notable trend towards improved outcome over the past three decades. CONCLUSIONS: Adults with neuroblastoma have significantly worse outcome than children. This may be due to tumor biology, more virulent clinical course, or possibly due to the fact that adults are less sensitive or have poor tolerance to pediatric chemotherapy regimens.

Adolescent↗
PubMed2006

Free breathing gated delivery (FBGD) of lung radiation therapy: analysis of factors affecting clinical patient throughput.

PURPOSE: Accurate radiation targeting and delivery within the chest and abdomen is greatly affected by the respiratory cycle. Prior methods to minimize respiratory effect include breath-hold and abdominal compression techniques; these are subject to error secondary to variable inspiration/expiration volumes, or by the nature of many cancer patients having inherently poor respiratory function. However, advanced technology called free breathing gated delivery (FBGD) allows patients to breath normally during treatment. The photon beam is on only during a particular prescribed percentage of the respiratory cycle where the target tumor volume is minimized. Consequently, by using an intermittent beam, the time required to treat a patient is increased. No previous study has described the patient throughput ramifications of FBGD. PATIENTS AND METHODS: At Emory clinic, a gated treatment delivery system was inaugurated into clinical use beginning in June 2004. As of 12/31/2004, 15 patients have completed treatment with FBGD. The majority of patients had lung cancer (n=12) with single cases of adrenal metastasis, thymoma, and atypical carcinoid. Over 900 gated treatment fields (approximately 375 treatment sessions) were reviewed on an IRB-approved retrospective protocol. Records from the record-and-verify (R&V) system were queried using automated database mining software to obtain the treatment room time, treatment field time, beam-on time (BOT), dose rate, and monitor units (MU) for each treatment. The presence or absence of a dynamic wedge was also noted, as was the prescribed percent of the respiratory cycle treated. For comparison purposes, 13 non-gated lung cancer patients (lesions were not moving with respiration) were selected from the R&V database. RESULTS: Patients receiving FBGD required significantly more time for treatment delivery. The time required for FBGD was, on average, 5.5 times greater (range 1.2-12.2) than calculated BOT without gating. Time was further increased with the use of a dynamic wedge, which occurred in 45% (28/62) of the planned fields. The use of MV imaging also increased the time for FBGD treatment sessions by more than 7.5 min on average. CONCLUSIONS: FBGD uniformly increases the time required for RT delivery, and MV imaging and dynamic wedging even more so. Even though this technology more accurately targets tumor volumes while sparing normal tissue, the patient throughput issue may deter this technology from being implemented into busy clinical practices.

Female↗
PubMed2006

Value of PET restaging after chemotherapy for non-Hodgkin's lymphoma: implications for consolidation radiotherapy.

PURPOSE/OBJECTIVE: Patients treated for non-Hodgkin's Lymphoma (NHL) frequently are restaged for response using positron emission tomography (PET) scanning. This study investigates the role of subsequent consolidation radiation therapy (CRT) based on PET response to chemotherapy. MATERIALS/METHODS: An IRB-approved database was queried for patients who underwent PET scans after chemotherapy for NHL between 1995 and 2004; 77 patients were identified. To determine benefit of CRT, overall survival and local control were assessed with median follow-up of 39.8 months (range, 2-125 months). RESULTS: Median age of patients was 53 (range, 18-82 years). Multivariate analysis adjusted for age, indolent vs. aggressive histology, and time from chemotherapy to PET revealed PET positive scans (RR = 30.5; 95%CI = 5.9, 156.4), lack of RT (RR = 5.25; 95%CI = 1.26, 21.79), and Stage III/IV presentation (RR = 4.35; 95%CI = 1.03, 20) predicted increased likelihood of recurrence. Patients with positive PET scans after chemotherapy had significantly higher risk of relapse than those with negative scans (58.1% vs. 15.2%; p < 0.0001), although not everyone with positive scans recurred. Patients with positive PET scans receiving RT were not protected from relapse (63.2% relapse with RT, 50% relapse without RT; p = 0.71); in fact, over half the relapses in patients receiving RT for persistently positive PET scans were in-field. Crude 2 year OS was significantly different between PET positive and PET negative cohorts (p < 0.01). CONCLUSIONS: While RT may control relapse in PET negative patients, NHL patients who remain PET positive after chemotherapy are not well managed by RT alone.

Adolescent↗
PubMed2006

Combined modality therapy for HIV-infected patients with squamous cell carcinoma of the anus: outcomes and toxicities.

PURPOSE: We report toxicity and survival data of human immunodeficiency virus (HIV)-infected men with anal carcinoma treated with combined modality therapy (CMT) of radiotherapy and concurrent chemotherapy. METHODS AND MATERIALS: A retrospective review was performed on the records of 17 HIV-positive patients with anal squamous cell carcinoma treated with CMT at our institution between 1991 and 2004. Radiotherapy consisted of 30.6 to 45 Gy to the pelvis, total dose of 50.4 to 59.4 Gy to initial gross disease, at 1.8 Gy/fraction. Chemotherapy consisted of 5-fluorouracil and either mitomycin C or cisplatin. The mean follow-up was 25.6 months (median, 15.6 months; range, 4.6-106 months). RESULTS: Significant acute skin and hematologic toxicity developed in 8 of 17 and 9 of 17 patients, respectively. One patient died 12 days after treatment of progressive disease and sepsis. Significant late toxic sequelae developed in 3 patients: 1 anorectal ulcer, 2 dermatologic (perianal ulceration, hemorrhagic perineal sores and suspected fissure). Fourteen of 15 patients with Stage I-III disease had a complete response; 2 complete responders subsequently had a relapse in the anorectum. For all patients, actuarial 18-month survival was 67%. For patients with Stage I-III disease, survival at last follow-up by low CD4 count (<200) vs. high count (>200) was 4 of 7 vs. 7 of 8, respectively; significant acute toxicities developed in 4 of 8 vs. 6 of 9, respectively. CONCLUSION: For HIV patients with anal carcinoma, CMT yields reasonable local control with significant acute complications. Survival is lower than in the general population, attributable more to the underlying infection than to the malignancy.

Adult↗
PubMed2006

Radical prostatectomy for clinical T4 prostate cancer.

BACKGROUND: Occasionally, patients with clinical T4 (cT4) prostate cancer undergo surgery. Published data on outcomes after radical prostatectomy (RP) in patients with such advanced stage disease and on the impact of adjuvant radiation therapy (RT) and hormone therapy (HT) are nonexistent. METHODS: Data from the Surveillance Epidemiology and End Results (SEER) data base were reviewed for the 7-year period from 1995 to 2001. Specifically, data were analyzed for 1093 patients with cT4, lymph node-negative or lymph node-positive, M0 prostate cancer without distant lymph node involvement or a history of other cancer. Using follow-up data through 2002, postdiagnosis survival was examined in 5 treatment groups: radical prostatectomy (RP) either alone or in combination with other therapy, radiation therapy (RT) alone, hormone therapy (HT) alone, RT plus HT, and no treatment (NT). All results were expressed as 1-year, 3-year, and 5-year observed survival and corresponding relative survival. Mortality across treatment categories was compared by using a Cox proportionate hazards model controlling for age, year of diagnosis, race, tumor grade, regional lymph node involvement, clinical tumor extension, and SEER registry. RESULTS: Observed and relative survival rates were lowest among patients who received NT and highest among patients who underwent RP. Adding adjuvant RT or HT to RP conferred no survival benefit. Multivariate survival analyses revealed a significant increase in mortality among HT-only patients and among patients who received NT compared with patients who underwent RP. The differences in survival among treatment types were most pronounced in a relatively small group of patients who had positive regional lymph node extension. In all other patients, the results suggested a modest (but not significant) improvement in survival after RT plus HT. CONCLUSIONS: SEER data revealed that patients who underwent RP for cT4 prostate cancer had increased survival compared with patients who received RT alone or HT alone and had a survival comparable to that of patients who received RT plus HT. The benefit of RP appears to be limited to a relatively small subset of patients who have regional lymph node extension.

Aged↗
PubMed2006

Factors influencing long-term survival following salvage total laryngectomy after initial radiotherapy or conservative surgery.

BACKGROUND: This retrospective study investigated survival outcomes of salvage total laryngectomy (STL) after initial radiation therapy (RT) or larynx conservation surgery (CS) at an academic center. METHODS: A chart review yielded 64 patients with STL: 53 with RT failures, six with CS failures, and five after RT + CS. Median potential follow-up after STL was 9.4 years (mean, 9.2 years; range, 0.3-17.4 years). RESULTS: Five- and 10-year actuarial overall survival (OS) after STL was 65.2% and 37.7%, respectively. Mean survival after STL was 7.2 years (median, 6.8 years; range, 0.2-17.4 years). No significant survival difference was found between the three treatment groups (p = .50). For 21 patients with nodes assessed at STL, 9-year OS was 45.4% for patients with N0 disease versus 26.7% for patients with N+ disease (p = .25). CONCLUSION: These data suggest that STL after radiation failure is associated with equivalent long-term survival as STL after RT + CS or after failure of CS alone.

Adult↗
PubMed2006

Can manual treatment of lymphedema promote metastasis?

Complete decongestive therapy (CDT; alternatively known as complete decongestive physiotherapy) is a treatment program for patients diagnosed with primary or secondary lymphedema. CDT incorporates manual lymphatic drainage (MLD), a technique involving therapeutic manipulation of the affected limb. There are several contraindications to performing CDT. Relative contraindications include hypertension, paralysis, diabetes, and bronchial asthma. General contraindications include acute infections of any kind and congestive heart failure. Malignant disease is also widely considered a general contraindication; a current vogue concept is that MLD will lead to dissemination and acceleration of cancer. However, cancer research supports the contention that this therapy does not contribute to spread of disease and should not be withheld from patients with metastasis. The intent of this article is to review these data.

Drainage↗
PubMed2005

Perineural spread of cutaneous malignancy to the brain: a review of the literature and five patients treated with stereotactic radiotherapy.

BACKGROUND: The retrospective analysis was performed to investigate the role of stereotactic radiotherapy (SRT) techniques for patients with intracranial perineural spread (PNS) of a primary cutaneous malignancy. METHODS: Five patients were identified who received SRT from 1993 to 2003 for cutaneous malignancies with intracranial PNS to the cavernous sinus (n = 3) or Meckel's cave (n = 2). Patients were treated with GammaKnife stereotactic radiosurgery (n = 2), linear accelerator (linac)-based fractionated SRT (n = 2), or linac-based stereotactic radiosurgery (n = 1). RESULTS: The median overall survival (OS) periods from diagnoses of cutaneous malignancy and intracranial PNS were 63.0 months (range, 22.0-102.2 months) and 25.5 months (range, 22.0-55.2 months), respectively. The median OS from SRT was 24.2 months (range, 19.5-53.2 months). One patient was alive and without evidence of disease at 53 months of follow-up. The median durations of local and regional control from SRT were 19.5 months (range, 1.5-53.2 months) and 7.0 months (range, 1.5-53.2 months), respectively. CONCLUSIONS: Previous reports generally have recommended that patients with intracranial PNS receive palliative external-beam radiotherapy. Results from the current study suggest that some of these patients may have prolonged survival, or even may be cured. Judicious use of SRT should be considered in their management.

Adult↗
PubMed2005

Postoperative survival and the number of lymph nodes sampled during resection of node-negative non-small cell lung cancer.

STUDY OBJECTIVE: To examine the association between postoperative survival and the number of lymph nodes (LNs) examined during surgery among persons who underwent definitive resection of node-negative (stage IA or stage IB) non-small cell lung cancer (NSCLC). DESIGN AND SETTING: Information on postoperative survival and the number of LNs examined during surgery for stage I NSCLC treated with definitive surgical resection was retrieved from the population-based Surveillance, Epidemiology and End Results database for the period from 1990 to 2000. The association between survival and the number of LNs was examined using multivariate Cox proportional hazard models with adjustment for age, race, sex, type of surgery performed, and tumor size, grade, and histology. RESULTS: A total of 16,800 patients were included in the study. The overall survival analysis for patients without radiation therapy (RT) demonstrated that in comparison to the reference group (one to four LNs), patients with five to eight LNs examined during surgery had a modest but statistically significant increase in survival, with a proportionate hazard ratio (HR) of 0.90 and a 95% confidence interval (CI) of 0.84 to 0.97. Similar results for 9 to 12 LNs and 13 to 16 LNs examined produced further increases in survival, with HRs of 0.86 (95% CI, 0.79 to 0.95) and 0.78 (95% CI, 0.68 to 0.90), respectively. There appeared to be no incremental improvement after evaluating > 16 LNs. The corresponding results for lung cancer-specific mortality and for patients receiving RT were not substantially different. The highest median survival (97 months) occurred in patients with 10 to 11 LNs evaluated. CONCLUSIONS: Our results indicate that patient survival following resection for NSCLC is associated with the number of LNs evaluated during surgery. This is likely due to reduction of staging error: a decreased likelihood of missing positive LNs with an increasing number of LNs sampled. Although we are reluctant to recommend a definitive "optimal number," our data support the conclusion that an evaluation of nodal status should include somewhere from 11 to 16 LNs.

Adult↗
PubMed2005

Management of xerostomia related to radiotherapy for head and neck cancer.

Xerostomia is a permanent and devastating sequela of head and neck irradiation, and its consequences are numerous. Pharmaceutical therapy attempts to preserve or salvage salivary gland function through systemic administration of various protective compounds, most commonly amifostine (Ethyol) or pilocarpine. When these agents are ineffective or the side effects too bothersome, patients often resort to palliative care, for example, with tap water, saline, bicarbonate solutions, mouthwashes, or saliva substitutes. A promising surgical option is the Seikaly-Jha procedure, a method of preserving a single submandibular gland by surgically transferring it to the submental space before radiotherapy. Improved radiation techniques, including intensity-modulated radiotherapy and tomotherapy, allow more selective delivery of radiation to defined targets in the head and neck, preserving normal tissue and the salivary glands. Acupuncture may be another option for patients with xerostomia. All of these therapies need to be further studied to establish the most effective protocol to present to patients before radiotherapy has begun.

Acupuncture Therapy↗
PubMed2004

Survival of patients with untreated rectal cancer.

BACKGROUND AND OBJECTIVES: Untreated rectal cancer is uncommon given modern surgical techniques and chemoradiotherapy. However, neglected cancer may still occur in patients with limited access to medical care or who refuse conventional interventions. Outcome data on such patients is scarce, though valuable in educating patients on their prognosis or to compare with present therapeutic options. METHODS: To identify such data, a review was made of archival literature documenting outcomes in patients with untreated rectal cancer. A review of the Index Medicus and its predecessor volumes and an extensive MEDLINE search led to nine articles that contained relevant age at presentation data of patients with rectal cancer. Six articles also included patient survival data for untreated rectal cancer. Actuarial analysis of the data through 5 years post-diagnosis was completed. RESULTS: Symptoms most often presented in the fifth and sixth decades. Median survival of the 1326 patients fell within the second year after presentation of symptoms. Five-year actuarial survival for these patients was 4.4%. When the data published prior to 1925 were analyzed separately from that published post-1925, two survival patterns emerged. Median survival of pre-1925 patients fell within the second year after presentation of symptoms (at 21.5 months by curve fitting) and of post-1925 patients fell within the first year (10.2 months). CONCLUSIONS: Clearly, advances in antibiotics, surgery, chemoradiotherapy, and supportive care have contributed to increased survival for patients with treated rectal cancer. Recognizing the hazards of generalizing too extremely from the data, they reveal that relatively long survival for patients with untreated lesions is possible.

Actuarial Analysis↗
PubMed2004

Primary retroperitoneal teratomas: a review of the literature.

Teratomas are uncommon neoplasms comprised of mixed dermal elements derived from the three germ cell layers. Historically, teratomas were attributed to demons, sexual misconduct, and abnormal fertilization. They attract attention because of their bizarre histology and gross appearance. While the majority of teratomas present congenitally in the sacrococcygeal region, within the ovaries of adolescent females and within the testes of young men, they have been identified throughout the body. Extragonadal teratomas tend to occur in midline structures as the anterior mediastinum, retroperitoneum, sacrococcygeal region, and pineal gland. Retroperitoneal teratomas represent only 1-11% of primary retroperitoneal tumors. Incidence is bimodal with peaks in the first 6 months of life and in early adulthood. Due to their location, they are usually identified only after they have grown to huge proportions. There is a 25% chance of malignancy. Surgical resection remains the mainstay of therapy and is required for definitive diagnosis. This article reviews the literature on the histopathology, classification, genetic abnormalities, and theories of origin of teratomas as well as the presentation, diagnosis, and management of retroperitoneal teratomas.

Chromosome Aberrations↗
PubMed2003

Radiation tolerance of normal temporal bone structures: implications for gamma knife stereotactic radiosurgery.

Popular current thought states that hearing loss and facial weakness after radiosurgery of vestibular schwannomas is a function of cranial nerve damage. Although this may be true in some cases, the middle and inner ear contain rich networks of other sensitive structures that are at risk after radiotherapy and that may contribute to toxicity afterward. We reviewed the limited reported data regarding radiation tolerance of external, middle, and inner ear structures, and perspectives for therapy with gamma knife stereotactic radiosurgery are addressed.

Dose-Response Relationship, Radiation↗
PubMed2003

Effect of age on biochemical disease-free outcome in patients with T1-T3 prostate cancer treated with definitive radiotherapy in an equal-access health care system: a radiation oncology report of the Department of Defense Center for Prostate Disease Research.

PURPOSE: It has traditionally been a common perception that young age is a negative prognostic factor in prostate cancer (CaP). Furthermore, many urologists believe that younger patients are better suited to surgery rather than radiotherapy (RT) because of this perception. However, the data on the effect of age on outcome in patients with CaP are unclear. The records of the Department of Defense Center for Prostate Disease Research were queried for the biochemical disease-free results of patients after definitive RT and analyzed by age. MATERIALS AND METHODS: The records of 1018 patients with T1-T3 CaP treated with definitive RT between 1988 and 2000 were reviewed. The records of patients receiving adjuvant hormonal therapy or adjuvant or salvage RT postoperatively were excluded. Biochemical failure was calculated by the American Society for Therapeutic Radiology and Oncology criteria. The median potential follow-up was 85.3 months as of December 31, 2001. RESULTS: Age did not affect biochemical disease-free survival significantly when considered as <60 vs. >/=60 years (p = 0.646), by decade (p = 0.329), or as a continuous variable (correlation coefficient r = 0.017, regression slope = 0.007, with p = 0.588 and R(2) < 0.001). Using multiple regression analysis, age was still not significant (p = 0.408). Other variables analyzed were pretreatment prostate-specific antigen level (p < 0.001), Gleason sum (p = 0.023), stage (p = 0.828), and RT dose (p = 0.033). CONCLUSIONS: Age and biochemical disease-free survival after RT for CaP are not related. Age may not be a valid factor in choosing between primary treatment options for CaP.

Adult↗