Penile bulb dose and impotence after three-dimensional conformal radiotherapy for prostate cancer on RTOG 9406: findings from a prospective, multi-institutional, phase I/II dose-escalation study

PURPOSE: To assess the relationship between the dose to the bulb of the penis and the risk of impotence in men treated on Radiation Therapy Oncology Group (RTOG) 9406. METHODS AND MATERIALS: Men enrolled on a Phase I/II dose-escalation study, RTOG 9406, who were reported to be potent at entry and evaluable (n = 158) were selected for inclusion. Follow-up evaluations were scheduled every 3, 4, and 6 months for the first, second, and the third through fifth years, then annually. At each follow-up visit an assessment of potency status was made. Penile structures were defined by a single observer blinded to the potency status, using Web-based, on-line software. The dosimetry for penile structures was calculated at the Quality Assurance Center at Washington University and provided to RTOG Statistical Headquarters to determine whether there was a relationship between dose and impotence. RESULTS: Patients whose median penile dose was > or = 52.5 Gy had a greater risk of impotence compared with those receiving <52.5 Gy (p = 0.039). In a multivariate analysis neither age, the dose to the prostate, nor the use of hormonal therapy correlated with the risk of impotence. CONCLUSIONS: Dose to the bulb of the penis seems to be associated with the risk of radiation-induced impotence.     

Unusual sites of lymph node metastases and pitfalls in their detection

This pictorial review discusses and illustrates unusual sites of lymph node metastases and their mimics.     

Keeping our feet on the ground: we need to be aware of the dangers of losing focus on patients

Doctors in training are susceptible to thinking themselves more exceptional than reality demonstrates. This tendency, combined with the many pressures of medical training, can lead to a break down in communication with patients. Reminding ourselves of the reality of our role could help us reflect on how we can best benefit them. One important way of doing this is to preserve the aspect of professionalism that health care systems often make difficult--communication.     

Delivering human papillomavirus testing to the public: one patient advocate's perspective

The availability of tests for human papillomavirus (HPV) will lead to increased use of HPV testing as part of cervical cancer screening. To reap the full benefit of HPV testing, that is, benefits both to the women being screened and to the medical system, a systematic public and provider education effort should be undertaken. Key elements of this effort are widely accepted guidelines, clear messages, development of partnerships, and strong leadership from the professional and patient communities. Lessons learned in other public health efforts, such as colorectal cancer screening and human immunodeficiency virus prevention, may be applicable to an HPV education effort.     

Whole-body hyperthermia: a review of theory,design and application

The intentional induction of elevated body temperature to treat malignant lesions has its origins in the 18th century. The mechanism of heat-induced cell death is not clear; however, heat induces a variety of cellular changes. For heat to exert a therapeutic effect, pathogens (bacteria, viruses, or neoplastic tissues) need to be susceptible within temperature ranges that do not exert deleterious effects on normal tissues. Hyperthermia has been used successfully to treat isolated neoplastic lesions of the head and neck, regional tumors such as melanoma of the limb, and is under investigation as either an adjunct to, or therapy for, locally disseminated and systemic diseases. The clinical utility of perfusion hyperthermia has evolved into three approaches - isolated organ or limb, tumorous invasion of a cavity, and systemic or metastatic spread. When whole-body hyperthermic treatment has been tried, it has been induced in the patient by submersion in hot wax or liquid, wrapping in plastic, encasement in a high-flow water perfusion suit, or by extracorporeal perfusion. Our group has developed an extracorporeal method, veno-venous perfusion-induced systemic hyperthermia, that was used first to safely heat swine homogenously to an average body temperature of 43 degrees C for 2 h. More recently, a Phase I clinical trial has been completed in which all patients were safely heated to 42 or 42.5 degrees C for 2 h and survived the 30-day study period. We have been sufficiently encouraged by these results and are continuing to develop this technology.     

Induction of heart rate and blood pressure turbulence in the electrophysiologic laboratory

Heart rate turbulence (HRT) is a transient tachycardia and/or bradycardia that follows ventricular premature complexes (VPCs). Absent or blunted HRT is associated with a poor prognosis in patients with heart disease, but its physiology is unknown. We hypothesized that HRT might be mediated by baroreflexes following early depolarizations. We sought to induce and characterize HRT in the electrophysiologic laboratory by introducing 1 ventricular extrastimulus every 60 seconds in 23 patients who underwent invasive electrophysiologic studies. On average, HRT was characterized by an initial RR interval decrease of 38 ms occurring 3.4 seconds after early depolarization. This was followed by a transient RR interval increase of 88 ms occurring 5.4 seconds later. HRT was preceded by similar hypotensive and/or hypertensive blood pressure turbulence. Baroreflex sensitivity estimates from post-VPCs and sinus sequences were similar (12.3 +/- 10.3 vs 10.2 +/- 8.9 ms/mm Hg, p = 0.51). The failure to induce HRT was associated with a limited initial hypotensive phase of blood pressure turbulence (-7.9 vs -12.1 mm Hg, p = 0.037). Patients with structural heart disease had reduced turbulence onset and reduced turbulence slope relative to those with structurally normal hearts, although blood pressure response was similar in both groups. HRT is an inducible, transient tachycardia and/or bradycardia that likely arises from a baroreflex response to transient hypotension following VPCs. Patients with structural heart disease have blunted HRT.