W. Skinner

The effects of intraurethral lidocaine anesthetic and patient anxiety on pain perception during cystoscopy.

Despite current practice there is no evidence to demonstrate the efficacy of intraurethral lidocaine gel as an anesthetic for rigid cystoscopy. To evaluate the usefulness of lidocaine in decreasing pain associated with cystoscopy, we performed a prospective, randomized, controlled, double-blind study comparing lidocaine gel with a water based lubricant. The effects of pre-procedure anxiety and prior experience with cystoscopy on pain perception were also evaluated. Physician perception of pain experienced by the patient was compared with the actual pain experienced. We found no decrease in pain perception in men or women following lidocaine gel instillation with a 5 or 10-minute dwell time compared to instillation of the plain lubricant. Increased preprocedure anxiety correlated with increased pain perception in women. Personal experience with prior cystoscopic procedures significantly decreased the current pain perception in men. Physicians underestimated the patient pain perception in all groups. Overall, we found the use of lidocaine gel to be of no benefit in routine rigid cystoscopy. Lowering pre-procedure anxiety may decrease the amount of pain perceived by women but not by men.

Hypofractionated whole-breast radiation therapy: does breast size matter?

PURPOSE To evaluate the effects of breast size on dose-volume histogram parameters and clinical toxicity in whole-breast hypofractionated radiation therapy using intensity modulated radiation therapy (IMRT). MATERIALS AND METHODS In this retrospective study, all patients undergoing breast-conserving therapy between 2005 and 2009 were screened, and qualifying consecutive patients were included in 1 of 2 cohorts: large-breasted patients (chest wall separation>25 cm or planning target volume [PTV]>1500 cm3) (n=97) and small-breasted patients (chest wall separation<25 cm and PTV<1500 cm3) (n=32). All patients were treated prone or supine with hypofractionated IMRT to the whole breast (42.4 Gy in 16 fractions) followed by a boost dose (9.6 Gy in 4 fractions). Dosimetric and clinical toxicity data were collected and analyzed using the R statistical package (version 2.12). RESULTS The mean PTV V95 (percentage of volume receiving>=95% of prescribed dose) was 90.18% and the mean V105 percentage of volume receiving>=105% of prescribed dose was 3.55% with no dose greater than 107%. PTV dose was independent of breast size, whereas heart dose and maximum point dose to skin correlated with increasing breast size. Lung dose was markedly decreased in prone compared with supine treatments. Radiation Therapy Oncology Group grade 0, 1, and 2 skin toxicities were noted acutely in 6%, 69%, and 25% of patients, respectively, and at later follow-up (>3 months) in 43%, 57%, and 0% of patients, respectively. Large breast size contributed to increased acute grade 2 toxicity (28% vs 12%, P=.008). CONCLUSIONS Adequate PTV coverage with acceptable hot spots and excellent sparing of organs at risk was achieved by use of IMRT regardless of treatment position and breast size. Although increasing breast size leads to increased heart dose and maximum skin dose, heart dose remained within our institutional constraints and the incidence of overall skin toxicity was comparable to that reported in the literature. Taken together, these data suggest that hypofractionated radiation therapy using IMRT is a viable and appropriate therapeutic modality in large-breasted patients.

Obtaining Normal Tissue Constraints Using Intensity Modulated Radiotherapy (IMRT) in Patients with Oral Cavity, Oropharnygeal, and Laryngeal Carcinoma

The purpose of this study was to evaluate normal tissue dose constraints while maintaining planning target volume (PTV) prescription without reducing PTV margins. Sixteen patients with oral cavity carcinoma (group I), 27 patients with oropharyngeal carcinoma (group II), and 28 patients with laryngeal carcinoma (group III) were reviewed. Parotid constraints were a mean dose to either parotid < 26 Gy (PP1), 50% of either parotid < 30 Gy (PP2), or 20 cc of total parotid < 20 Gy (PP3). Treatment was intensity modulated radiation therapy (IMRT) with simultaneous integrated boost (SIB). All patients met constraints for cord and brain stem. The mandibular constraints were met in 66%, 29%, and 57% of patients with oral, oropharyngeal, and laryngeal cancers, respectively. Mean dose of 26 Gy (PP1) was achieved in 44%, 41%, and 38% of oral, oropharyngeal, and laryngeal patients. PP2 (parotid constraint of 30 Gy to less than 50% of one parotid) was the easiest to achieve (group I, II, and III: 82%, 76%, and 78%, respectively). PP3 (20 cc of total parotid < 20 Gy) was difficult, and was achieved in 25%, 17%, and 35% of oral, oropharyngeal, and laryngeal patients, respectively. Mean parotid dose of 26 Gy was met 40% of the time. However, a combination of constraints allowed for sparing of the parotid based on different criteria and was met in high numbers. This was accomplished without reducing PTV-parotid overlap. What dose constraint best correlates with subjective and objective functional outcomes remains a focus for future study.