Radiation Injury

Outcomes of Early and Late Muscle Flap Salvage of Complicated Lower Extremity Vascular Grafts

Introduction: Muscle flaps are commonly used to protect high-risk vascular grafts in the lower extremities. This study aimed to identify differences between early and late salvage procedures. Methods: Patients undergoing lower extremity vascular reconstruction with muscle flap coverage at a tertiary medical center from 2017 to 2023 were identified. Data included demographics, procedure details, and complications. The study compared early (placed at index or ≤7 d after vascular surgical procedure) versus delayed (>7 d) flap inset. Primary outcomes included rates of infection, hematoma, seroma, necrosis, wound dehiscence, flap failure, and patency of the vascular repair. Secondary outcomes included culture results from the surgical site. Results: Eighty-one patients met inclusion criteria. Early flaps were inset in 53% of cases, and 47% were delayed. Sartorius flaps were most common (53%), followed by gracilis flaps (37%). The indication for flap coverage significantly varied between immediate and delayed flaps (p = 0.004), with immediate more commonly placed for tissue coverage (37%) and delayed inset to address infection (68%). Flap survival (86.1% vs. 76.3%, p = 0.261) and graft patency (74.4% vs. 68.4%, p = 0.55) were similar between groups. Rates of infection, seroma, hematoma, and wound dehiscence did not differ significantly. Regression analysis did not find associated factors with complication incidence. Enterobacter infections were more common in the delayed group (15.8% vs. 2.3%, p = 0.031). Conclusion: This study showed no difference in outcomes between immediate and delayed muscle flaps placed over vascular grafts. Delayed procedures show a greater prevalence of certain bacteria in delayed flaps.

Development of a Novel Clinical Classification for Radiation-induced Cystitis: The Portuguese Navy Radiation-induced Cystitis (PNRC) Scale

Background and objective

Radiation-induced cystitis (RIC) is an important consequence of pelvic radiotherapy that can cause high morbidity and, in extreme cases, mortality. The lack of a widely accepted classification system makes it difficult to compare treatment regimens. Our aim was to develop a new classification system covering the RIC spectrum to improve treatment comparisons and accurate incidence estimates for systematic use in clinical and research settings.

Methods

A three-phase project was planned. Phase 1 involved a literature review and development of the Portuguese Navy Radiation-induced Cystitis (PNRC) scale. In phase 2 the scale was applied to 20 clinical cases. Phase 3 involved assessment of the applicability, relevance, inter-rater reliability, and usability of the scale using numerical and graphical methods to achieve consensus among international experts.

Key findings and limitations

In phase 1, the panel analysed 13 existing classification systems and developed the PNRC scale, a comprehensive system encompassing five clinical domains: haematuria, other lower urinary tract symptoms, functional impairment, endoscopic findings, and therapeutic interventions. In phase 2, 114 experts from 30 countries completed the first validation round. Consensus was reached for 85% of cases. In phase 3, consensus was reached among 61 experts on the relevance and appropriateness of each domain, and on the exhaustiveness, hierarchy, clarity, mutual exclusivity, and clinical utility of the PNRC scale. Study limitations are the inclusion of only Medline-indexed manuscripts in the review and minor dispersion of responses, indicating subjectivity in the analysis of clinical case scenarios.

Conclusions and clinical implications

The PNRC scale showed reliability and face and construct validity in the stratification of RIC severity for clinical cases.

Patient summary

Radiation-induced cystitis is a debilitating complication of pelvic radiotherapy. A uniform classification system is needed to assess the incidence of this disease and to compare the results for different treatment options. We developed the Portuguese Navy Radiation-induced Cystitis (PNRC) scale, which was validated by an independent group of experts from 30 different countries.

Radiation-Induced Pharyngeal Necrosis and Cervical Spine Osteoradionecrosis in Patients With Oropharyngeal Squamous Cell Carcinoma

BACKGROUND

Radiation therapy with or without chemotherapy is commonly used as an adjunct or alternative to surgery for treating head and neck cancer (HNC). In rare cases, radiation-induced side effects such as posterior pharyngeal wall necrosis, fistula formation, and osteoradionecrosis (ORN) can lead to dangerous complications of the cervical spine (C-spine).

METHODS

We conducted a literature review on C-spine ORN in HNC, and we reported four additional cases following the treatment of oropharyngeal carcinoma.

RESULTS

We identified 26 reported cases of C-spine ORN following radiation for HNC. Of the four cases from our institution, two were treated with surgical management and two with conservative measures. Two patients were able to resume oral intake. The median time to diagnosis was 121.5 (range: 22-194) months after completion of radiation.

CONCLUSION

Late complications of radiation can be devastating, severely limiting functional status and quality of life. C-spine ORN is related to total radiation dose and should be discussed with patients as a rare but serious side-effect.

Post radiation mucosal ulcer risk after a hypofractionated stereotactic boost and conventional fractionated radiotherapy for oropharyngeal carcinoma

BACKGROUND/PURPOSE

Post radiation mucosal ulcers (PRMU) after treatment for oropharyngeal squamous cell carcinoma (OPSCC) can have a huge negative impact on patients' quality of life, but little is known concerning risk factors and the impact of fraction size. Therefore, the goal of this study was to determine the pattern of PRMU development and to identify risk factors after a hypofractionated stereotactic body radiotherapy boost (SBRT) compared to conventionally fractionated radiotherapy for OPSCC.

MATERIAL AND METHODS

We performed a retrospective cohort study (N = 332) of OPSCC patients with ≥ 1-year disease-free survival, treated with 46 Gy Intensity Modulated Radiotherapy (IMRT) (2 Gy fractions) followed by either an SBRT boost of 16.5 Gy (5.5 Gy fractions) (N = 180), or 24 Gy IMRT (2 Gy fractions) (N = 152). PRMU (grade ≥ 2) was scored when observed > three months after the last radiotherapy (RT) fraction (CTCAE v5.0). Potential risk factors were analyzed with Cox regression models using death as competing risk. Dose at the PRMU site was calculated by projecting delineated PRMU on the planning CT.

RESULTS

All cases of PRMU (N = 64) occurred within 24 months; all were grade 2. The cumulative incidence at 2 years in the SBRT boost group was 26% (N = 46) vs. 12% (N = 18) for conventional fractionation (p = 0.003). Most PRMU developed within nine months (N = 48). PRMU occurring > nine months (N = 16) were mainly observed in the SBRT boost group (N = 15). Sex (p = 0.048), acute tube feeding (p = < 0.001), tumor subsite tonsil (p = 0.001), and N stage (p = 0.017) were associated with PRMU risk at multivariable regression in the hypofractionated SBRT boost group. All 25 delineated PRMU were located within the high dose regions.

CONCLUSION

The risk of PRMU should be included in the cost benefit analysis when considering future research using a hypofractionated SBRT boost for OPSCC patients.

High-dose irradiation in combination with non-ablative low-dose radiation to treat metastatic disease after progression on immunotherapy: Results of a phase II trial

AIM

To report early findings from a phase II trial of high-dose radiotherapy (HD-RT) with or without low-dose RT (LD-RT) for metastatic cancer.

METHODS

Eligible patients had metastatic disease that progressed on immunotherapy within 6 months. Patients were given either HD-RT (20-70 Gy total; 3-12.5 Gy/f), or HD-RT + LD-RT (0.5-2 Gy/f up to 1-10 Gy total) to separate lesions, with continued immunotherapy. Radiographic response was assessed per RECIST 1.1 and Immune-Related Response Criteria (irRC). Primary endpoints: (1) 4-month disease control (DCR, complete/partial response [CR/PR] or stable disease [SD]) or an overall response (ORR, CR/PR) at any point in ≥10% of patients, per RECIST 1.1; (2) dose-limiting toxicity within 3 months not exceeding 30%. Secondary endpoint was lesion-specific response.

RESULTS

Seventy-four patients (NSCLC, n = 38; melanoma n = 21) were analyzed (39 HD-RT and 35 HD-RT + LD-RT). The median follow-up time was 13.6 months. The primary endpoint was met for 72 evaluable patients, with a 4-month DCR of 42% (47% [16/34] vs. 37% [14/38] in HD-RT + LD-RT vs. HD-RT, P = 0.38), and 19% ORR at any time (26% [9/34] vs. 13% [5/38] in HD-RT + LD-RT vs. HD-RT, P = 0.27). Three patients had toxicity ≥grade 3. LD-RT lesion response (53%) was improved compared to nonirradiated lesions in HD-RT + LD-RT (23%, P = 0.002) and HD-RT (11%, P < 0.001). T- and NK cell infiltration was enhanced in lesions treated with LD-RT.

CONCLUSIONS

HD-RT plus LD-RT safely improved lesion-specific response in patients with immune resistant solid tumors by promoting infiltration of effector immune cells into the tumor microenvironment.

Long and short non-coding RNA and radiation response: a review

Once thought of as arising from "junk DNA," noncoding RNAs (ncRNAs) have emerged as key molecules in cellular processes and response to stress. From diseases such as cancer, coronary artery disease, and diabetes to the effects of ionizing radiation (IR), ncRNAs play important roles in disease progression and as biomarkers of damage. Noncoding RNAs regulate cellular processes by competitively binding DNA, mRNA, proteins, and other ncRNAs. Through these interactions, specific ncRNAs can modulate the radiosensitivity of cells and serve as diagnostic and prognostic biomarkers of radiation damage, whether from incidental exposure in radiotherapy or in accidental exposure scenarios. Analysis of RNA expression after radiation exposure has shown alterations not only in mRNAs, but also in ncRNAs (primarily miRNA, circRNA, and lncRNA), implying an important role in cellular stress response. Due to their abundance and stability in serum and other biofluids, ncRNAs also have great potential as minimally invasive biomarkers with advantages over current biodosimetry methods. Several studies have examined changes in ncRNA expression profiles in response to IR and other forms of oxidative stress. Furthermore, some studies have reported modulation of radiosensitivity by altering expression levels of these ncRNAs. This review discusses the roles of ncRNAs in the radiation response and evaluates prior research on ncRNAs as biomarkers of radiation damage. Future directions and applications of ncRNAs in radiation research are introduced, including the potential for a clinical ncRNA assay for assessing radiation damage and for the therapeutic use of RNA interference (RNAi).

Fascio-cutaneous-free flaps as primary reconstruction in salvage total laryngectomy

INTRODUCTION

Salvage total laryngectomy (STL) is the most common treatment for recurrent laryngeal cancer after (chemo)-radiotherapy [(C)RT]. In this scenario, a higher rate of local wound complications, such as pharyngo-cutaneous fistula (PCF) and pharyngo-esophageal stenosis (PES), is generally expected. The aim of the present study is to evaluate outcomes using a standardized reconstructive protocol.

METHODS

Between 2009 and 2019, patients undergoing STL after (C)RT were collected at two referral hospitals with the objective of evaluating surgical outcomes using a standardized reconstructive policy based on the use of fascio-cutaneous free flaps as inlay patch grafts and a long-lasting salivary bypass stent.

RESULTS

Fifty-five patients (mean age, 66 years; male-to-female ratio, 8:1) were included in the study. Previous treatments were RT in 22 (40%) patients, CRT in 21 (38.2%), and partial laryngeal surgery followed by adjuvant (C)RT in 12 (21.8%). Reconstruction was accomplished by radial forearm and anterolateral thigh free flaps in 16 (29.1%) and 39 (70.9%) patients, respectively. Flap success rate was 98.2%. Concerning postoperative complications, we encountered 3 PCFs (5.4%) and 1 PES (1.8%).

CONCLUSION

The standardized reconstructive protocol analyzed herein granted significantly lower rates of PCF and PES after STL compared with data available in the literature.

Therapeutic Effects of Human Adipose-Derived Products on Impaired Wound Healing in Irradiated Tissue

BACKGROUND

Clinical sequelae of irradiation result in tissue devitalization (e.g., ischemia, fibrosis, and atrophy) where wound healing capacity is impaired. Fat-derived products may work to treat such pathology.

METHODS

Nonlethal irradiation at various doses (5, 10, and 15 Gy) and frequencies (one to three times on sequential days) was delivered to dorsal skin of nude mice, and subsequent gross and microscopic changes were evaluated for up to 4 weeks. Cutaneous punch wounds were then created to compare wound healing in irradiated and nonirradiated states. Wounds were also locally injected with vehicle, cultured adipose-derived stem cells, centrifuged fat tissue, or micronized cellular adipose matrix, and the therapeutic impact was monitored for up to 15 days.

RESULTS

Nude mice given total doses greater than 15 Gy spontaneously developed skin ulcers, and radiation damage was dose-dependent; however, a fractionated irradiation protocol was able to reduce the damage. Histologic assessment revealed dose-dependent dermal fibrosis/thickening and subcutaneous atrophy. Dose-dependent (5 to 15 Gy) impairment of wound healing was also evident. At the highest dosage (15 Gy three times), open wounds persisted on day 15. However, wounds injected with cultured adipose-derived stem cells were nearly healed on day 12, and those treated with injection of centrifuged fat or micronized tissue healed faster than untreated controls (p < 0.05). There was no significant differences between treated groups.

CONCLUSIONS

Tissue devitalization by irradiation was dose-dependent, although fractionated protocols helped to reduce it. Adipose-derived stem cells and other fat-derived products harboring adipose-derived stem cells successfully revitalized irradiated tissues and accelerated wound healing.

Head and Neck Cancer Soft Tissue Radiation Necrosis-Diagnostic Challenge

A 53-year-old man with T4aN2cM0 tongue base squamous cell carcinoma received definitive chemoradiation. FDG PET/CT at 6 weeks showed partial metabolic response with soft tissue air indicating radiation necrosis at primary site and complete response in the neck. At 9 weeks, contrasted CT showed worsening but nonenhancing ulceration, area biopsied demonstrating a minute carcinoma focus with treatment effect. At 12 weeks, PET/CT showed increased primary site uptake interpreted as disease progression; however, no viable tumor was found at salvage surgery. Because nonenhancing ulceration predicts pure radiation necrosis with no viable tumor, contrasted CT may guide treatment selection in challenging cases.

Mount Sinai Medical Center and Their Experience with Unfavorable Microsurgical Head and Neck Reconstruction

Radiation effects on tissues greatly complicate reconstruction of head and neck defects. We discuss the unfavorable surgical conditions set up by prior surgery and radiation in patients undergoing salvage ablation of recurrent cancer. With the focus on vessel selection, flap donor site characteristics, and management of potential complications, we hope to highlight some of the lessons learned from these complex cases. Special attention is given to the topic of laryngopharyngeal reconstruction.

Nipple Reconstruction with the Biodesign Nipple Reconstruction Cylinder: A Prospective Clinical Study

Supplemental Digital Content is available in the text.

Background:

Nipple reconstruction is the last stage in cosmetic reconstruction of the breast after mastectomy, but no method produces reliable and consistent aesthetic results. This study examined the use of the Biodesign Nipple Reconstruction Cylinder (NRC) during reconstruction of the nipple after mastectomy.

Methods:

Patients with a history of breast cancer and mastectomy desiring nipple reconstruction were invited to participate. After obtaining consent, unilateral or bilateral nipple reconstruction was performed. Skin flaps were raised, the NRC was placed beneath the flaps as a stent, and the site was protected for up to 4 weeks with a nipple shield. Nipple projection was measured for 12 months after surgery. Patient satisfaction was measured and adverse events were recorded. Follow-up examinations were performed at 1 week, and then at 1, 3, 6, and 12 months after surgery.

Results:

Eighty-two nipple reconstructions were performed in 50 patients. Related postoperative adverse events were minor, but reported in 8 reconstructions (9.8%) representing 7 patients (14.0%). Average projection at 6 and 12 months was 4.1 ± 1.6 mm and 3.8 ± 1.5 mm, respectively, compared with 10.5 ± 2.2 mm 1 week after surgery. Of patients completing the satisfaction questionnaire at 12 months, 70/75 (93.3%) of reconstructions were rated “pleased” or “very pleased” with the overall outcome. Overall, 45/46 (97.8%) patients would recommend nipple reconstruction to other women.

Conclusions:

The Biodesign NRC offers a safe alternative to nipple reconstruction, resulting in stable projection and a high level of patient satisfaction for 12 months after placement.

A Meta-analysis of Outcomes Using Acellular Dermal Matrix in Breast and Abdominal Wall Reconstructions: Event Rates and Risk Factors Predictive of Complications

BACKGROUND

The use of acellular dermal matrix (ADM) has gained acceptance in breast and abdominal wall reconstructions. Despite its extensive use, there is currently a wide variation of reported outcomes in the literature. This study definitively elucidates the outcome rates associated with ADM use in breast and abdominal wall surgeries and identifies risk factors predisposing to the development of complications.

METHODS

A literature search was conducted using the Medline database (PubMed, US National Library of Medicine) and the Cochrane Library. A total of 464 articles were identified, of which 53 were eligible for meta-analysis. The endpoints of interest were the incidences of seroma, cellulitis, infection, wound dehiscence, implant failure, and hernia. The effects of various risk factors such as smoking, radiation, chemotherapy, and diabetes on the development of complications were also evaluated.

RESULTS

A majority of the studies were retrospective (68.6%) with a mean follow-up of 16.8 months (SD ± 10.1 months) in the breast group and 14.2 months (SD ± 7.8 months) in the abdominal wall reconstructive group. The overall risks and complications were as follows: cellulitis, 5.1%; implant failure, 5.9%; seroma formation, 8%; wound dehiscence, 8.1%; wound infection, 16.1%; hernia, 27.6%; and abdominal bulging, 28.1%. Complication rates were further stratified separately for the breast and abdominal cohorts, and the data were reported. This provides additional information on the associated abdominal wall morbidity in patients undergoing autologous breast reconstruction in which mesh reinforcement was considered as closure of the abdominal wall donor site. Radiation resulted in a significant increase in the rates of cellulitis (P = 0.021), and chemotherapy was associated with a higher incidence of seroma (P = 0.014).

CONCLUSION

This study evaluates the overall complication rates associated with ADM use by conducting a meta-analysis of published data. This will offer physicians a single comprehensive source of information during informed consent discussions as well as an awareness of the risk factors predictive of complications.

Ghost Protocol: Greatest Healing Opportunity for Soft Tissue, a Treatment Paradigm for Complex Sarcoma Reconstruction

Modern sarcoma treatment has created new challenges for plastic surgeons. This study was designed to review the recent experience and practice patterns following complex sarcoma resection at a large sarcoma center. All cases from October 2013 to October 2014 involving rare nonepithelial tumors, a multidisciplinary surgical team, radiation and/or chemotherapy treatments, and plastic surgical reconstruction were included in the analysis. In addition to evaluating clinical outcomes, cases were reviewed to identify factors associated with excellent or poor patient care. Review of these cases formed the basis of the greatest healing opportunity for soft tissue (GHOST) protocol. Our patient population included seven males (64%) and four females (36%). All except one patient was exposed to radiotherapy, chemotherapy, or some combination. Diverse procedures were used for reconstruction. Early complications occurred in two patients (18%), and late complications in four patients (36%). Sarcoma resection was found to be highly morbid in our series. Patients with poor preoperative nutritional status were more likely to experience complications postoperatively. The decision to stage a reconstruction was complex and influenced by several factors. Multimodal sarcoma treatments may involve highly morbid procedures and create complex wounds. The GHOST protocol is a useful reference for plastic surgeons.

Allograft AlloDerm(®) tissue for laparoscopic transabdominal preperitoneal groin hernia repair: A case report

INTRODUCTION

Synthetic mesh is the prosthetic material used for most inguinal hernioplasties. However, when left in contact with intra-abdominal viscera, it often becomes associated with infection and migration, particularly in irradiated tissues, contaminated fields, immunosuppressed individuals, and patients with intestinal obstruction or fistula. AlloDerm^® Regenerative Tissue Matrix (LifeCell Corporation, Branchburg, NJ) is derived from human cadaver skin and may be associated with fewer visceral adhesions and more durability in infected fields than synthetic mesh.

PRESENTATION OF CASE

We report the first case in which AlloDerm was used in a laparoscopic transabdominal preperitoneal repair of a multiple recurrent right inguinal hernia, a left femoral hernia, and an umbilical hernia in the same patient. Use of AlloDerm greatly enhanced the maneuverability during laparoscopic hernia repair due to its pliability and strength and eliminated the need to cover the prosthetic with peritoneum.

DISCUSSION

Previous pelvic radiation and multiple previous groin repairs can render the peritoneum friable, resulting in obstacles to successful closure. AlloDerm is a reasonable choice for groin hernia repairs when such factors are present.

CONCLUSION

The long-term durability of AlloDerm for laparoscopic groin hernia repairs is yet to be determined, but based on current data it seems prudent to use this technique in laparoscopic repair of complex groin hernias where infection is suspected or inadequate prosthetic coverage with peritoneum is anticipated.

Primary fascial closure with mesh reinforcement is superior to bridged mesh repair for abdominal wall reconstruction

BACKGROUND

Many surgeons believe that primary fascial closure with mesh reinforcement should be the goal of abdominal wall reconstruction (AWR), yet others have reported acceptable outcomes when mesh is used to bridge the fascial edges. It has not been clearly shown how the outcomes for these techniques differ. We hypothesized that bridged repairs result in higher hernia recurrence rates than mesh-reinforced repairs that achieve fascial coaptation.

STUDY DESIGN

We retrospectively reviewed prospectively collected data from consecutive patients with 1 year or more of follow-up, who underwent midline AWR between 2000 and 2011 at a single center. We compared surgical outcomes between patients with bridged and mesh-reinforced fascial repairs. The primary outcomes measure was hernia recurrence. Multivariate logistic regression analysis was used to identify factors predictive of or protective for complications.

RESULTS

We included 222 patients (195 mesh-reinforced and 27 bridged repairs) with a mean follow-up of 31.1 ± 14.2 months. The bridged repairs were associated with a significantly higher risk of hernia recurrence (56% vs 8%; hazard ratio [HR] 9.5; p < 0.001) and a higher overall complication rate (74% vs 32%; odds ratio [OR] 3.9; p < 0.001). The interval to recurrence was more than 9 times shorter in the bridged group (HR 9.5; p < 0.001). Multivariate Cox proportional hazard regression analysis identified bridged repair and defect width > 15 cm to be independent predictors of hernia recurrence (HR 7.3; p < 0.001 and HR 2.5; p = 0.028, respectively).

CONCLUSIONS

Mesh-reinforced AWRs with primary fascial coaptation resulted in fewer hernia recurrences and fewer overall complications than bridged repairs. Surgeons should make every effort to achieve primary fascial coaptation to reduce complications.

Complex reconstruction of desmoid tumor resections does not increase desmoid tumor recurrence

BACKGROUND

The propensity of desmoid tumors to develop in scars has led some surgeons to limit the complexity of desmoid defect reconstruction as a strategy for avoiding desmoid recurrence. We hypothesized that desmoid recurrence rates are similar despite the magnitude of reconstruction.

STUDY DESIGN

We retrospectively compared recurrence rates between patients who underwent reconstruction and patients who underwent primary closure without reconstruction after desmoid tumor resection in consecutive patients for 15 years. Univariate and multivariate regression analyzed associations between patient, tumor, and treatment characteristics and outcomes.

RESULTS

We included 164 consecutive patients (80 [49%] reconstructions vs 84 [51%] primary closures). Mean follow-up duration was 7.1 ± 4.5 years. Patients who underwent reconstruction had more desmoids in an area of earlier trauma or surgery (p < 0.001), greater defect volume (p < 0.01), longer operative time (p < 0.001) and hospital stay (p < 0.001), and more postoperative complications (p = 0.015) compared with the primary closure group. Despite these differences, desmoid recurrence rates were similar for the reconstruction and primary closure groups (30% and 29%, respectively; p = 0.7), as was mean time to tumor recurrence, and no tumors recurred within flap donor sites. Multivariate regression analysis demonstrated the 45F mutation to be the only independent predictor of recurrence (hazard ratio = 1.87; p = 0.04).

CONCLUSIONS

Rates of desmoid recurrence in resection defects are similar for primary closures and complex reconstructions. Therefore, surgeons should not limit the magnitude of reconstructions in an attempt to avoid tumor recurrence. However, given the propensity of desmoids to recur, reconstructions should allow for the possibility of future resections and reconstructions, particularly in tumors with 45F gene mutations.

Wound healing after radiation therapy: review of the literature

Radiation therapy is an established modality in the treatment of head and neck cancer patients. Compromised wound healing in irradiated tissues is a common and challenging clinical problem. The pathophysiology and underlying cellular mechanisms including the complex interaction of cytokines and growth factors are still not understood completely. In this review, the current state of research regarding the pathomechanisms of compromised wound healing in irradiated tissues is presented. Current and possible future treatment strategies are critically reviewed.

Imaging of the Head and Neck following Radiation Treatment

Squamous cell carcinoma of the head and neck occurs in approximately 40,000 patients annually in the United States and is often treated with radiation therapy. Radiological studies are obtained following treatment for head and neck malignancies to assess for recurrent tumor, posttreatment changes, and associated complications. Radiation treatment creates a difficult clinical picture for oncologists, head and neck surgeons, neuroradiologists, and neuropathologists. As post-treatment imaging studies are often discussed at radiology/pathology working conferences, knowledge of the imaging appearance of radiation-associated changes in the head and neck and the terminology used by neuroradiologists may not only aid in interpretation of the pathologic specimen, but also assist in communications with neuroradiologists and referring clinicians.

New method of tunnelling for omental transposition in the treatment of a complex radionecrotic groin ulcer

Omental transposition is often used for reconstruction of soft tissue in the groin. However, the potential for incisional hernia is a relative contraindication. We report the cure of a groin ulcer with omental transposition using a new method of tunnelling to avoid herniation.

Surveillance, control, and prevention of surgical site infections in breast cancer surgery: a 5-year experience

BACKGROUND

We analyzed variations in surgical site infections (SSIs) during 5 years of a prospective surveillance program and investigated possible contributors to SSIs in a cohort of patients who underwent surgery for breast cancer.

METHODS

All breast surgeries performed between January 2001 and December 2005 were registered. Patients were followed-up by direct observation for at least 30 days under standardized conditions. The main outcome studied was SSI. A case-control analysis was conducted to identify SSI-associated risk factors and to evaluate SSI variations by means of a control chart.

RESULTS

During the study period, a total of 2338 breast cancer surgeries were recorded, and 441 SSIs (18.9%) were diagnosed. SSI frequency varied across the 5-year period, with a sharp decline seen after the introduction of preventive policies. After 2002, 3 out-of-confidence limits of SSIs were observed, 2 related to the use of evacuation systems and 1 associated with a group of rotating residents. Concomitant preoperative chemoradiation (odds ratio [OR]=3.47; 95% confidence interval [CI]=2.51 to 4.80), hematoma (OR=3.05; 95% CI=1.70 to 5.52), age > or = 58 years (OR=1.83; 95% CI=1.27 to 2.65), body mass index > or = 30.8 (OR=1.58; 95% CI=1.14 to 2.18), and duration of surgery > or = 160 minutes (OR=1.73; 95% CI=1.20 to 2.50) were found to be SSI-associated risk factors.

CONCLUSIONS

After 5 years of a continuous prospective surveillance program, we were able to decrease the rate of SSIs in patients undergoing breast cancer surgery (from 33.3% in 2000 to 18.9% in 2005), identify SSI-associated risk factors, and improve the quality of care delivered to these patients.

Development of an intramuscular xenograft model of canine osteosarcoma in mice for evaluation of the effects of radiation therapy

OBJECTIVE

To develop an IM xenograft model of canine osteosarcoma in mice for the purpose of evaluating effects of radiation therapy on tumors.

ANIMALS

27 athymic nude mice.

PROCEDURES

Mice were randomly assigned to 1 of 3 groups of 9 mice each: no treatment (control group), radiation at 10 Gy, or radiation at 15 Gy. Each mouse received 5 x 10(5) highly metastasizing parent osteosarcoma cells injected into the left gastrocnemius muscle. Maximum tumor diameter was determined with a metric circles template to generate a tumor growth curve. Conscious mice were restrained in customized plastic jigs allowing local tumor irradiation. The behavior and development of the tumor xenograft were assessed via evaluations of the interval required for tumor-bearing limbs to reach diameters of 8 and 13 mm, extent of tumor vasculature, histomorphology of tumors, degree of tumor necrosis, and existence of pulmonary metastasis and clinical disease in affected mice.

RESULTS

Tumor-bearing limbs grew to a diameter of 8 mm (0.2-g tumor mass) in a mean +/- SEM interval of 7.0 +/- 0.2 days in all mice. Interval to grow from 8 to 13 mm was significantly prolonged for both radiation therapy groups, compared with that of the control group. Histologic evaluation revealed the induced tumors were highly vascular and had characteristics consistent with those of osteosarcoma. Pulmonary metastasis was not detected, and there was no significant difference in percentage of tumor necrosis between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

A reliable, repeatable, and easily produced IM xenograft model was developed for in vivo assessment of canine osteosarcoma.

Cytokine treatment improves parenchymal and vascular damage of salivary glands after irradiation

PURPOSE

During radiotherapy for head and neck cancer, co-irradiation (IR) of salivary glands results in acute and often lifelong hyposalivation. Recently, we showed that bone marrow-derived cells (BMC) can partially facilitate postradiation regeneration of the mouse submandibular gland. In this study, we investigate whether optimized mobilization of BMCs can further facilitate regeneration of radiation-damaged salivary glands.

EXPERIMENTAL DESIGN

Salivary glands of mice reconstituted with eGFP+ bone marrow cells were irradiated with a single dose of 15 Gy. One month later, BMCs were mobilized using granulocyte colony-stimulating factor (G-CSF) or the combination of FMS-like tyrosine kinase-3 ligand, stem cell factor, and G-CSF (termed F/S/G) as mobilizing agents. Salivary gland function and morphology were evaluated at 90 days post-IR by measuring the saliva flow rate, the number of acinar cells, and the functionality of the vasculature.

RESULTS

Compared with G-CSF alone, the combined F/S/G treatment mobilized a 10-fold higher number and different types of BMCs to the bloodstream and increased the number of eGFP+ cells in the irradiated submandibular gland from 49% to 65%. Both treatments reduced radiation-induced hyposalivation from almost nothing in the untreated group to approximately 20% of normal amount. Surprisingly, however, F/S/G treatment resulted in significant less damage to submandibular blood vessels and induced BMC-derived neovascularization.

CONCLUSIONS

Post-IR F/S/G treatment facilitates regeneration of the submandibular gland and ameliorates vascular damage. The latter is partly due to BMCs differentiating in vascular cells but is likely to also result from direct stimulation of existing blood vessel cells.

Pocket work for optimising outcomes in prosthetic breast reconstruction

Implant breast reconstruction is a recommendable alternative for women who have undergone mastectomy and lack the necessary subcutaneous fat tissue for an autologous reconstruction. On the other hand, many women reject the morbidity of the donor site, prolonged recovery periods and muscular weakness associated with autologous reconstruction. Therefore, muscle and skin expansion has become one of the most popular approaches used in breast reconstruction. Nevertheless, the expansion process may be hindered by events like seroma formation, implant rotation, moving upward or downward altering the location or shape of the submammary crease, capsule contracture or extrusion. Since the advent of the anatomical expander, two-stage reconstruction with the expander/implant sequence has become the most popular choice in prosthetic breast reconstruction (PBR). The second surgical stage, in which the tissue expander is exchanged for the permanent implant, offers a unique opportunity for pocket work. Pocket work strategies and their indications should be known and applied by the surgeon who aims at optimising PBR aesthetic results.

Benign ulceration as a manifestation of soft tissue radiation necrosis: imaging findings

BACKGROUND AND PURPOSE

The purpose of this study was to review CT imaging findings of soft tissue mucosal ulceration in patients following radiation treatment for head and neck malignancies and to correlate these with patient outcomes.

MATERIALS AND METHODS

The CT examinations in 20 patients with soft tissue ulceration after radiation therapy for treatment of head and neck cancer were reviewed. External beam radiation therapy was completed between 3 and 61 months (mean, 11.5 months) before the initial diagnosis of soft tissue ulceration. In all 20 patients, the initial diagnosis was made or confirmed on CT examination.

RESULTS

Of the 20 ulcerations, 12 did not demonstrate enhancement, and the results of biopsy in 9 of these 12 were negative. Of the 12 nonenhancing ulcerations, biopsy was not performed in 3, but they have been followed clinically and radiologically for 15.7 months without evidence of recurrence. Of the 20 ulcerations, 8 demonstrated adjacent enhancement, and the results of a biopsy in 4 were positive for recurrent cancer and negative in 2; these 2 have been followed for 16.3 months without evidence of recurrence. Biopsy was not performed in 2 ulcerations, but they have been followed for 15.0 months without evidence of recurrence.

CONCLUSION

For soft tissue ulceration occurring after radiation treatment, if there is no enhancement or clinical evidence of recurrence, it is likely benign and follow-up without biopsy seems warranted. If the ulceration is associated with adjacent enhancement, then differentiation between radiation necrosis and recurrent tumor is difficult. In these cases, correlation with clinical examination with close interval follow-up is necessary if a biopsy is not performed.

Radiotherapy and wound healing

This review article discusses basic radiation physics and effects of radiation on wounds. It examines various postulated hypothesis on the role of circulatory decrease and radiation-induced direct cellular damage. The new concept related to the radiation pathogenesis proposes that there is a cascade of cytokines initiated immediately after the radiation. Sustained activation of myofibroblasts in the wound accounts for its chronicity. Recent advances highlight that transforming growth factor beta1 is the master switch in pathogenesis of radiation fibrosis. This articles overviews its role and summarises the available evidences related to radiation damage. The goal of this article was to provide its modern understanding, as future research will concentrate on antagonising the effects of cytokines to promote wound healing.

The effect of head-fractioned teletherapy on pulp tissue

AIM

To evaluate the early and delayed effects of fractioned teletherapy (radiotherapy) on the dental pulps of rats using Co(60).

METHODOLOGY

In group 1 - rats (n = 15) were subjected to fractioned teletherapy by 30 daily sessions fractioned in doses of 200 cGy day(-1), totaling 60 Gy and the rats were killed immediately after the final dose of irradiation; group 2 - same protocol but killed 30 days following the final irradiation dose; groups 3 (n = 7) and 4 (n = 8) - formed controls without irradiation. Following perfusion, the left mandible of each rat was dissected and processed for histopathology. Serial sections (5 microm) were obtained and stained with HE or picrosirius. Observations were recorded for the coronal pulp tissue. A blinded observer evaluated HE sections using pre-defined indices of inflammation, nuclear alterations and extracellular matrix (ECM) hyalinization. Images of sections stained with picrosirius were converted to black and white for analysis by image-pro plus; areas in black (collagen) were measured as percentage area. The pulps of mandibular incisors of the specimens prepared for transmission electron microscopy (TEM) were subjected to descriptive analysis. Magnifications of 6300 and 10000 x were used to observe 10 pulp fibroblasts from each group.

RESULTS

No inflammatory reactions or modification of the ECM status were found (P = 0.428) in any specimens. The collagen content also displayed no significant changes (P = 0.067) as a result of treatment. Groups 1 and 2 displayed significantly more nuclear alterations than the control groups (P < 0.05). The bubble-like aspect was more pronounced in group 1, and the bubbles looked smaller in group 2. The ECM showed no differences in the hyalinization status and there were no differences in the collagen area within the pulps. Under TEM, the pulp fibroblasts in group 1 displayed nuclear alterations that resembled circular, oval or elongated perforations; perforations also appeared in the cytoplasm.

CONCLUSION

Fractioned teletherapy is capable of producing nuclear alterations in the dental pulp tissue of rats.

Radiation responses in skin and connective tissues: effect on wound healing and surgical outcome

Radiation therapy, either alone or in combination with other types of treatment, is responsible for 40% of cancer cures and 70% of all cancer patients receive radiation therapy at some point during the course of their disease. Radiation therapy has profound effects, both acute and long-term, on skin and connective tissues. Radiation therapy also affects the time course and end result of wound healing, and the risk of postoperative complications. For example, radiation therapy of tumors in the abdomen or in the abdominal wall inevitably affects the integrity of abdominal wall structures and may adversely affect the outcome of operations on the abdominal wall, for example hernia surgery. All surgeons will encounter patients who have undergone or will receive radiation therapy. In these situations, it is important to carefully consider the optimum timing of surgery relative to radiation therapy, to decide which perioperative precautions are needed to minimize the risk of complications, to estimate and inform the patient about the increased risk of complications, and, if surgery is done before a planned course of radiation therapy, to consider how soon after surgery it is safe to commence the radiation treatment. This review will (1) describe features of acute and long term radiation-induced changes in skin and connective tissues; (2) provide a brief overview of the biological mechanisms underlying these changes; and (3) discuss practical considerations that have direct relevance to surgical decision making and postoperative outcome.

Análise microscópica do efeito da radioterapia fracionada por cobalto-60 em mandíbula de rato

OBJETIVO: O objetivo deste estudo foi avaliar o efeito imediato e tardio da teleterapia fracionada por cobalto-60 sobre o percentual médio de osteoplastos em mandíbula de ratos. MATERIAIS E MÉTODOS: Os animais (n = 45) foram divididos em três grupos: grupo 1 (n = 15) - submetidos a teleterapia fracionada e sacrificados terminada a última dose de irradiação; grupo 2 - idêntico ao grupo 1, porém mortos 30 dias após a conclusão da teleterapia; grupo 3 (n = 15) - não-irradiado, servindo como grupo-controle. O protocolo radioterápico consistiu de 30 sessões de teleterapia, fracionadas em doses de 2 Gy/dia, totalizando 60 Gy. Após a perfusão dos animais com paraformaldeído a 4%, a hemimandíbula esquerda foi processada histologicamente. Secções seriadas (5 µm) foram coradas com hematoxilina-eosina. Selecionaram-se duas áreas próximas às raízes dos primeiros e segundos molares. O percentual médio de osteoplastos foi calculado nessa região, em duplicata, valendo-se do programa Image Tool. RESULTADOS: A análise de variância, complementada pelo teste de comparações múltiplas de Tukey, evidenciou que os grupos irradiados 1 e 2 não diferiram entre si, apresentando maiores percentuais de osteoplastos (p = 0,005) quando comparados com o grupo-controle. CONCLUSÃO: Concluiu-se que a teleterapia fracionada por cobalto-60, na dose estabelecida, provoca um aumento do número de osteoplastos em tecido ósseo mandibular de ratos.

The protective effect of interleukin-11 on the cell death induced by X-ray irradiation in cultured intestinal epithelial cell

Interleukin-11 (IL-11) is a well known anti-inflammatory cytokine that is associated with cell growth, and also participates in limiting X-ray irradiation induced intestinal mucosal injury. The aim of this study was to evaluate the protective effect of IL-11 on the cell injury induced by X-ray irradiation in rat intestinal epithelial IEC-18 cells. Recombinant human IL-11 (rhIL-11) treated cells were irradiated and then examined for cell viability. To evaluate irradiation injury, trypan blue staining was used to detect the dead cells. The viability of irradiated cells was up-regulated by rhIL-11 treatment and also resulted in the activation of p90 ribosomal S6 kinase (p90RSK) and S6 ribosomal protein (S6Rp). Wortmannin, a specific inhibitor of PI3K, suppressed the activation of S6Rp in rhIL-11 treated cells, and decreased the up-regulation of viability by rhIL-11 treatment in irradiated cells. The TUNEL assay was also perfomed to estimate the rate of apoptosis in X-ray induced cell death. There was no difference in the results between trypan blue staining and the TUNEL assay. Further, rhIL-11 down-regulated the expression of cleaved caspase-3 in irradiated cells. These results suggest that rhIL-11 may play an important role in protection from radiation injury.

Improving the morbidity of anorectal injury from pelvic radiotherapy

OBJECTIVE

Radiation anorectal injury due to pelvic radiotherapy for non intestinal cancer is a significant cause of morbidity which may limit the treatment dose required. Conservative treatment options are of limited value and surgery is reserved only for the most severe complications. This review addresses radioprotection of the anorectum and aims to increase awareness amongst surgeons of the strategies that have been in practice in order to minimize the side-effects of radiotherapy while preserving its therapeutic efficacy.

METHODS

This review is based on a literature search (Medline and NLM PubMed) with manual cross-referencing of all articles related to anorectal radiation injury.

RESULTS

Optimization of radiation dose, the use of radioprotective agents and improvement in radiation delivery are the main areas of development. There are few data on the potential of altered fractionation schedules in reducing anorectal injury. A few phase I and II studies suggest that the pharmacological agents amifostine and misoprostol could be beneficial in limiting radiation damage but larger phase III studies are awaited.

CONCLUSION

The introduction of 3-dimensional conformal radiation therapy and intensity modulated radiation therapy has been the most significant advance in reducing radiation morbidity.

Análise microscópica do efeito da radioterapia fracionada em glândula submandibular de rato

OBJETIVO: O estudo teve por objetivo avaliar, quantitativamente, as alterações histológicas induzidas pela radioterapia sobre o parênquima e o estroma da glândula submandibular. MATERIAIS E MÉTODOS: A amostra foi constituída por 30 ratos Wistar, distribuídos em dois grupos: teste e controle. Os 15 animais do grupo-teste foram submetidos a radioterapia da região de cabeça e pescoço, na modalidade fracionada rotacional por cobalto-60, na dose de 60 Gy, realizada em frações de 2 Gy diários, por seis semanas. Decorridas 60 horas da conclusão da radioterapia, as glândulas submandibulares dos animais de ambos os grupos foram excisadas, processadas pela técnica da parafina, coradas com hematoxilina e eosina e analisadas à microscopia óptica. O volume proporcional médio correspondente ao parênquima e ao estroma glandulares foi obtido pelo método estereológico de contagem manual de pontos. RESULTADOS: O volume proporcional de ácinos no grupo irradiado (60,67% ± 6,43) foi significativamente menor que no grupo-controle (67,42% ± 10,90) (p = 0,048), entretanto, não houve diferença estatisticamente significativa entre os grupos para as variáveis parênquima, ductos e estroma (teste t de Student, p > 0,05). CONCLUSÃO: O esquema radioterápico empregado provocou atrofia acinar da glândula submandibular, sem, no entanto, ocorrer alteração quantitativa total do estroma ou do parênquima.

Complications after breast cancer surgery in patients treated with concomitant preoperative chemoradiation: a case–control analysis

BACKGROUND

Nearly 60% of breast cancer cases in Mexico are in advanced stages. At our institution, concomitant preoperative chemoradiation is being used in patients with advanced breast cancer. In the present study, we evaluated the postoperative wound complications and risk factors associated.

PATIENTS AND METHODS

The study included breast cancer patients from January 2000 to December 2002 treated with concomitant preoperative chemoradiation and mastectomy. Wound complication rates were described along with a nested case-control analysis to evaluate risk factors for postoperative major wound complications.

RESULTS

We evaluated 360 patients treated with preoperative chemoradiation. About 165 patients (45.8%) developed a wound complication (infection and/or flap necrosis); 60 (16.6%) patients had a surgical site infection (SSI) and 61 (16.9%), flap necrosis; 44 (12.2%) developed both complications, and 25 (6.9%) experienced late dehiscence after suture removal. Epidermolysis, seroma, and hematoma occurred in 93 (25.8%), 80 (22.2%), and 12 patients (3.3%), respectively. Case-control analysis was conducted in 335 patients. After logistic regression analysis, the sole variable found associated with SSI and/or flap necrosis was epidermolysis (OR = 8.81, 95% CI = 4.52-17.18). Although not significant and of lesser magnitude, adjusted risk estimates of overweight, age >50 years, and type of mastectomy showed the same trend.

CONCLUSIONS

Postoperative wound complications were not different from those observed in non-radiated patients, but its rate was higher. Epidermolysis was associated with SSI and/or flap necrosis. Careful surgical technique should be encouraged.

Pelvic, abdominal, and chest wall reconstruction with AlloDerm in patients at increased risk for mesh-related complications

BACKGROUND

The use of polypropylene mesh in the reconstruction of trunk defects increases complication rates when the mesh is placed directly over viscera or the operative site has been irradiated or contaminated with bacteria. An alternative is AlloDerm (decellularized human cadaveric dermis), which becomes vascularized and remodeled into autologous tissue after implantation. When used for fascial reconstruction, AlloDerm forms a strong repair, causes minimal abdominal adhesions, and resists infection.

METHODS

We did a retrospective study of cancer patients at increased risk for mesh-related complications who underwent trunk reconstruction with AlloDerm over a 1-year period. Risk factors included unavoidable placement of mesh directly over the bowel or lung, perioperative irradiation, and/or bacterial contamination of the defect. The indications, defect characteristics, reconstructive techniques, complications, and surgical outcomes were evaluated.

RESULTS

Thirteen patients were included in the study. Indications for reconstruction were oncologic resection, resection of enterocutaneous fistula, and/or ventral hernia repair. Seven patients had bacterial contamination at the operative site and seven patients received perioperative radiation. The mean musculofascial defect size was 435 cm. AlloDerm was placed directly over the bowel or lung in all patients. Nine patients required flap reconstruction, including 14 pedicled and two free flaps. The mean follow-up was 6.4 months. Complications occurred in six patients, however, there were no clinically evident mesh infections, hernias, or bulges.

CONCLUSIONS

AlloDerm successfully can be used in reconstructions for large, complex pelvic, chest, and abdominal wall defects even when placed directly over viscera and when the operative field is irradiated and/or contaminated with bacteria.

Consequences of Radiation Accidents

Radiation injury attributable to radiotherapy is a topic that has attracted ample attention in the literature, especially in a vast number of publications in plastic surgery. However, the literature is clearly devoid of compilations regarding the effects of ionized radiation accidents. A case of a radiation accident is presented. It is nearly impossible to anticipate the extent of effects of external irradiation of the skin and subcutaneous tissues. The initially healed area should be expected to show late recurrent necrosis. Patients exposed to ionized external irradiation are no longer radioactive and can be treated as ordinary patients. However, these patients should be followed closely for years, keeping in mind the onset of late radiation effects like skin necrosis in various parts of the body, skin and other organ cancers, leukemia, infertility, hypothyroidism, and cataracts.

Radioprotection: the non-steroidal anti-inflammatory drugs (NSAIDs) and prostaglandins

Clinical and experimental studies of the acute and late effects of radiation on cells have enhanced our knowledge of radiotherapy and have led to the optimisation of radiation treatment schedules and to more precise modes of radiation delivery. However, as both normal and cancerous tissues have similar response to radiation exposure, radiation-induced injury on normal tissues may present either during, or after the completion of, the radiotherapy treatment. Studies on both NSAIDs and prostaglandins have indeed shown some evidence of radioprotection. Both have the potential to increase the survival of cells but by entirely different mechanisms. Studies of cell kinetics reveal that cells in the mitotic (M) and late G2 phases of the cell cycle are generally most sensitive to radiation compared with cells in the early S and G1/G0 phases. Furthermore, radiation leads to a mitotic delay in the cell cycle. Thus, chemical agents that either limit the proportion of cells in the M and G2 phases of the cell cycle or enhance rapid cell growth could in principle be exploited for their potential use as radioprotectors to normal tissue during irradiation. NSAIDs have been shown to exert anti-cancer effects by causing cell-cycle arrest, shifting cells towards a quiescence state (G0/G1). The same mechanism of action was observed in radioprotection of normal tissues. An increase in arachidonic acid concentrations after exposure to NSAIDs also leads to the production of an apoptosis-inducer ceramide. NSAIDs also elevate the level of superoxide dismutase in cells. Activation of heat shock proteins by NSAIDs increases cell survival by alteration of cytokine expression. A role for NSAIDs with respect to inhibition of cellular proliferation possibly by an anti-angiogenesis mechanism has also been suggested. Several in-vivo studies have provided evidence suggesting that NSAIDs may protect normal tissues from radiation injury. Prostaglandins do not regulate the cell cycle, but they do have a variety of effects on cell growth and differentiation. PGE(2) mediates angiogenesis, increasing the supply of oxygen and nutrients, essential for cellular survival and growth. Accordingly, PGE(2) at sufficiently high plasma concentrations enhances cellular survival by inhibiting pro-inflammatory cytokines such as TNF-alpha and IL-1beta. Thus, PGE(2) acts as a modulator, rather than a mediator, of inflammation. Prospective studies have suggested the potential use of misoprostol, a PGE(1) analogue, before irradiation, in prevention of radiation-induced side effects. The current understanding of the pharmacology of NSAIDs and prostaglandins shows great potential to minimise the adverse effects of radiotherapy on normal tissue.

Management of carotid body tumors

The carotid body tumor is a rare neoplasm that has generated much literature over the past century, and for which continued controversy exists regarding natural history, biologic behavior, proper technique of excision, and the risk of morbidity and mortality. This article discusses overall management of carotid body tumors.

Anorectal injury following pelvic radiotherapy

BACKGROUND

Current knowledge of the effects of radiation on the anorectum is based on a limited number of studies. Variability in delivery techniques, both currently and historically, combined with a paucity of prospective and randomized studies makes interpretation of the literature difficult. This review presents the existing evidence and identifies areas that require further work.

METHODS

This review is based on a literature search (Medline and PubMed) and manual cross-referencing.

RESULTS AND CONCLUSION

More than three-quarters of patients receiving pelvic radiotherapy experience acute anorectal symptoms and up to one-fifth suffer from late-phase radiation proctitis. About 5 per cent develop other chronic complications, such as fistula, stricture and disabling faecal incontinence. The risk of rectal cancer may be increased. Conservative treatment options are of limited value. Surgery may be considered if symptoms are severe, provided sphincter function is adequate and recurrent disease is excluded. Large prospective studies with accurate dosimetric data and long-term follow-up are needed to provide meaningful information on which to base new strategies to minimize the side-effects from radiotherapy.

Laryngeal radionecrosis and hyperbaric oxygen therapy: report of 18 cases and review of the literature

Laryngeal radionecrosis is a difficult late complication of radiotherapy. It is associated with hoarseness, edema, pain, weight loss, and upper airway obstruction. The medical treatment options are limited, and in severe cases, the patient may require tracheostomy or laryngectomy. We report clinical results in 18 patients treated with adjunctive hyperbaric oxygen (HBO) therapy for severe radionecrosis of the larynx. Of these 18 patients, 2 had grade 3 and 16 had grade 4 radionecrosis. The patients received a mean number of 41 HBO treatments (range, 6 to 80) at 2 atmospheres absolute for 2 hours, twice a day, 6 days a week. Thirteen patients (72.2%) had a major improvement after HBO therapy, and none of them required total laryngectomy. All patients preserved their voice and deglutition in good or normal condition. Five patients (27.8%) failed to have a good response to HBO and underwent total laryngectomy. One of these patients had local recurrence of his cancer 4 months later, and the other 3 had significant concurrent medical problems. The remaining patient received only 6 HBO treatments because of emergency heart surgery. These encouraging results are comparable to those of smaller previous studies suggesting that HBO has a beneficial effect in the management of advanced laryngeal radionecrosis.

Effects of external beam radiation on the allograft dermal implant

OBJECTIVE

The purpose of this study was to define the effects of external beam radiation (EBR) on AlloDerm (LifeCell Corp) through the analysis of graft thickness, fibroblast recellularization, and neovascularization as a function of time.

METHODS AND MATERIAL

Thirty-six male Sprague-Dawley rats (n = 36) were randomly assigned to 1 of 4 groups (A, B, C, and D). AlloDerm was implanted subcutaneously into the hind legs of each rat, and 20 Gy of EBR was administered to one side. Grafts harvested 1, 2, 4, and 12 weeks after radiation were subjected to blinded histologic analysis.

RESULTS

In groups A, B, and C, the irradiated grafts showed a significant decrease in recellularization versus nonirradiated (P < 0.001). At 12 weeks (group D), recellularization equalized, but neovascularization was significantly less (P = 0.048) in the irradiated group. Graft thickness was unaffected.

CONCLUSIONS

In the rat model, EBR of the implanted AlloDerm graft hinders recellularization in the early posttreatment period. However, EBR did not adversely affect graft thickness, recellularization or ultimate graft survival.