Multi-Institutional Clinical Outcomes of Biopsy Gleason Grade Group 5 Prostate Cancers Treated With Contemporary High-Dose Radiation and Long-Term Androgen Deprivation Therapy

AIMS

This multicentric retrospective study reports long-term clinical outcomes of non-metastatic grade group 5 prostate cancers treated with external beam radiotherapy (EBRT) alone with long-term androgen deprivation therapy (ADT).

MATERIALS AND METHODS

Patients treated across 19 institutions were studied. The key endpoints that were evaluated were 5-year biochemical recurrence-free survival (bRFS), metastases-free survival (MFS), overall survival, together with EBRT-related acute and late toxicities. The impact of various prognostic factors on the studied endpoints was analysed using univariate and multivariate analyses.

RESULTS

Among the 462 patients, 88% (405) had Gleason 9 disease and 31% (142) had primary Gleason pattern 5. A prostate-specific membrane antigen positron emission tomography-computed tomography scan was used for staging in 33% (153), 80% (371) were staged as T3/T4 and 30% (142) with pelvic nodal disease. The median ADT duration was 24 months; 66% received hypofractionated EBRT and 71.4% (330) received pelvic nodal irradiation. With a median follow-up of 56 months, the 5-year bRFS, MFS and overall survival were 73.1%, 77.4% and 90.5%, respectively. Primary Gleason pattern 5 was associated with worse bRFS, MFS and overall survival with hazard ratios of 0.51 (95% confidence interval 0.35 to 0.73, P < 0.001), 0.64 (95% confidence interval 0.43 to 0.96, P = 0.031) and 0.52 (95% confidence interval 0.28 to 0.97, P = 0.040), respectively, whereas pelvic nodal disease was associated with worse bRFS (hazard ratio 0.67, 95% confidence interval 0.46 to 0.98, P = 0.039) and MFS (hazard ratio 0.56, 95% confidence interval 0.37 to 0.85, P = 0.006). The acute and late radiation-related toxicities were low overall and pelvic nodal irradiation was associated with higher toxicities.

CONCLUSION

Contemporary EBRT and long-term ADT led to excellent 5-year clinical outcomes and low rates of toxicity in this cohort of non-metastatic grade group 5 prostate cancers. Primary Gleason pattern 5 and pelvic node disease portends inferior clinical outcomes.

Critical Appraisal of Paediatric Embryonal Cancers Treated with Image-guided Intensity-modulated Proton Therapy

AIM

To carry out a comprehensive critical appraisal of image-guided intensity-modulated proton therapy practice for craniospinal irradiation (CSI).

MATERIALS AND METHODS

An image-guided intensity-modulated proton therapy database of 45 consecutive paediatric patients with central nervous system embryonal malignancies treated between January 2019 and April 2022 were critically appraised for demography, diagnosis, treatment planning strategy and treatment delivery accuracy.

RESULTS

Most patients (median age: 7.5 years; male:female ratio: 34:11) had medulloblastoma (56%), followed by recurrent ependymoma (19%), pinealoblastoma (5%), germ cell (5%) and others (15%). The dose to the planning target volume-craniospinal (PTV-CS; length 39.06-79.59 cm) varied from 21 to 35 GyRBE, whereas the combined median dose to craniospinal and boost was 54 GyRBE. In all patients, the 95% isodose line covered the cribriform plate completely and optic nerves mostly, with a median V95% of 100% and 82.96%, keeping Dmax to the lens <3.9 GyRBE. In skeletally immature patients (88.38%), the anterior vertebral body was completely covered in 18.18% and underdosed in 70.15% of the cases, resulting in a median Dmean of 10.11 GyRBE to the oesophagus. Lateral spine coverage was maintained on the edges of the vertebral body in 52.2%, whereas it extended beyond in 48.8%. The median V98% for clinical target volumes and V95% for PTVs of the brain, spine and craniospinal were >97%, with excellent conformity (0.89) and homogeneity (0.07) indices for PTV-CS. All neurological organs at risk received a median Dmax ranging from 36 to 44 GyRBE from the combined CSI and boost regimens. Analysis of patient-specific quality assurance results revealed that 545 (97.67%) planar dosage verification had gamma (3% at 3 mm) values >95%. The online patient set-up verification showed translational and rotational deviation within 2 mm and 0.5° in 88-94% and 97% of the cases. Systematic and random error were within 0.90 mm and 1.71 mm in translation and 0.1° and 0.2° in rotation.

CONCLUSION

A change in practice pattern was observed. The findings from our comprehensive critical appraisal add to the growing library of CSI practice and may serve as a reference for inter-institutional comparison.

Hypofractionated radiotherapy for T1N0M0 glottic cancer: retrospective analysis of two different cohorts of dose-fractionation schedules from a single institution

AIMS

To determine the influence of dose and fractionation on tumour characteristics, toxicity, disease control and survival outcomes in T1 glottic carcinoma.

MATERIALS AND METHODS

Between 1975 and 2000, treatment charts of 652 patients with T1 glottic carcinoma who received curative radiation with four hypofractionated schedules (50 Gy/15 fractions [3.3 Gy/fraction] or 55 Gy/16 fractions [3.43 Gy/fraction] or 60 Gy/24 fractions or 62.5 Gy/25 fractions [2.5 Gy/fraction]) were analysed. The patients were divided into two groups based on fraction size <3 Gy and >3 Gy. Local control and overall survival were calculated. Patient- and tumour-related factors affecting local control were analysed using univariate and multivariate analysis. Factors affecting late toxicity were also analysed.

RESULTS

The local control and overall survival at 10 years were 84 and 86.1%, respectively, for T1 glottic carcinoma. The response to radiation had a significant effect on local control with univariate analysis (P = 0.001). Other factors, such as beam energy, anterior commissure involvement and fractionation, did not affect local control. Persistent radiation oedema was seen in 123 patients (23.4%) and was significantly worse in patients who received radiation with a larger field size (>36 cm(2)) on a telecobalt machine (P < 0.001).

CONCLUSIONS

Radical radiotherapy schedules incorporating a higher dose per fraction yield acceptable local control rates and late toxicity. Telecobalt therapy for early glottic cancer is a safe alternative to treatment with 6 MV photons on a linear accelerator in terms of local control and late toxicity as long as field sizes smaller than 36 cm(2) are used.

Impact of interobserver variability in delineating clinical target volumes (CTV) for head and neck intensity modulated radiation therapy (IMRT): Potential for a geographical miss

e17013

Background: Despite modern day imaging techniques and guidelines for delineation of the clinical target volume, there remains significant inter-observer variability in delineating the CTV. With the use of IMRT, the target volume receives a significant tumoricidal dose while the regions just outside the target receive unpredictable doses. In this report, the dose to the region just outside the planning target volume (PTV) (defined as volume of uncertainty [VOU]), presumed to represent the regions subject to maximum inter-observer variability, was studied. Methods: The IMRT plans of 12 patients with head and neck cancer were used to determine the dose just outside the high-risk CTV by growing volumes around CTV with 3 mm, 5 mm, and 7 mm margins. These volumes were edited at regions close to skin/air and bone. PTVs were subsequently grown using the same margins as used in the original plans. With the Boolean operations, each of these volumes was subtracted from the existing PTV to generate the volumes of uncertainty (VOU) in 3 dimensions. The dose to these VOUs was analyzed. D95, D90 and median dose which are the doses received by 95%, 90%, and 50% of the target volume respectively were studied. Results: The median prescribed dose was 68 Gy (60 Gy-72 Gy). The median percentage D95 for 3mm, 5mm and 7mm VOU was 82.5% ± 4.95, 77.25% ± 5.53, and 69% ± 6.93, respectively. The median percentage D90 for these VOU's was 87.7% ± 3.53, 83.2% ± 4.61, and 79% ± 4.5, respectively. The median dose to each of these VOU”s was 96% ± 1.6, 94.5% ± 1.95, and 92.5% ± 1.85 respectively. Conclusions: This study documents that the volumes of uncertainty surrounding the PTV, which could contain subclinical disease, in fact receive a significant amount of RT dose. Hence, despite a large amount of evidence for inter-observer variability in target delineation for head and neck cancer,the majority of locoregional recurrences are within the high dose region and not marginal failures.

No significant financial relationships to disclose.

Implantable cardioverter defibrillator patch erosion in a heart transplant patient

A 57-year-old man who had received an automatic implantable cardioverter defibrillator and subsequent orthotopic heart transplant presented to medical attention for hemoptysis. The hemoptysis was caused by the migration of the left ventricular patch of the automatic implantable cardioverter defibrillator, which had been left in place at the time of orthotopic heart transplant. The patch had eroded into the left lung. We recommend that implantable cardioverter defibrillators be removed completely at the time of heart transplantation to prevent subsequent complications.

Prevention of peritoneal adhesions by administration of sodium carboxymethyl cellulose and oral vitamin E

BACKGROUND

Previous studies have shown that dietary supplements of vitamin E or the intraperitoneal administration of sodium carboxymethyl cellulose (SCMC) solution reduces postoperative adhesions by approximately 50%. The aim of this study was to determine whether there is a synergistic beneficial effect of vitamin E and SCMC in reducing postoperative adhesions.

METHODS

Sixty Sprague-Dawley rats were fed an identical diet containing 32 IU vitamin E/kg and were divided into four main groups: group A (control) and groups B, C, and D (experimental). Group D was further subdivided into three subgroups (D1, D2, and D3). Oral supplements of vitamin E in doses of 10 IU, 30 IU, and 30 IU/kg body weight were given to subgroups D1, D2, and D3 and group B, respectively, 5 days before operation and were continued until the fourteenth postoperative day when all animals were killed. Adhesions were created by scraping the cecum with mesh gauze followed by application of absolute alcohol and placement of silk suture in the parietal peritoneum. SCMC solution was administered intraperitoneally in groups C and D before closure. Adhesions were graded by two different investigators.

RESULTS

All control animals developed significant adhesions, compared with no adhesions in 30% of group B (vitamin E) (p < 0.04), 40% in group C (SCMC) (p = 0.0001), and an average of 90% in the D groups (SCMC+vitamin E) (p = 0.0001).

CONCLUSIONS

It appears that there is a synergistic beneficial effect of oral supplements of vitamin E and the intraperitoneal administration of SCMC solution in reducing the incidence and degree of intraperitoneal adhesions.

Antenatal spontaneous perforation of the extrahepatic biliary tree

Spontaneous perforation of the biliary system is an unusual neonatal phenomenon that is rarely recognized at birth. To date, it has not been reported antenatally. A 16-year-old pregnant adolescent had an ultrasonogram at 25 weeks of pregnancy that revealed ascites in the fetus. After the infant was delivered at 32 weeks, a hepato-iminodiacetic acid scan showed a spontaneous rupture of the common bile duct. The infant was treated with external drainage of the biliary tree and recovered well. This case demonstrates that spontaneous perforations of the bile ducts can occur much earlier than the usually described 2 to 12 weeks after birth, can be diagnosed antenatally, and should be added to the list of causes of fetal ascites.

Building an inexpensive microwave source for electrodeless discharge lamps

We demonstrate that a microwave power source to operate electrodeless discharge lamps can be built by modifying an inexpensive microwave oven at about 1/3 the cost of a commercial unit.